First Commission Directive

L-Ewwel Direttiva tal-Kummissjoni

of 13 November 1979

tat-13 ta' Novembru 1979

laying down Community methods of analysis for testing certain partly or wholly dehydrated preserved milk for human consumption

li tistabbilixxi metodi tal-Komunità ta' analiżi għal testijiet ta' ċertu ħalib ippriservat parzjalment jew kompletament deħidrat għall-konsum uman

(79/1067/EEC)

(79/1067/kee)

THE COMMISSION OF THE EUROPEAN COMMUNITIES,

Il-K1ummissjoni tal-Komunitajiet Ewropej,

Having regard to the Treaty establishing the European Economic Community,

Wara li kkunsidrat it-trattat li jistabbilixxi l-Komunità Ekonomika Ewropea,

Having regard to Council Directive 76/118/EEC of 18 December 1975 on the approximation of the laws of the Member States relating to certain partly or wholly dehydrated preserved milk for human consumption [1], and in particular Article 11 thereof,

Wara li kkunsidrat id-direttiva tal-Kunsill 76/118/KEE tat-18 ta' Diċembru 1975 dwar l-approsimazzjoni tal-liġijiet ta' l-Istati Membri rigward ċertu ħalib ippriservat parzjalment jew kompletament deħidrat għal konsum uman [1], u partikolarment l-artikolu 11 tagħha,

Whereas under Article 11 of Directive 76/118/EEC, the composition of certain partly or wholly dehydrated preserved milk is required to be verified by Community methods of analysis;

Billi taħtartikolu 11 tad-direttiva 76/118/KEE, il-kompożizzjoni ta' ċertu ħalib ippreservat parzjalment jew kompletament deħidrat hija meħtieġa li tkun verifikata b'metodi ta' analiżi tal-Komunità;

Whereas it is desirable to adopt an initial series of methods in respect of which studies have been completed;

Billi huwa mixtieq li jkunu adottati serje inizjali ta' metodi li fir-rigward tagħhom studji kienu ġew finalizzati;

Whereas the measures provided for in this Directive are in accordance with the opinion of the Standing Committee of Foodstuffs,

Billi l-miżuri provduti f'din id-direttiva huma bi qbil ma' l-opinjoni tal-kumitat permanenti għal oġġetti ta' l-ikel,

HAS ADOPTED THIS DIRECTIVE:

Adottat din id-direttiva:

Article 1

Artikolu 1

Member States shall take all measures necessary to ensure that the analyses necessary for verification of the criteria set out in Annex I are carried out in accordance with the methods described in Annex II.

Stati membri għandhom jieħdu l-miżuri kollha meħtieġa biex jiżguraw li l-analiżi meħtieġa għall-verifika tal-kriterji provduti fl-anness i ikunu mwettqa bi qbil ma' l-metodi deskritti fl-anness ii.

Article 2

Artikolu 2

Where alternative methods for a single determination are specified, the sample may be analysed by either method. The test report referred to in Annex II must state the method which has been employed.

Fejn metodi alternattivi għal determinazzjoni waħdanija huma speċifikati, il-kampjun jista' jkun analizzat bi kwalunkwe metodu. Ir-rapport tat-test li hemm referenza għalih fl-anness ii irid isemmi l-metodu li jkun ġie użat.

Article 3

Artikolu 3

Member States shall bring into force the laws, regulations and administrative provisions necessary to comply with this Directive within 18 months of its notification. They shall forthwith inform the Commission thereof.

Stati membri għandhom idaħħlu fis-seħħ il-liġijiet, regolamenti u disposizzjonijiet amministrattivi meħtieġa biex ikunu konformi ma' din id-direttiva fi żmien 18-ilxhar minn notifika tagħha. Għandhom minnufieħ jinfurmaw lill-kummissjoni dwar dan.

Article 4

Artikolu 4

This Directive is addressed to the Member States.

Din id-direttiva hija indirizzata lill-istati membri.

Done at Brussels, 13 November 1979.

Magħmula fi brussell, Fit-13 ta' novembru 1979.

For the Commission

Għall-kummissjoni

Étienne Davignon

Etienne Davignon

Member of the Commission

Membru tal-kummissjoni

[1] OJ No L 24, 30. 1. 1976, p. 49.

[1] ĠU L 24, tat-30.1.1976, p. 49.

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ANNEX I

L-ANNESS I

SCOPE OF THE FIRST COMMUNITY METHODS OF ANALYSIS FOR CERTAIN PARTLY OR . WHOLLY DEHYDRATED PRESERVED MILK DIRECTIVE

Skop ta' l-ewwel direttiva ta' metodi ta' analiżi tal-komunità għal ċertu ħalib ippreservat parzjament jew kompletament priservat

I. General provisions

I. Disposizzjonijiet ġenerali

II. Determination of dry matter in:

II. Determinazzjoni ta' materja niexfa fil-:

- unsweetened condensed high fat milk (using method 1, Annex II),

- ħalib ikkondensat mhux biz-zokkor b'xaħam għoli (bl-użu ta' metodu 1, l-anness ii).

- unsweetened condensed milk (using method 1, Annex II),

- ħalib ikkondensat mhux biz-zokkor (bl-użu ta' metodu 1, l-anness ii).

- unsweetened condensed partly skimmed milk (using method 1, Annex II),

- ħalib ikkondensat mhux biz-zokkor parzjalment xkumat (bl-użu ta' metodu 1, l-anness ii).

- unsweetened condensed skimmed milk (using method 1, Annex II),

- ħalib xkumat ikkondensat mhux biz-zokkor (bl-użu ta' metodu 1, l-anness ii).

- sweetened condensed milk (using method 1, Annex II),

- ħalib ikkondensat biz-zokkor (bl-użu ta' metodu 1, l-anness ii).

- sweetened condensed partly skimmed milk (using method 1, Annex II),

- ħalib ikkondensat biz-zokkor parzjalment xkumat (bl-użu ta' metodu 1, l-anness ii).

- sweetened condensed skimmed milk (using method 1, Annex II).

- ħalib xkumat ikkondensat biz-zokkor (bl-użu ta' metodu 1, l-anness ii).

III. Determination of moisture in:

III. Determinazzjoni ta' umdità fil-:

- dried high fat milk or high fat milk powder (using method 2, Annex II), — dried whole milk or whole milk powder (using method 2, Annex II),

- ħalib niexef b'xaħamgħoli jew trab tal-ħalib b'xaħam għoli (bl-użu ta' metodu 2, l-anness ii).

- dried partly skimmed milk or partly skimmed-milk powder (using method 2, Annex II),

- ħalib komplut niexef jew trab tal-ħalib komplut (bl-użu ta' metodu 2, l-anness ii).

- dried skimmed milk or skimmed-milk powder (using method 2, Annex II).

- ħalib niexef parzjalment xkumat jew trab tal-ħalib parzjalment xkumat (bl-użu ta' metodu 2, l-anness ii).

IV. Determination of fat in:

- ħalib niexef xkumat jew trab tal-ħalib xkumat (bl-użu ta' metodu 2, l-anness ii).

- unsweetened condensed high fat milk (using method 3, Annex II),

IV. Determinazzjoni ta' xaħam fil-:

- unsweetened condensed milk (using method 3, Annex II),

- ħalib ikkondensat mhux biz-zokkor b'xaħam għoli (bl-użu ta' metodu 3, l-anness ii).

- unsweetened condensed partly skimmed milk (using method 3, Annex II),

- ħalib ikkondensat mhux biz-zokkor (bl-użu ta' metodu 3, l-anness ii).

- unsweetened condensed skimmed milk (using method 3, Annex II),

- ħalib ikkondensat mhux biz-zokkor parzjalment xkumat (bl-użu ta' metodu 3, l-anness ii).

- sweetened condensed milk (using method 3, Annex II),

- ħalib xkumat ikkondensat mhux biz-zokkor (bl-użu ta' metodu 3, l-anness ii).

- sweetened condensed partly skimmed milk (using method 3, Annex II),

- ħalib ikkondensat biz-zokkor (bl-użu ta' metodu 3, l-anness ii).

- sweetened condensed skimmed milk (using method 3, Annex II),

- ħalib ikkondensat biz-zokkor parzjalment xkumat (bl-użu ta' metodu 3, l-anness ii).

- dried high fat milk or high fat milk powder (using method 4, Annex II),

- ħalib xkumat ikkondensat biz-zokkor (bl-użu ta' metodu 3, l-anness ii).

- dried whole milk or whole milk powder (using method 4, Annex II),

- ħalib niexef b'xaħam għoli jew trab tal-ħalib b'xaħam għoli (bl-użu ta' metodu 4, l-anness ii).

- dried partly skimmed milk or partly skimmed-milk powder (using method 4, Annex II),

- ħalib komplut niexef jew trab tal-ħalib komplut (bl-użi ta' metodu 4, l-anness ii).

- dried skimmed milk or skimmed-milk powder (using method 4, Annex II).

- ħalib niexef parzjalment xkumat jew trab tal-ħalib parzjalment xkumat (bl-użu ta' metodu 4, l-anness ii).

V. Determination of sucrose in:

- ħalib niexef xkumat jew trab tal-ħalib xkumat (bl-użu ta' metodu 4, l-anness ii).

- sweetened condensed milk (using method 5, Annex II),

V. Determinazzjoni ta' sucrose fil-:

- sweetened condensed partly skimmed milk (using method 5, Annex II),

- ħalib ikkondensat biz-zokkor (bl-użu ta' metodu 5, l-anness ii).

- sweetened condensed skimmed milk (using method 5, Annex II).

- ħalib ikkondensat biz-zokkor parzjalment xkumat (bl-użu ta' metodu 5, l-anness ii).

VI. Determination of lactic acid and lactates in:

- ħalib xkumat ikkondensat biz-zokkor (bl-użu ta' metodu 5, l-anness ii).

- dried high fat milk or high fat milk powder (using method 6, Annex II),

VI. Determinazzjoni ta' aċidu laktiku u laktiċi fil-:

- dried whole milk or whole milk powder (using method 6, Annex II),

- ħalib niexef b'xaħam għoli jew trab tal-ħalib b'xaħam għoli (bl-użu ta' metodu 6, l-anness ii).

- dried partly skimmed milk or partly skimmed-milk powder (using method 6, Annex II),

- ħalib komplut niexef jew trab tal-ħalib komplut (bl-użu ta' metodu 6, l-anness ii).

- dried skimmed milk or skimmed-milk powder (using method 6, Annex II).

- ħalib niexef parzjalment xkumat jew trab tal-ħalib parzjalment xkumat (bl-użu ta' metodu 6, l-anness ii).

VII. Determination of phosphatase activity in:

- ħalib niexef xkumat jew trab tal-ħalib xkumat (bl-użi ta' metodu 6, l-anness ii).

- dried high fat milk or high fat milk powder (using method 7 or 8, Annex II),

VII. Determinazzjoni ta' attività ta' fosfatażi fil-:

- dried whole milk or whole milk powder (using method 7 or 8, Annex II),

- ħalib niexef b'xaħam għoli jew trab tal-ħalib b'xaħam għoli (bl-użu ta' metodu 7 jew 8, l-anness ii).

- dried partly skimmed milk or partly skimmed-milk powder (using method 7 or 8, Annex II),

- ħalib komplut niexef jew trab tal-ħalib komplut (bl-użu ta' metodu 7 jew 8, l-anness ii).

- dried skimmed milk or skimmed-milk powder (using method 7 or 8, Annex II).

- ħalib niexef parzjalment xkumat jew trab tal-ħalib parzjalment xkumat (bl-użu ta' metodu 7 jew 8, l-anness ii).

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- ħalib niexef xkumat jew trab tal-ħalib xkumat (bl-użu ta' metodu 7 jew 8, l-anness ii).

ANNEX II

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METHODS OF ANALYSIS RELATING TO THE COMPOSITION OF CERTAIN PARTLY OR WHOLLY DEHYDRATED PRESERVED MILK PRODUCTS INTENDED FOR HUMAN CONSUMPTION

L-ANNESS II

GENERAL PROVISIONS

METODI TA' ANALIŻI RIGWARD IL-KOMPOSIZZJONI TA' ĊERTI PRODOTTI TAL-ĦALIB PRESERVAT PARZJALMENT JEW KOMPLETAMENT DEĦIDRAT INTENZJONAT GĦALL-KONSUM UMAN

1. PREPARATION OF THE SAMPLE FOR CHEMICAL ANALYSIS

DISPOSIZZJONIJIET ĠENERALI

1.1. Unsweetened condensed high fat milk

1. PREPARAZZJONI TAL-KAMPJUN GĦALL-ANALIŻI KEMIKALI

Unsweetened condensed milk

1.1. Ħalib ikkondensat mingħajr zokkor b'xaħam għoli

Unsweetened condensed partly skimmed milk

Ħalib ikkondensat mingħajr zokkor

Unsweetened condensed skimmed milk

Ħalib ikkondensat mingħajr zokkor parzjalment xkumat

Shake and invert the closed can. Open the can and slowly pour the milk into a second container which can be closed hermetically, mixing by repeated transfer. Ensure that all remaining fat and milk adhering to the wall and the ends of the can are mixed in with the sample. Close the container. If the contents are not homogeneous warm the container in a waterbath at 40 oC. Shake vigorously every 15 minutes. After two hours, remove the container from the water-bath and let it cool to room temperature. Remove the lid and thoroughly mix the contents of the container with a spoon or spatula (if the fat has separated the sample should not be tested). Store in a cool place.

Ħalib ikkondensat mingħajr zokkor xkumat

1.2. Sweetened condensed milk

Ħawwad u aqleb ta' taħt fuq il-bott magħluq. Iftaħ il-bott u bil-mod ferra' l-ħalib ġo tieni kontenitur li jista' jkun magħluq ermetikament, thawwad billi taqleb ripetutament. Żgura li l-kumplament kollu tax-xaħam u l-ħalib li jkun weħel mal-ġnub u t-trufijiet tal-bott ikunu mħallta mal-kampjun. Aġħlaq il-kontenitur. Jekk il-kontenuti ma jkunux omoġeniji, saħħan il-kontenitur f'banju ta' l-ilma f'40 °C. Ħawwad b'qawwa kull 15-ilminuta. Wara sagħtejn, neħħi l-kontenitur mill-banju ta' l-ilma u ħallieħ jiiksaħ għat-temperatura tal-kamra. Neħħi l-għatu u ħawwad sew il-kontenut tal-kontenitur b'mgħarfa jew spatula (jekk ix-xaħam ikun issepara, il-kampjun m'għanux ikun itestjat). Aħżen f'post frisk.

Sweetened condensed partly skimmed milk

1.2. Ħalib ikkondensat biz-zokkor

Sweetened condensed skimmed milk

Ħalib ikkondensat biz-zokkor parzjalment xkumat

Cans: Warm the closed can in a waterbath at 30 to 40 oC for about 30 minutes. Open the can and thoroughly mix the contents with a spatula or a spoon by making upward, downward, and circular movements in order to obtain an intimate mixture of the top and bottom layers with all the contents. Ensure that the remaining milk adhering to the wall and end of the can is incorporated in the sample. As far as possible, pour the contents into a second container provided with an air-tight lid. Close the container and store in a cool place.

Ħalib xkumat ikkondensat biz-zokkor

Tubes: Cut the end and pour the contents into a container provided with an air-tight lid. Next, cut the tube lengthwise. Scrape out all material adhering to the interior and mix it carefully with the rest of the contents. Store the container in a cool place.

Bottijiet: saħħan il-bott magħluq f'banju ta' l-ilma fi 30 sa 40 °C għal ma dwar 30 minuta. Iftaħ il-bott u ħawwad sew il-kontenut bi spatula jew mgħarfa billi tagħmel movimenti l-fuq, l-isfel u irkolari sabiex takkwista taħlita intima tas-saffi ta' fuq u t'isfel mal-kontenut kollhu. Żgura li l-kumplament tal-ħalib li jkun weħel mal-ġnub u t-trufijiet tal-bott ikun inkorporat mal-kampjun. Kemm jista' jkun possibbli, ferra' l-kontenuti ġo tieni kontenitur li jkun ipprovvdut b'għatu li jagħlaq ermetikament. Agħlaq il-kontenitur u aħżen f'post frisk.

1.3. Dried high fat milk or high fat milk powder

Tubi: aqta' t-tarf u ferra' l-kontenut ġo kontenitur li jkun ipprovvdut b'għatu li jagħlaq ermetikament. Imbagħad, aqta t-tubu mit-tul. Imsaħ il-materjal kollu li jkun imwaħħal mal-ġewwieni u ħawwdu b'galbu mal-kumplament tal-kontenuti. Aħżen il-kontenitur f'post frisk.

Dried whole milk or whole milk powder

1.3. Ħalib niexef b'xaħam għoli jew trab tal-ħalib b'xaħam għoli

Dried partly skimmed milk or partly skimmed-milk powder

Ħalib komplut niexef jew trab ta' ħalib komplut

Dried skimmed milk or skimmed-milk powder

Ħalib niexef parzjalment xkumat jew trab ta' ħalib parzjalment xkumat

Transfer the milk powder to a clean, dry container (with air-tight lid) of a capacity of twice the volume of the powder. Close the container immediately and thoroughly mix the milk powder by repeatedly shaking and inverting the container. During the preparation of the sample exposure of the milk powder to the atmosphere should be avoided as far as possible to minimize absorption of moisture.

Ħalib xkumat niexef jew trab ta' ħalib xkumat

2. REAGENTS

Trasferixxi t-trab tal-ħalib ġewwa kontenitur nadif u niexef (b'għatu li jgħalaq ermetikament) ta' kapaċità ta' darbtejn l-volum tat-trab. Agħlaq il-kontenitur immedjatament u ħallat sew it-trab tal-ħalib billi ripetutament tħawwad u taqleb il-kontenitur. Matul il-preparazjoni tal-kampjun, l-esposizzjoni tat-trab tal-ħalib għall-attmosfera għandu jkun evitat kemm jista' jkun possibbli biex jixrob umidità mill-inqas.

2.1. Water

2. REAĠENTI

2.1.1. Wherever mention is made of water for dissolution, dilution or washing purposes, distilled water, or demineralized water of at least equivalent purity shall be used.

2.1. Ilma

2.1.2. Wherever reference is made to "dissolution", "solution" or "dilution" without further indication, "dissolution in water", "solution in water" and "dilution in water" is meant.

2.1.1. Kull fejn hemm referenza għall-ilma għal skopijiet ta' tħollija, tidwib jew għall-ħasil, ilma distillat, jew ilma demineralizzat ta' mill-inqas purità ekwivalenti għandu jkun użat.

2.2. Chemicals

2.1.2. Kull meta ssir referenza għal "tħollija", "soluzzjoni" jew "tidwib" mingħajr aktar indikazzjoni, "taħlit fl-ilma", "soluzzjoni fl-ilma" u "tħollija fl-ilma" għandu jkun mifhum.

All chemicals used shall be of recognized analytical reagent quality except where otherwise specified.

2.2. Kemikali

3. EQUIPMENT

Il-kemikali kollha wżati għandhom ikunu ta' kwalità ta' reaġent analitiku rikonoxxut ħlief meta jkun hemm speċifikat mod ieħor.

3.1. Lists of equipment

3. TGĦAMIR

The lists of equipment contain only those items with a specialized use and items with a particular specification.

3.1. Lista ta' tgħamir

3.2. Analytical balance

Il-listi ta' tgħamir fihom biss dawk l-oġġetti b'użu speċifikat u oġġetti bi speċifikazjoni partikolari.

Analytical balance means a balance capable of weighing to at least 0,1 mg.

3.2. Miżien analitiku

4. EXPRESSION OF RESULTS

Miżien analitiku jfisser miżien kapaċi li jiżen mill-anqas 0.1 mg.

4.1. Calculation of percentage

4. ESPRESSJONI TAR-RIŻULTATI

Except where otherwise specified, the results shall be calculated as a percentage by mass of the sample as received by the laboratory.

4.1. Kalkolazzjoni ta' persentaġġi

4.2. Number of significant figures

Ħlief meta jkun speċifikat mod ieħor, ir-riżultati għandhom ikunu kkalkolati bħala persentaġġ bil-massa tal-kampjun kif akkwistat mil-laboratorju.

The result shall not contain more significant figures than are justified by the precision of the method of analysis used.

4.2. Numru ta' figuri sinifikanti

5. TEST REPORT

Ir-riżultat m'għandux ikun fih aktar figuri sinifikanti milli huma ġġustifikati bil-preċiżjoni tal-metodu ta' analiżi wżat.

The test report shall identify the method of analysis used as well as the results obtained. In addition, it shall mention all details of procedure not specified in the method of analysis, or which are optional, as well as any circumstances that may have influenced the results obtained.

5. RAPPORT TAT-TEST

The test report shall give all the information necessary for the complete identification of the sample.

Ir-rapport tat-test għandu jidentifika l-metodu ta' analiżi wżat kif ukoll ir-riżultati akkwistati. B'żieda, għandu jsemmi d-dettalji kollha tal-proċedura mhux speċifikati fil-metodu ta' analiżi, jew li huma volontarji, kif ukoll xi ċirkostanzi li setgħu kellhom influwenza fuq ir-riżultati akkwistati.

METHOD 1: DETERMINATION OF DRY MATTER CONTENT

Ir-rapport tat-test għandu jgħati l-informazzjoni kollha meħtieġa għall-identifikazzjoni sħieħa tal-kampjun.

(oven 99 oC)

METODU 1: DETERMINAZZJONI TA' KONTENUT TA' MATERJA NIEXFA

1. SCOPE AND FIELD OF APPLICATION

(forn 99 °C)

This method determines the dry matter content of:

1. SKOP U QASAM TA' APPLIKAZZJONI

- unsweetened condensed high fat milk,

Dan il-metodu jiddetermina l-kontenut ta' materja niexfa ta':

- unsweetened condensed milk,

- ħalib ikkondensat mingħajr zokkor b'xaħam għoli,

- unsweetened condensed partly skimmed milk,

- ħalib ikkondensat mingħajr zokkor,

- unsweetened condensed skimmed milk,

- ħalib ikkondendat mingħajr zokkor parzjalment xkumat,

- sweetened condensed milk,

- ħalib xkumat ikkondensat mingħajr zokkor,

- sweetened condensed partly skimmed milk,

- ħalib ikkondensat biz-zokkor,

- sweetened condensed skimmed milk.

- ħalib ikkondensat biz-zokkor parzjalment xkumat,

2. DEFINITION

- ħalib ikkondensat biz-zokkor xkumat.

The dry matter content of condensed milks: dry matter content as determined by the method specified.

2. DEFINIZZJONI

3. PRINCIPLE

Il-kontenut ta' materja niexfa ta' ħalibb ikkondensat: il-kontenut ta' materja niexfa kif determint bil-metodu speċifikat.

A known amount of the sample is diluted with water, mixed with sand and dried at a temperature of 99 oC ± 1 oC. The mass after drying is the mass of dry matter and is calculated as a percentage by mass of the sample.

3. PRINĊIPJU

4. REAGENTS

Ammont magħruf tal-kampjun huwa mdewweb ma' l-ilma, imħallat ma ramel u mnixxef f'temperatura ta 99 °C aktar jew anqas 1 °C. Il-massa wara t-tnixxif hija l-massa tal-materja niexfa u hija kkalkolata bħala persentaġġ bil-massa tal-kampjun.

Quartz sand or sea sand, treated with hydrochloric acid (size of the grains: 0,18 to 0,5 mm, that is passing through a 500 micron sieve and retained by a 180 micron sieve). It should meet the following control test:

4. REAĠENTI

Heat about 25 g of sand for two hours in the drying oven (5.3) as described in 6.1. to 6.3. Add 5 ml of water, heat again in the oven for two hours, cool and reweigh. The difference between the two masses should not exceed 0,5 mg.

Ramel tal-kwartz jew ramel tal-baħar, trattat b'aċidu idrokloriku (daqs tar-ramla): 0.18 sa 0.5 mm, jiġifieri li jgħaddi minn għarbiel ta' 500 micron sieve u miżmum minn għarbiel ta' 180 micron sieve). Għandu jilħaq dan it-test ta' kontroll li ġej:

If necessary treat the sand with a 25 % hydrochloric acid solution for three days, mixing occasionally. Wash with water until the acid reaction disappears or the wash water is chloride free. Dry at 160 oC and re-test as above.

Saħħan madwar 25 g ta' ramel għal sagħtejn ġo forn tat-tnixxif (5.3) kif deskritt f'6.1. Sa 6.3. Żid 5 ml ta' ilma, saħħan mill-ġdid fil-forn għal sagħtejn, kessaħ u iżen mill-ġdid. Id-differenza bejn iż-żewġ mases m'għandiex teċċedi 0.5 mg.

5. APPARATUS

Jekk meħtieġ tratta r-ramel b'soluzzjoni ta' 25 % aċidu idrokloriku għal tlett ijiem, tħawwad ta' kull tant. Aħsel bl-ilma sakemm ir-reazjoni ta' l-aċidu tisparixxi jew li l-ilma tal-ħasil ikun ħieles mill-kloridu nixxef fi 160 °C u għamel test mill-ġdid bħal t'hawn fuq.

5.1. Analytical balance.

5. APPARAT

5.2. Metal dishes, preferably of nickel, aluminium or stainless steel. The dishes must have lids which fit very well but which are readily removed. Suitable dimensions are: diameter 60 to 80 mm and depth about 25 mm.

5.1. Miżien analitiku.

5.3. Atmospheric-pressure drying oven, well ventilated, thermostatically controlled with temperature regulated at 99 oC ± 1 oC. The temperature should be uniform throughout the oven.

5.2. Dixxijiet tal-metal, preferebilment tan-nikil, aluninju jew azzar inossidabbli. Id-dixxijiet għandu ikollhom għotien li jagħlqu sewwa imma li jkunu jistgħu jitneħħew mingħajr tbatija. Qisien xierqa huma: dijametru 60 sa 88 mm u fond ta' ma dwar 25 mm.

5.4. Desiccator, containing freshly activated silica gel with a water content indicator or an equivalent desiccant.

5.3. Forn ta' tnixxif ta' pressjoni atmosferika, ivventilat sewwa, termostatitkament ikkontrollat b'temperatura rregolata fi 99 °C aktar jew anqas 1 °C. It-temperatura għandha tkun uniformi matul il-forn kollu.

5.5. Glass rods, flattened at one end of such a length that they can fit inside the metal dishes (5.2).

5.4. Dessikatur, li jkun fih silica gel attivata friska b'indiktaur ta' kontenut ta' ilma jew ta' dessikant ekwivalenti.

5.6. Waterbath, boiling.

5.5. Virgi tal-ħġieġ, ċatti minn naħa waħda ta' tul tali li jkunu jistgħu joqgħodu fid-dixxijiet tal-metall (5.2).

6. PROCEDURE

5.6. Banju ta' l-ilma, jaghli

6.1. Place about 25 g sand (4) and a short glass rod (5.5) in the dish (5.2).

6. PROĊEDURA

6.2. Without covering the dish and contents with the lid, place the dish, contents and lid in the oven (5.3) and heat for two hours.

6.1. Qiegħed madwar 25 g ta' ramel (4) u virga qasira tal-ħġieġ (5.5) f'dixx (5.2).

6.3. Replace lid and transfer the dish to the desiccator (5.4). Allow to cool to room temperature and accurately weigh to the nearest 0,1 mg (M0).

6.2. Mingħajr ma tgħatti d-dixx u l-kontenut bil-għatu, qiegħed id-dixx, il-kontenut u l-għatu fil-forn (5.3) u saħħan għal madwar sagħtejn.

6.4. Tilt the sand to one side of the dish. Introduce into the clear space about 1,5 g of the sample of sweetened condensed milk and 3,0 g of unsweetened condensed milk. Replace the lid and accurately weigh to the nearest 0,1 mg (M1).

6.3. Poġġi lura l-għatu u trasferixxi d-dixx fid-dissekatur (5.4). Ħalli jiksaħ għat-temperatura tal-kamra u b'eżatezza iżen lejn l-eqreb 0.1 mg (m0).

6.5. Remove the lid, add 5 ml of water and, with the aid of the glass rod, mix the liquids and then the sand and the liquid portion. Leave the rod in the mixture.

6.4. Aqleb ir-ramel lejn naħa waħda tad-dixx. Fl-ispazju vġut introdui madwar 1.5 g tal-kampjun ta' ħalib biz-zokkor ikkondensat u 3.0 g ta' ħalib ikkondensat mingħajr zokkor. Erġa poġġi l-għatu u b'eżatezza iżen lejn l-eqreb 0.1 mg (m1).

6.6. Place the dish on a boiling waterbath (5.6) until the water has evaporated; this usually takes 20 minutes. Stir the mixture from time to time with the rod to keep the mass well aerated so that the mass when dry does not form a cake. Lay the rod inside the dish.

6.5. Neħħi l-għatu, żid 5 ml ta' ilma u, bl-għajnuna tal-virga tal-ħġieġ, ħawwad il-likwidi u imbagħad ir-ramel u l-porzjon tal-likwidu. Ħalli l-virga fit-taħlita.

6.7. Place the dish and lid in the oven for one and a half hours.

6.6. Qiegħed id-dixx fuq banju ta' l-ilma li jkun jagħli (5.6) sa-kemm l-ilma jkun evapora; dan normalment jieħu madwar 20 minuta. Ħawwad it-taħlita minn ħin għall-ieħor bil-virga biex iżżomm il-massa mimlija bl-arja hekk li meta l-massa tinxef ma ssirx ċappa. Midd il-virga ġewwa d-dixx.

6.8. Replace the lid, transfer the dish to the desiccator (5.4), allow to cool to room temperature and accurately weigh to the nearest 0,1 mg.

6.7. Qiegħed id-dixx u l-għatu fil-forn għal siegħa u nofs.

6.9. Replace the dish and lid in the oven, uncover the dish and heat it with its lid for a further hour.

6.8. Poġġi lura l-għatu, trasferixxi d-dixx lejn id-dissekatur (5.4), ħalli jiksaħ lejn it-temperatura tal-kamra u b'eżatezza iżen l-eqreb 0.1 mg.

6.10. Repeat process 6.8.

6.9. Poġġi lura d-dixx u l-għatu fil-forn, ikxef id-dixx u saħnu flimkien ma l-għatu għal siegħa oħra.

6.11. Repeat the described processes 6.9 and 6.10 until the difference in mass of two successive weighings is less than 0.5 mg or until the mass increases. If an increase in mass occurs use the lowest mass obtained in the calculation (7.1). Let the final weight recorded be M2 g.

6.10. Irrepeti l-proċess 6.8.

7. EXPRESSION OF RESULTS

6.11. Irrepeti l-proċessi deskriti f' 6.9 u 6.10 sakemm id-differenza fil-massa ta' żewġ piżijiet suċċessivi tkun ta' anqas minn 0.5 mg jew sakemm il-massa tiżdied. Jekk żieda fil-massa sseħħ, uża l-massa l-aktar baxxa kif akkwistata fil-kalkolazzjoni (7.1). Ħalli li l-piż finali rreġistrat ikun m2 g.

7.1. Method of calculation

7. ESPRESSJONI TAR-RIŻULTATI

The content of dry matter, calculated as a percentage by mass of the sample, is given by:

7.1. Metodu ta' kalkolazzjoni

×100

Il-kontenut ta' materja niexfa, ikkalkolat bħala persentaġġ b'massa tal-kampjun, huwa mogħti bi:

where:

M0 = mass, in g of the dish, lid and sand after process 6.3;

- M

M1 = mass, in g of the dish, lid, sand and sample after process 6.4;

M2 = mass, in g of the dish, lid, sand and dried sample after process 6.11.

- M

7.2. Repeatability

× 100

Fejn:

8. CALCULATION OF TOTAL MILK SOLIDS AND MILK SOLIDS NOT FAT

M0 = massa, fi g tad-dixx, għatu u ramel wara il-proċess 6.3;

8.1. The total milk solids content of the sweetened condensed milk is given by:

M1 = massa, fi g tad-dixx, għatu, ramel u kampjun wara il-proċess 6.4;

Total dry matter (obtained by method 1, Annex II) — sucrose (obtained by method 5, Annex II).

M2 = massa, fi g tad-dixx, għatu, ramel u kampjun niexef wara proċess 6.11.

8.2. The milk solids not fat content of the sweetened condensed milks is given by:

7.2. Repetabilità

Total dry matter (obtained by method 1, Annex II) — (sucrose content obtained by method 5, Annex II) and fat content (obtained by method 3, Annex II).

8.3. The milk solids not fat content of unsweetened condensed milks is given by:

8. KALKOLAZZJONI TAS-SOLIDI TOTALI FIL-ĦALIB U SOLIDI TAL-ĦALIB BLA XAĦAM

Total dry matter (obtained by method 1, Annex II) — fat content (obtained by method 3, Annex II).

8.1. Il-kontenut totali ta' solidi tal-ħalib ta' ħalib ikkondensat biz-zokkor huwa muri bi:

METHOD 2: DETERMINATION OF MOISTURE

Materja niexfa totali (akkwistata b'metodu 1, l-anness II) - sucrose (akkwistat b'metodu 5, l-anness II).

(oven 102 oC) .

8.2. Il-kontenut bla xaħam ta' solidi tal-ħalib ta' ħalib ikkondensat biz-zokkor huwa muri bi:

1. SCOPE AND FIELD OF APPLICATION

Materja niexfa totali (akkwistata b'metodu 1, l-anness II) - (kontenut sucrose akkwistat b'metodu 5, l-anness II) u kontenut ta' xaħam (akkwistat b'metodu 3, l-anness II).

This method determines the loss of mass on drying of:

8.3. Il-kontenut bla xaħam ta' solidi ta' ħalib ikkondensat mhux biz-zokkor huwa muri bi:

- dried high fat milk or high fat milk powder,

Materja niexfa totali (akkwistata b'metodu 1, l-anness II) - kontenut ta' xaħam (akkwistat b'metodu 3, l-anness II).

- dried whole milk or whole milk powder,

METODU 2: DETERMINAZZJONI TA' UMDITÀ

- dried partly skimmed milk or partly skimmed-milk powder,

(forn 102 °C)

- dried skimmed milk or skimmed-milk powder.

1. Skop u qasam ta' l-applikazzjoni

2. DEFINITION

Dan il-metodu jiddetermina t-telf ta' massa fit-tnixxif ta':

Moisture content: the loss of mass on drying as determined by the method specified.

- ħalib niexef b'xaħam għoli jew trab tal-ħalib b'xaħam għoli,

3. PRINCIPLE

- ħalib komplut niexef jew trab ta' ħalib komplut,

The residual mass of a test portion is determined after drying at atmospheric pressure in an oven at 102 oC ± 1 oC to constant mass. The loss of mass is calculated as a percentage by mass of the sample.

- ħalib niexef parzjalment xkumat jew trab tal-ħalib parzjalment xkumat,

4. APPARATUS

- ħalib xkumat niexef jew trab tal-ħalib xkumat.

4.1. Analytical balance.

2. DEFINIZZJONI

4.2. Dishes, preferably of nickel, aluminium, stainless steel or glass. The dishes must have lids which fit very well but which can readily be removed. Suitable dimensions are: diameter 60 to 80 mm and depth about 25 mm.

Kontenut ta' umdità: it-telf ta' massa mat-tnixxif kif determinat bil-metodu speċifikat.

4.3. Atmospheric-pressure drying oven, well ventilated, thermostatically controlled with temperature regulation (at 102 oC ± 1 oC). The temperature should be uniform throughout the oven.

3. PRINĊIPJU

4.4. Desiccator, containing freshly activated silica gel with a water content indicator or an equivalent desiccant.

Il-massa residwa tal-porzjon tat-test hija ddeterminata wara t-tnixxif fi pressa atmosferika ġo forn fi 102 °C aktar jew anqas 1 °C għal massa konsistenti. It-telf ta' massa huwa kkalkolat bħala persentaġġ b'massa tal-kampjun.

5. PROCEDURE

4. APPARAT

5.1. Uncover the dish (4.2) and place it and its lid in the oven (4.3) and heat for about one hour.

4.1. Miżien analitiku.

5.2. Place the lid on the dish and transfer the covered dish to the desiccator (4.4). Allow it to cool to room temperature and accurately weigh to the nearest 0,1 mg (Mo).

4.2. Dixxijiet, preferibilment tan-nikil, aluminju, azzar inossidabbli jew ħġieġ. Id-dixxijiet għanduikollhom għotien li jagħlqu sewwa imma li jkun jistgħu jitneħħew mingħajr tbgħatija. Qisien xierqa huma: dijametru 60 sa 80 mm u fond ta' ma dwar 25 mm.

5.3. Introduce approximately 2 g of dried milk sample into the dish, cover the dish with the lid and accurately weigh to the nearest 0,1 mg the covered dish as quickly as possible (M1).

4.3. Forn ta' tnixxif ta' pressjoni atmosferika, ivventilat sewwa, termostatitkament ikkontrollat b'temperatura rregolata (fi 102 °C aktar jew anqas 1 °C). It-temperatura għandha tkun uniformi ma-tul il-form kollu.

5.4. Uncover the dish and put it with its lid in the oven for two hours.

4.4. Dessikatur, li jkun fih silica gel attivata friska bi ndiktaur ta' kontenut ta' ilma jew ta' dessikant ekwivalenti.

5.5. Replace the lid, transfer the covered dish to the desiccator, allow it to cool to room temperature and accurately weigh to the nearest 0,1 mg as quickly as possible.

5. PROĊEDURA

5.6. Uncover the dish and heat it and its lid for one hour in the oven.

5.1. Ikxef id-dixx (4.2) u qiegħdu u l-għatu tiegħu fil-forn (4.3) u saħħan għal madwar siegħa.

5.7. Repeat process 5.5.

5.2. Qiegħed l-għatu fuq id-dixx u trasferixxi d-dixx mogħtti lejn id-dessikatur (4.4). Ħalli jiksaħ għat-temperatura tal-kamra u b'eżatezza iżen lejn l-eqreb 0.1 mg (m0).

5.8. Repeat processes 5.6 and 5.5 until the decrease in mass between the successive weighings does not exceed 0,5 mg or until the mass increases. If an increase in mass occurs use the lowest mass obtained in the calculation (6.1). Let the final weight recorded be M2 g.

5.3. Introdui madwar 2 g ta' kampjun ta' ħalib niexef fid-dixx, agħtti d-dixx bl'għatu u b'eżatezza iżen lejn l-eqreb 0.1 mg id-dixx mgħotti malajr kemm jista' jkun possibbli (m1).

6. EXPRESSION OF RESULTS

5.4. Ikxef id-dixx u qiegħdu bl'għatu tiegħu fil-forn għal sagħtejn.

6.1. Method of calculation

5.5. Poġġi lura l-għatu, trasferixxi d-dixx lejn id-dessikatur, ħallih jibred għat-temperatura tal-kamra u b'eżatezza iżen lejn l-eqreb 0.1 mg malajrkemm jista' jkun possibbli.

Calculate the loss of mass on drying of the sample, expressed as a percentage by mass, by the formula:

5.6. Ikxef id-dixx u saħħnu bl'għatu tiegħu fil-forn għal siegħa waħda.

×100

5.7. Irrepeti l-proċess 5.5.

where:

5.8. Irrepeti l-proċessi 5.6 u 5.5 sakemm it-tnaqqis fil-massa bejn iż-zewġ piżijiet suċessivi ma jeċċedix 0.5 mg jew sakemm il-massa tiżdied. Jekk żieda fil-massa sseħħ uża l-massa l-aktar baxxa kif akkwistata fil-kalkolazjoni (6.1). Ħalli li l-piż finali rreġistrat ikun m2 g.

M0 = mass, in g of the dish and its lid after process 5.2;

6. ESPRESSJONI TAR-RIŻULTATI

M1 = mass, in g of the dish, its lid and sample after process 5.3;

6.1. Metodu ta' kalkolazjoni

M2 = mass, in g of the dish, its lid and final sample after process 5.5.

Ikkalkola t-telf fil-massa meta tnixxef il-kampjun, espress bħala perċentwal skond il-massa, bil-formola

6.2. Repeatability

The difference in results between two determinations carried out simultaneously or in rapid succession on the same sample, by the same analyst, under the same conditions, shall not exceed 0,1 g of moisture per 100 g of product.

- M

METHOD 3: DETERMINATION OF FAT CONTENT IN CONDENSED MILKS (RÖSE-GOTTLIEB METHOD)

1. SCOPE AND FIELD OF APPLICATION

- M

This method determines the fat content of:

× 100

- unsweetened condensed high fat milk,

Fejn:

- unsweetened condensed milk,

M0 = il-massa, f'g tad-dixx u l-għatu tiegħu wara l-proċess 5.2;

- unsweetened condensed partly skimmed milk,

M1 = il-massa, f'g tad-dixx u l-għatu tiegħu wara l-proċess 5.3;

- unsweetened condensed skimmed milk,

M2 = il-massa, f'g tad-dixx u l-għatu tiegħu wara l-proċess 5.5;

- sweetened condensed milk,

6.2. Repetabilità

- sweetened condensed partly skimmed milk,

- sweetened condensed skimmed milk.

METODU 3: DETERMINAZZJONI TA' KONTENUT TA' XAĦAM FIL-ĦALIB IKKONDENSAT (METODU RÖSE-GOTTLIEB)

2. DEFINITION

1. SKOP U QASAM TA' APPLIKAZZJONI

The fat content of condensed milks: fat content as determined by the method specified.

Dan il-metodu jiddetermina l-kontenut ta' xaħam ta':

3. PRINCIPLE

- ħalib ikkondensat mingħajr zokkor b'xaħam għoli,

The fat content is determined by extraction of the fat from an ammoniacal alcoholic solution of the sample with diethyl ether and light petroleum followed by evaporation of the solvents and weighing of the residue and calculation as a percentage by mass of the sample, according to the principle of Rose-Gottlieb.

- ħalib ikkondensat mingħajr zokkor,

4. REAGENTS

- ħalib ikkondensat mingħajr zokkor parzjalment xkumat,

All reagents should conform to the requirements specified in the blank test (6.1). If necessary, reagents may be redistilled in the presence of about 1 g of butterfat for 100 ml of solvent.

- ħalib ikkondensat mingħajr zokkor xkumat,

4.1. Ammonia solution, approximately 25 % (m/m) NH3 (density at 20 oC approximately 0.91 g/ml), or a stronger solution of known concentration.

- ħalib ikkondensat biz-zokkor,

4.2. Ethanol, 96 ± 2 % (v/v) or, if not available, ethanol denatured with methanol, ethyl methyl ketone or light petroleum.

- ħalib ikkondensat biz-zokkor parzjalment xkumat,

4.3. Diethyl ether, peroxide-free.

- ħalib xkumat ikkondensat biz-zokkor.

Note 1:

2. DEFINIZZJONI

To test for peroxides, add to 10 ml of the ether in a small glass stoppered cylinder, previously rinsed with the ether, 1 ml freshly prepared 10 % potassium iodide solution. Shake and let stand for one minute. No yellow colour should be observed in either layer.

Il-kontenut ta' xaħam ta' ħalib ikkondensat: il-kontenut ta' xaħam kif determint bil-metodu speċifikat.

Note 2:

3. PRINĊIPJU

Diethyl ether may be maintained free from peroxides by adding wet zinc foil that has been completely immersed in dilute acidified copper sulphate solution for one minute and subsequently washed with water. Use per litre approximately 8000 mm2 zinc foil; cut in strips long enough to reach at least halfway up the container.

Il-kontenut ta' xaħam huwa determinat bl-estrazzjoni tax-xaħam minn soluzzjoni alkoħolika ammonjaka tal-kampjun b'etere dijeteliku u petroleum ħafif segwit b'evporazjoni tas-solventi u iżen ir-residwi u ikkalkola bħala persentaġġ bil-massa tal-kampjun, skond il-prinċipju ta' röse-gottlieb.

4.4. Light petroleum (petroleum ether), with any boiling range between 30 and 60 oC.

4. REAĠENTI

4.5. Mixed solvent, prepared shortly before use by mixing equal volume of diethyl ether (4.3) and light petroleum (4.4) (where the use of mixed solvent is indicated, it may be replaced by either diethyl ether or light petroleum alone).

Ir-reaġenti kollha għandhom ikunu konformi mall-ħtiġijiet speċifikati fit-test vġut (6.1). Jekk meħtieġ, reaġenti jistgħu jkunu ddistillati mill-ġdid fil-preżenza ta' madwar 1 g ta' xaħam tal-butir għal 100 ml ta' solvent.

5. APPARATUS

4.1. Soluzzjoni ta' ammonja, approssimament 25 % (m/m) nh3 (densità fi 20 °C approssimament 0.91 g/ml), jew soluzzjoni aktar qawwija ta' konċentrazzjoni magħrufa.

5.1. Analytical balance.

4.2. Etanol, 96 aktar jew anqas 2 % (v/v) jew, jekk mhux disponibbli, etanol denaturaliżżat b'metanol, ethyl methyl ketone jew petroleum ħafif.

5.2. Suitable extraction tubes or flasks, provided with ground glass stoppers or other closures un-. affected by the solvents used.

4.3. Etere dijeteliku, ħieles mill-perossidu.

5.3. Flasks, thin-walled and flat-bottomed, 150 to 250 ml capacity.

Nota 1:

5.4. Atmospheric pressure drying oven, well ventilated and thermostatically controlled (adjusted to operate at 102 oC ± 1 oC.

Biex ikun hemm test għall-perossidu, żid ma 10 ml ta' etere f'ċilindru żgħir tal-ħġieġ li jkollu tapp, imlaħlaħ minn qabel bl-etere, 1 ml ta' soluzzjoni ta' 10 % jodju tal-potassju ippreparat frisk. Ħawwad u ħallieħ joqgħod għall-minuta waħda. L-ebda kulur isfar m'għandu jkun osservat f'xi saff.

5.5. Anti-bumping granules, fat-free, non porous, non friable in use, e.g. glass beads or pieces of silicon carbide (the use of this material is optional; see clause 6.2.1.

Nota 2:

5.6. Siphon, to fit extraction tubes.

Etere dijeletiku jista' jinżamm ħieles mill-perossidi biż-żieda ta' folja ta' żingu mxarrba li tkun ġiet kompletament imdaħħla f'soluzzjoni likwida ta' sulfat tar-ramm aċidifikat għal minuta waħda u sussegwentement maħsulha bl-ilma. Uża għal kull litru madwar 8000 mm2 ta' folja taż-żingu; maqtuha fi strippi twal biżżejjed biex jilħqu mill-anqas san-nofs tal-kontenitur.

5.7. Centrifuge (optional).

4.4. Petroleum ħafif (etere tal-petroleum), bi kwalunkwe medda ta' tgħollija bejn 30 u 60 °C.

6. PROCEDURE

4.5. Solvent imħallat, ippreparat ftit qabel l-użu bit-taħltit ta' volum ugwali ta' eteru dijeteliku (4.3) u petroleum ħafif (4.4) (meta l-użu ta' solvent imħallat huwa ndikat, dan jista' jkun mibdul jew b'eteru dijeteliku jew petroleum ħafif biss).

6.1. Blank test

5. APPARAT

At the same time as the determination of the fat content of the sample, carry out a blank determination on 10 ml of water using the same type of extraction apparatus, the same reagents in the same amounts and the same procedure as described hereafter, excluding clause 6.2.2. If the blank exceeds 0.5 mg, the reagents should be checked and the impure reagent or reagents should be purified or replaced.

5.1. Miżien analitiku.

6.2. Determination

5.2. Tubi jew kunjetti xierqa ta' l-estrazzjoni, ipprovduti b'tappini ta' ħġieġ magħruk jew b'għeluq ieħor li ma jkunx affetwat bis-solventi wżati.

6.2.1. Dry a flask (5.3) (together with, if required, some anti-bumping granules (5.5) to promote gentle boiling during the subsequent removal of the solvents) in the oven (5.4) for half to one hour. Allow the flask to cool to the temperature of the balance room and accurately weigh the cooled flask to the nearest 0,1 mg.

5.3. Kunjetti, bi ħġieġ irqieq u qiegħ ċatt, kapaċità 150 sa 250 ml

6.2.2. Stir the prepared sample and immediately weigh, to the nearest 1 mg, 2 to 2,5 g of the sample if sweetened or 4 to 5 g of the sample if unsweetened directly in, or by difference into, the extraction apparatus (5.2). Add water to 10,5 ml and shake gently with slight warming (40 to 50 oC) until the product is completely dispersed. The sample must be dispersed completely otherwise the determination should be repeated.

5.4. Forn ta' tnixxif ta' pressjoni atmosferika, ivventilat sewwa u termostatikament ikkontrollat (aġġustat li jaħdem fi 102 °C aktar jew anqas 1 °C).

6.2.3. Add 1,5 ml ammonia (25 %) (4.1) or a corresponding volume of a stronger solution, and mix well.

5.5. Frak ta' kontra l-ħbit, ħieles minn xaħmijiet, mhux poruż, li ma jitfarrakx fl-użu, e.ż. żibeġ tal-ħġieġ jew bċejjeċ ta' silicon carbide (l-użu ta' dan il-materjal huwa voluntarju; ara klawsola 6.2.1).

6.2.4. Add 10 ml ethanol (4.2) and mix the liquids gently but thoroughly in the unclosed apparatus.

5.6. Sifun, li jorbot mat-tubi ta' l-estrazzjoni.

6.2.5. Add 25 ml diethyl ether (4.3). Cool under running water. Close the apparatus and shake vigorously and invert repeatedly for one minute.

5.7. Ċentrifuga (voluntarja).

6.2.6. Remove the stopper carefully and add 25 ml light petroleum (4.4) using the first few millilitres to rinse the stopper and inside of the neck of the apparatus, allowing the rinsings to run into the apparatus. Close by replacing the stopper and shake and invert repeatedly for 30 seconds. Do not shake too vigorously if centrifuging is not to be used in 6.2.7.

6. PROĊEDURA

6.2.7. Allow the apparatus to stand until the upper liquid layer has become clear and has distinctly separated from the lower aqueous layer. Alternatively carry out the separation using a suitable centrifuge (5.7).

6.1. Test vġut

Note:

Fl-istess waqt tad-determinazzjoni tal-kontenut tax-xaħam tal-kampjun, agħmel determinazzjoni vġuta fuq 10 ml ta' ilma billi tuża l-istess tip ta'apparat ta' estrazzjoni, l-istess reaġenti fl-istes ammonti u l-istess proċedura kif deskritta minn hawn il-quddiem, teskludi klawsola 6.2.2. Jekk il-vġut jeċċedi 0.5 mg, ir-reaġenti għandhom ikunu ivverifikati u r-reaġent jew reaġenti mhux puri għandhom jkunu ppurifikati jew mibdula.

When a centrifuge which is not driven by a three-phase motor, is used, sparks may occur and care must therefore be taken to avoid an explosion or fire from any ether vapours, coming, for example, from a broken tube.

6.2. Determinazzjoni

6.2.8. Remove the stopper, rinse it and the inside of the neck of the apparatus with a few millilitres of mixed solvent (4.5) and allow the rinsings to run into the apparatus. Carefully transfer as much as possible of the supernatant layer by decantation or by means of a siphon (5.6) into the pre pared flask (6.2.1).

6.2.1. Nixxef kunjett (5.3) (flimkien ma', jekk meħtieġ, xi ftit frak ta' kontra l-ħbit (5.5) biex tinkorraġixxi tgħolija ġentili matul it-tneħħija sussegwenti tas-solventi) ġewwa forn (5.4) għal nofs siegħa. Ħalli l-kunjett jiksaħ lejn it-temperatura tal-kamra tal-miżien u b'eżattezza iżen il-kunjett kiesaħ lejn l-eqreb 0.1 mg.

Note:

6.2.2. Ħawwad il-kampjun ippreparat u immedjatament iżen, lejn l-eqreb 1 mg, 2 sa 2.5 g tal-kampjun jekk biz-zokkor jew 4 sa 5 g tal-kampjun jekk mhux biz-zokkor, direttament fil, jew b'differenza fil, l-apparat ta' l-estrazzjoni (5.2). Żid ilma sa 10.5 ml u ħawwad ħafif bi sħana ħafifa (40 sa 50 °C sakemm il-prodott ikun kompletament imxerred. Il-kampjun għandu jkun imxerred kompletament inkella d-determinazzjoni għandha tkun irrepetuta.

If the transfer is not made using a siphon, it may be necessary to add a little water in order to raise the interface between the two layers thus aiding decantation.

6.2.3. Żid 1.5 ml ammonja (25 %) (4.1) jew volum korrisspondenti ta' soluzzjoni aktar b'saħħitha, u ħawwad sewwa.

6.2.9. Rinse the outside and the inside of the neck of the apparatus or the tip and the lower part of the siphon with a few millilitres of mixed solvent (4.5). Allow the rinsings from the outside of the apparatus to run into the flask and the rinsings from the inside of the neck and from the siphon to run into the extraction apparatus.

6.2.4. Żid 10 ml etanol (4.2) u ħawwad ħafif imma sewwa il-likwidi fl-apparat li ma jkunx magħluq.

6.2.10. Make a second extraction by repeating the procedure of 6.2.5 to 6.2.9 inclusive but using only 15 ml diethyl ether and 15 ml light petroleum.

6.2.5. Żid 25 ml eteru dijeteliku (4.3). Kessaħ taħt ilma ġieri. Agħlaq l-apparat u ħawwad bil-qawwi u aqleb repetutament għal minuta waħda.

6.2.11. Make a third extraction by repeating the procedure of 6.2.10 but omit the final rinsing (6.2.9).

6.2.6. Neħħi t-tapp bil-galbu u żid 25 ml ta' petroleum ħafif (4.4) tuża l-ewwel ftit millilitri biex tlaħlaħ it-tapp u l-ġewwieni ta' l-għonq ta' l-apparat, tippermetti li t-tlaħlieħ jinżel fl-apparat. Agħlaq billi tpoġġi t-tapp u ħawwad u aqleb repetutament għal 30 sekonda. Tħawwadx b'qawwa żejda jekk ma jkunx ser jiġi wżat entrifugar fi 6.2.7.

Note:

6.2.7. Ħalli l-apparat joqgħod sakemm is-saff ta' fuq tal-likwidu jkun sar ċar u jkun issepara distintament mis-saff akweju ta' taħt. Bħala alternativa wettaq is-separazzjoni billi tuża ċentrifuga addattata (5.7).

It is not mandatory to carry out this third extraction when analysing skimmed unsweetened condensed milk and skimmed sweetened condensed milk samples.

Nota:

6.2.12. Carefully evaporate or distil off as much solvent (including the ethanol) as possible. If the flask is of small capacity, it will be necessary to remove some of the solvent as above after each extraction.

Meta ċentrifuga li ma tkunx imħaddma b'mutur ta' tliet-fażijiet tkun użata, jistgħu jseħħu xrar u attenzzjoni għandha għalhekk tittieħed biex tkun evitata xi splużjoni jew nar minn xi fwar ta' l-etere, li jkun ġej, per eżempju, minn tubu miksur.

6.2.13. When there is no appreciable odour of solvent place the flask on its side in the oven and heat for one hour.

6.2.8. Neħħi t-tapp, laħalħu u l-ġewwieni ta' l-għonq ta' l-apparat bi ftit millilitri ta' solvent imħallat (4.5) u ppermetti t-tlaħliħiet li jinżlu fl-apparat. Ittrasferixxi bil-galbu kemm jista' jkun possibbli is-saff supernanti b'dekantazzjoni jew permezz ta' sifun (5.6) fill-'kunjett ppreparat (6.2.1).

6.2.14. Remove the flask from the oven, allow to cool to the temperature of the balance room and accurately weigh to the nearest 0,1 mg.

Nota:

6.2.15. Repeat 6.2.13 and 6.2.14 for heating periods of 30 to 60 minutes until the difference in mass of two successive weighings is less than 0.5 mg or until the mass increases. If an increase in mass occurs use the lowest mass obtained in the calculation (7.1). Let the final weight recorded be M1 g.

Jekk it-trasferiment ma jkunx magħmul b'sifun, jista' jkun meħtieġ li jiżdied xi ftit ilma sabiex tittella l-interfażi bejn iż-żewġ saffi b'hekk tgħin id-dekantazzjoni.

6.2.16. Add 15 to 25 ml light petroleum in order to confirm that the extracted matter is wholly soluble. Warm gently and swirl the solvent until all the fat is dissolved.

6.2.9. Laħlaħ barra u ġewwa ta' l-għonq ta' l-apparat jew it-tarf u l-parti t'isfel tas-sifun bi ftit millilitri ta' solvent imħallat (4.5). Ħalli t-tlaħlieħ minnbarra ta' l-apparat jinżel fill-kunjett u t-tlaħlieħ minnġewwa ta' l-għonq u mis-sifun jinżel fl-apparat ta' l-estrazzjoni.

6.2.16.1. If the extracted matter is wholly soluble in the light petroleum, the mass of fat is the difference between the weights determined at stages 6.2.1 and 6.2.15.

6.2.10. Agħmel it-tieni estrazzjoni billi tirrepeti l-proċedura ta' 6.2.5 sa 6.2.9 inklussivi imma uża biss 15 ml etere dijeteliku u 15 ml petroleum ħafif.

6.2.16.2. If any insoluble matter is present, or in case of doubt, completely extract the fat from the flasks by repeated washing with warm light petroleum, allowing the undissolved material to settle before each decantation. Rinse the outside of the neck of the flask three times. Heat the flask, placed on its side, for one hour in the oven, allow to cool to the temperature of the balance room as before (6.2.1) and weigh to the nearest 0,1 mg. The mass of fat is the difference between the mass obtained at 6.2.15 and this final mass.

6.2.11. Agħmel it-tielet estrazzjoni billi tirrepeti l-proċedura ta' 6.2.10 imma ħalli barra t-tlaħlieħ ta' l-aħħar (6.2.9).

7. EXPRESSION OF RESULTS

Nota:

7.1. Calculation

Mhux mandatorju li titwettaq din it-tielet estrazzjoni meta ssir l-analiżi ta' kapjuni ta' ħalib ikkondensat xkumat mhux biz-zokkor u ta' ħalib ikkondensat xkumat biz-zokkor.

The mass, in g of fat extracted is:

6.2.12. Bil-galbu evapora jew iddistilla kemm jista' jkun possibbli mis-solvent (inkluż l-etanol). Jekk il-kunjett huwa ta' kapaċità żgħira, ikun meħtieġ li tneħħi xi ftit mis-solvent bħal hawn fuq wara kull estrazzjoni.

(M1 — M2) — (B1 — B2)

6.2.13. Meta ma jkun hemm l-ebda rieħa apprezzabbli tas-solvent, qiegħed il-kunjett fuq il-ġenb tiegħu fil-forn u saħħan għal siegħa

and the fat content of the sample, expressed as a percentage is:

6.2.14. Neħħi l-kunjett mill-forn, ħallih jiksaħ lejn it-temperatura tal-kamra tal-miżien u b'eżattezza iżen lejn l-eqreb 0.1 mg.

×100

6.2.15. Irrepeti 6.2.13 u 6.2.14 għal perjodi ta' sħana ta' 30 sa 60 minuta sakemm id-differenza fil-massa taż-zewġ piżijiet suċessivi tkun anqas minn 0.5 mg jew sakemm il-massa tiżdied. Jekk żieda fil-massa sseħħ, uża l-massa l-aktar baxxa kif akkwistata fil-kalkolazzjoni (7.1). Ħalli li l-piż finali rreġistrat ikun m1 g.

where:

6.2.16. Żid 15 sa 25 ml ta' petroleum ħafif sabiex tikkonferma li l-materja estratta tkun tinħall kollha. Saħħan ħafif u dawwar is-solvent sakemm ix-xaħam kollu jkun inħall.

M1 = mass, in g of flask M with fat after stage 6.2.15;

6.2.16.1. Jekk il-materja estratta tkun tinħall kollha f'petroleum ħafif, il-massa ta' xaħam hija d-differenza bejn il-piżijiet determinati fi stadji 6.2.1 u 6.2.15.

M2 = mass, in g of flask M after stage 6.2.1 or, in the case of undissolved material or doubt, stage 6.2.16.2;

6.2.16.2. Jekk xi materja li ma tinħallx tkun preżenti, jew f'każ ta' dubju, estratta kompletament x-xaħam mill-kunjetti billi tirrepeti l-ħasil b'petroleum ħafif imsaħħan, u tippermetti li l-materja mhux maħlula toqgħod qabel kull dekantazzjoni. Laħlaħ barra ta' l-għonq tal-kunjett tliet darbiet. Saħħan il-kunjett, mqiegħd fuq il-ġenb tiegħu, għal siegħa waħda fil-forn, ħallih jiksaħ għat-temperatura tal-kamra ta' l-użin bħal qabel (6.2.1.) U iżen lejn l-eqreb 0.1 mg. Il-massa tax-xaħam hija d-differenza bejn il-massa akkwistata fi 6.2.15 u din il-massa finali.

B1 = mass, in g of flask B of the blank after stage 6.2.15;

7. ESPRESSJONI TAR-RIŻULTATI

B2 = mass, in g of flask B after stage 6.2.1 or, in the case of undissolved material or doubt, stage 6.2.16.2;

7.1. Kalkolazjoni

S = mass, in g of sample used.

Il-massa, fi g ta' xaħam estratt hija:

7.2. Repeatability

The difference between results of two determinations carried out obtained simultaneously or in rapid succession on the same sample, by the same analyst, under the same conditions, shall not exceed 0,05 g fat per 100 g of the product.

B1 - B2

METHOD 4: DETERMINATION OF FAT CONTENT IN DRIED MILKS (RÖSE-GOTTLIEB METHOD)

U l-kontenut tax-xaħam tal-kampjun, espress bħala persentaġġ huwa:

1. SCOPE AND FIELD AND APPLICATION

This method determines the fat content of:

× 100

- dried high fat milk or high fat milk powder,

Fejn:

- dried whole milk or whole milk powder,

M1 = massa, fi g ta' kunjett m bix-xaħam wara stadju 6.2.15;

- dried partly skimmed milk or partly skimmed-milk powder,

M2 = massa, fi g ta' kunjett m wara stadju 6.2.1, fil-każ ta' materja mhiex maħlulha jew dubju, stadju 6.2.16.2;

- dried skimmed milk or skimmed-milk powder.

S = massa, fi g tal-kampjun użat.stadju 6.2.16.2;

2. DEFINITION

B1 = massa, fi g ta' kunjett b tal-vġut wara stadju 6.2.15;

The fat content of dried milks: fat content as determined by the method specified.

B2 = massa, fi g ta' kunjett b wara stadju 6.2.1, fil-każ ta' materja mhiex maħlulha jew dubju,

3. PRINCIPLE

7.2. Repetabilità

The fat content is determined by extraction of the fat from an ammoniacal alcoholic solution of sample with diethyl ether and light petroleum, followed by evaporation of the solvents and weighing of the residue and calculation as a percentage by mass of the sample, according to the principle of Rose-Gottlieb.

Id-differenza fir-riżultati bejn iż-żewġ determinazzjonijiet imwettqa u akkwistati simultanjament jew f'segwenza magħġla fuq l-istess kampjun, mill-istess analista, taħt l-istess kondizzjonijiet, m'għandux jeċċedi 0.05 g ta' xaħam għal kull 100 g tal-prodott.

4. REAGENTS

METODU 4: DETERMINAZZJONI TA' KONTENUT TA' XAĦAM FIL-ĦALIB NIEXEF

All reagents should conform to the requirements specified in the blank test (6.1). If necessary, reagents may be redistilled in the presence of about 1 g of butterfat per 100 ml of solvent.

(metodu röse-gottlieb)

4.1. Ammonia solution, approximately 25 % (m/m) NH3 (density at 20 oC approximately 0.91 g/ml), or stronger solution of known concentration.

1. SKOP U QASAM TA' APPLIKAZZJONI

4.2. Ethanol, 96 ± 2 % (v/v) or, if not available, ethanol denatured with methanol, ethyl methyl ketone or light petroleum.

Dan il-metodu jiddetermina l-kontenut ta' xaħam ta':

4.3. Diethyl ether, peroxide-free

- ħalib niexef b'xaħam għoli jew trab tal-ħalib b'xaħam għoli,

Note 1:

- ħalib komplut niexef jew trab ta' ħalib komplut,

To test for peroxide, add to 10 ml of the ether in a small glass stoppered cylinder, previously rinsed with the ether, 1 ml freshly prepared 10 % potassium iodide solution. Shake and let stand for one minute. No yellow colour should be observed in either layer.

- ħalib niexef parzjalment xkumat jew trab ta' ħalib parzjalment xkumat,

Note 2:

- ħalib niexef xkumat jew trab ta' ħalib xkumat.

Diethyl ether may be maintained free from peroxides by adding wet zinc foil that has been completely immersed in dilute acidified copper sulphate solution for one minute and subsequently washed with water. Use per litre approximately 8000 mm2 zinc foil cut in strips long enough to reach at least halfway up the container.

2. DEFINIZZJONI

4.4. Light petroleum (petroleum ether), with any boiling range between 30 and 60 oC.

Il-kontenut ta' xaħam ta' ħalib niexef: il-kontenut ta' xaħam kif determint bil-metodu speċifikat.

4.5. Mixed solvent, prepared shortly before use by mixing equal volumes of diethyl ether (4.3) and light petroleum (4.4) (when the use of mixed solvent is indicated, it may be replaced by either diethyl ether or light petroleum alone).

3. PRINĊIPJU

5. APPARATUS

Il-kontenut ta' xaħam huwa ddeterminat bl-estrazzjoni tax-xaħam minn soluzzjoni alkoħolika ammonjaka tal-kampjun b'etere dijeteliku u petroleum ħafif, segwit b'evporazzjoni tas-solventi u il-piżijiet tar-residwi u l-kalkolazzjoni bħala persentaġġ bil-massa tal-kampjun, skond il-prinċipju ta' röse-gottlieb.

5.1. Analytical balance.

4. REAĠENTI

5.2. Suitable extraction tubes or flasks, provided with ground glass stoppers or other closures unaffected by the solvents used.

5.3. Flasks, thin-walled, flat-bottomed, of 150 to 250 ml capacity.

4.1. Soluzzjoni ta' ammonja, approssimament 25 % (m/m) nh3 (densità f'20 °C approssimament 0.91 g/ml), jew soluzzjoni aktar qawwija ta' konċentrazzjoni magħrufa.

5.4. Atmospheric pressure drying oven, well ventilated and thermostatically controlled (adjusted to operate at 102 oC ± 1 oC).

4.2. Etanol, 96 aktar jew anqas 2 % (v/v) jew, jekk mhux disponibbli, etanol denaturaliżżat b'metanol, ethyl methyl ketone jew petroleum ħafif.

5.5. Anti-bumping granules, fat-free, non porous, non friable in use, e.g. glass beads or pieces of silicon carbide (the use of this material is optional: see clause 6.2.1).

4.3. Etere dijeteliku, ħieles mill-perossidu.

5.6. Waterbath, at 60 to 70 oC.

Nota 1:

5.7. Siphon to fit extraction tubes.

Biex ikun hemm test għall-perossidu, żid ma' 10 ml ta' etere f'ċilindu żgħir tal-ħġieġ li jkollu tapp, imlaħlaħ minn qabel bl-etere, 1 ml ta' soluzzjoni ta' jodju tal-potassju ippreparat frisk. Ħawwad u ħallieh joqgħod għal minuta waħda. L-ebda kulur isfar m'għandu jkun osservat fis-saff ta' l-etere.

5.8. Centrifuge (optional).

Nota 2:

6. PROCEDURE

Etere dijeteliku jista' jinżamm ħieles mill-perossidi biż-żieda ta' folja ta' żingu mxarrba li tkun ġiet kompletament imdaħħla f'soluzzjoni likwida ta' sulfat tar-ramm aċidifikat għal minuta waħda u sussegwentament maħsulha bl-ilma. Uża għal kull litru madwar 8000 mm2 ta' folja taż-żingu; maqtuha fi strippi twal biżżejjed biex jilħqu mill-anqas sa nofs il-kontenitur.

6.1. Blank test

4.4. Petroleum ħafif (etere tal-petroleum), bi kwalunkwe medda ta' tgħollija bejn 30 u 60 °C.

At the same time as the determination of the fat content of the sample, carry out a blank determination on 10 ml of water using the same type of extraction apparatus, the same reagents in the same amounts and the same procedure as described hereafter, excluding clause 6.2.2. If blank exceeds 0.5 mg, the reagents should be checked and the impure reagent or reagents should be purified or replaced.

4.5. Solvent imħallat, ippreparat ftit qabel l-użu billi tħallait volumi ugwali ta' eteru dijeteliku (4.3) u petroleum ħafif (4.4) (meta l-użu ta' solvent imħallat huwa ndikat, dan jista' jkun mibdul jew b'eteru dijeteliku jew petroleum ħafif biss).

6.2. Determination

5. APPARAT

6.2.1. Dry the flask (5.3) together with, if required, some anti-bumping granules (5.5) to promote gentle boiling during the subsequent removal of the solvents) in the oven (5.4) for half to one hour. Allow the flask to cool to the temperature of the balance room and accurately, weigh the cooled flask to the nearest 0,1 mg.

5.1. Miżien analitiku.

6.2.2 Accurately weigh, to the nearest 1 mg, directly in, or by difference into, the extraction apparatus (5.2) about 1 g of whole milk powder or about 1,5 g of partly skimmed or skimmed-milk powder. Add 10 ml water and shake gently until the milk powder is completely dispersed (heat may be necessary for some samples).

5.2. Tubi jew kunjetti xierqa ta' l-estrazzjoni, ipprovduti b'tappini ta' ħġieġ magħruk jew b'għeluq ieħor li ma jkunx affetwat bis-solvent użat.

6.2.3. Add 1.5 ml ammonia (25 %) (4.1) or a corresponding volume of a stronger solution and heat in a waterbath (5.6) for 15 minutes at 60 to 70 oC, shaking occasionally. Cool, for example, in running water.

5.3. Kunjetti, bi ħġieġ irqieq u qiegħ ċatt, ta' kapaċità ta'150 sa 250 ml.

6.2.4. Add 10 ml ethanol (4.2) and mix the liquids gently but thoroughly in the unclosed apparatus.

5.4. Forn ta' tnixxif ta' pressjoni atmosferika, ivventilat sewwa u termostatitkament ikkontrollat (aġġustat li jaħdem fi 102 °C aktar jew anqas 1 °C).

6.2.5. Add 25 ml diethyl ether (4.3). Cool in running water. Close the apparatus and shake vigorously and invert repeatedly for one minute.

5.6. Banu ta' l-ilma fi 60 sa 70 °C.

5.7. Sifun, li jorbot mat-tubi ta' l-estrazzjoni.

Note:

5.8. Ċentrifuga (voluntarja).

When a centrifuge which is not driven by a three-phase motor is used, sparks may occur and care must therefore be taken to avoid an explosion or fire from any ether vapours coming, for example, from a broken tube.

6. PROĊEDURA

6.1. Test vġut

Note:

Fl-istess waqt tad-determinazzjoni tal-kontenut tax-xaħam tal-kampjun, agħmel determinazzjoni vġuta fuq 10 ml ta' ilma billi tuża l-istess tip ta' apparat ta' estrazzjoni, l-istess reaġenti fl-istess ammonti u l-istess proċedura kif deskritta minn hawn 'il quddiem, teskludi klawsola 6.2.2. Jekk il-vġut jeċċedi 0.5 mg, ir-reaġenti għandhom ikunu ivverifikati u r-reaġent jew reaġenti mhux puri għandhom jkunu ppurifikati jew mibdula.

If the transfer is not made using a siphon, it may be necessary to add a little water in order to raise the interface between the two layers thus aiding decantation.

6.2. Determinazzjoni

6.2.9. Rinse the outside and the inside of the neck of the apparatus or the tip and the lower part of the siphon with a few millilitres of mixed solvent. Allow the rinsings from the outside of the appara tus to run into the flask and the rinsings from the inside of the neck and from the siphon to run into the extraction apparatus.

6.2.1. Nixxef il-kunjett (5.3) (flimkien ma', jekk meħtieġ, xi ftit frak ta' kontra l-ħbit (5.5) biex tinkorraġixxi tgħolija ġentili matul it-tneħħija sussegwenti tas-solventi) ġewwa forn (5.4) għal nofs siegħa sa siegħa waħda. Ħalli l-kunjett jiksaħ lejn it-temperatura tal-kamra tal-miżien u b'eżattezza iżen il-kunjett kiesaħ lejn l-eqreb 0.1 mg.

6.2.10. Make a second extraction by repeating the procedure of 6.2.5 to 6.2.9 inclusive but using only 15 ml diethyl ether and 15 ml light petroleum.

6.2.2. B'eżattezza iżen, lejn l-eqreb 1 mg, direttament fil-, jew b'differenza fil-, l-apparat ta' estrazzjoni (5.2) madwar 1 g ta' trab ta' ħalib komplut jew madwar 1.5 g ta' trab ta' ħalib parzjalment xkumat jew ħalib xkumat. Żid 10 ml ilma u ħawwad ħafif sakemm it-trab tal-ħalib ikun kompletament imxerred (is-sħana tista' tkun meħtieġa għal xi kampjuni).

6.2.11. Make a third extraction by repeating the procedure of 6.2.10 but omit the final rinsing (6.2.9).

6.2.3. Żid 1.5 ml ammonja (25 %) (4.1) jew volum korrispondenti ta' soluzzjoni aktar qawwija u saħħan f'banju ta' l-ilma (5.6) għal 15-ilminuta fi 60 sa 70 °C billi tħawwad ta' kulltant, kessaħ, per eżempju, f'ilma ġieri.

Note:

6.2.4. Żid 10 ml etanol (4.2) u ħawwad ħafif imma sewwa l-likwidi fl-apparat li ma jkunx magħluq.

It is not mandatory to carry out this third extraction when analysing dried skimmed milk samples.

6.2.5. Żid 25 ml eteru dijeteliku (4.3). Kessaħ f'ilma ġieri. Agħlaq l-apparat u ħawwad bil-qawwi u aqleb ripetutament għal minuta waħda.

6.2.12. Carefully evaporate or distil off as much solvent (including the ethanol) as possible. If the flask is of small capacity it will be necessary to remove some of the solvent as above after each extraction.

6.2.6. Neħħi t-tapp bil-galbu u żid 25 ml ta' petroleum ħafif (4.4) billi l-ewwel tuża ftit millilitri biex tlaħlaħ it-tapp u l-ġewwieni ta' l-għonq ta' l-apparat, tippermetti li t-tlaħlieħ jinżel fl-apparat. Agħlaq billi tpoġġi t-tapp u tħawwad u taqleb ripetutament għal 30 sekonda. Tħawwadx b'qawwa żejda jekk ma jkunx ser jiġi wżat ċentrifugar fi 6.2.7.

6.2.13. When there is no appreciable odour of solvent, place the flask on its side in the oven and heat for one hour.

6.2.7. Ħalli l-apparat joqgħod sakemm is-saff ta' fuq tal-likwidu jsir ċar u jkun issepara distintament mis-saff akweju ta' taħt. Bħala alternativa wettaq is-separazzjoni billi tuża ċentrifuga addattata (5.8).

6.2.14. Remove the flask from the oven, allow to cool to the temperature of the balance room as previously (6.2.1) and accurately weigh to the nearest 0,1 mg.

Nota:

6.2.15. Repeat 6.2.13 and 6.2.14 for heating periods of 30 to 60 minutes until the difference in mass of two successive weights is less than 0,5 mg or until the mass increases. If an increase in mass occurs use the lowest mass obtained in the calculation (7.1). Let the final weight recorded be M1 g.

Meta ċentrifuga li ma tkunx imħaddma b'mutur ta' tliet fażijiet tkun użata, jistgħu jseħħu xrar u għalhekk għandha tittieħed attenzjoni biex tkun evitata xi splużjoni jew nar minn xi fwar ta' l-etere, li jkun ġej, per eżempju, minn tubu miksur.

6.2.16. Add 15 to 25 ml light petroleum in order to confirm that the extracted matter is wholly soluble. Warm gently and swirl the solvent until all the fat is dissolved.

6.2.8. Neħħi t-tapp, laħalħu u l-ġewwieni ta' l-għonq ta' l-apparat bi ftit millilitri ta' solvent imħallat (4.5) u ppermetti li t-tlaħliħiet jinżlu fl-apparat. Bil-galbu ttrasferixxi kemm jista' jkun possibbli mis-saff supernanti b'dekantazzjoni jew permezz ta' sifun (5.7) f'kunjett ppreparat (6.2.1).

6.2.16.1. If the extracted matter is wholly soluble in the light petroleum, the mass of fat is the difference between the weights determined at stages 6.2.1 and 6.2.15.

Nota:

6.2.16.2. If any insoluble matter is present, or in case of doubt completely extract the fat from the flask by repeated washing with warm light petroleum, allowing the undissolved material to settle before each decantation. Rinse the outside of the neck of the flask three times.

Jekk it-trasferiment ma jkunx magħmul b'sifun, jista' jkun meħtieġ li jiżdied xi ftit ilma sabiex tittella l-interfażi bejn iż-żewġ saffi b'hekk tgħin id-dekantazzjoni.

Heat the flask, placed on its side, for one hour in the oven, allow to cool to the temperature of the balance room, as before (6.2.1) and weigh to the nearest 0,1 mg. The mass of fat is the difference between the mass under 6.2.15 and this final mass.

6.2.9. Laħlaħ barra u ġewwa ta' l-għonq ta' l-apparat jew it-tarf u l-parti t'isfel tas-sifun bi ftit millilitri ta' solvent imħallat. Ħalli t-tlaħlieħ minn barra ta' l-apparat jinżel fil-kunjett u t-tlaħlieħ mill-ġewwieni ta' l-għonq u mis-sifun jinżel fl-apparat ta' l-estrazzjoni.

7. EXPRESSION OF RESULTS

6.2.10. Agħmel it-tieni estrazzjoni billi tirrepeti l-proċedura ta' 6.2.5 sa 6.2.9 inklużi imma uża biss 15 ml etere dieteliku u 15 ml petroleum ħafif.

7.1. Calculation

6.2.11. Agħmel it-tielet estrazzjoni billi tirrepeti l-proċedura ta' 6.2.10 imma ħalli barra t-tlaħlieħ ta' l-aħħar (6.2.9).

The mass, in g of fat extracted is:

Nota:

(M1 — M2) — (B1 — B2)

Mhux mandatorju li titwettaq din it-tielet estrazzjoni meta ssir l-analiżi tal-kampjuni ta' ħalib xkumat niexef.

and the fat content of the sample, expressed as a percentage, is:

6.2.12. Bil-galbu evapora jew iddistilla kemm jista' jkun possibbli mis-solvent (inkluż l-etanol). Jekk il-kunjett huwa ta' kapaità żgħira, jkun meħtieġ li tneħħi xi ftit mis-solvent bħal hawn fuq wara kull estrazzjoni.

×100

6.2.13. Meta ma jkun hemm l-ebda riħa apprezzabbli tas-solvent, qiegħed il-kunjett fuq il-ġenb tiegħu fil-forn u saħħan għal siegħa waħda.

where:

6.2.14. Neħħi l-kunjett mill-forn, ħallih jiksaħ lejn it-temperatura tal-kamra tal-miżien bħal qabel (6.2.1) u b'eżattezza iżen lejn l-eqreb 0.1 mg.

M1 = mass, in g of flask M with fat after stage 6.2.15;

6.2.15. Irrepeti 6.2.13 u 6.2.14 għal perjodi ta' sħana ta' 30 sa 60 minuta sakemm id-differenza fil-massa taż-zewġ piżijiet suċessivi tkun anqas minn 0.5 mg jew sakemm il-massa tiżdied. Jekk żieda fil-massa sseħħ, uża l-massa l-aktar baxxa kif akkwistata fil-kalkolazjoni (7.1). Ħalli li l-piż finali rreġistrat ikun m1 g.

M2 = mass, in g of flask M after stage 6.2.1 or, in the case of undissolved material or doubt, stage 6.2.16.2;

6.2.16. Żid 15 sa 25 ml ta' petroleum ħafif sabiex tikkonferma li l-materja estratta tkun tinħall kollha. Saħħan ħafif u dawwar is-solvent sa-kemm il-grass kollu jkun inħall.

B1 = mass, in g of flask B of the blank after stage 6.2.15;

6.2.16.1. Jekk il-materja estratta tkun tinħall kollha f'petroleum ħafif, il-massa ta' xaħam hija d-differenza bejn il-piżijiet determinati fi stadji 6.2.1 u 6.2.15.

B2 = mass, in g of flask B after stage 6.2.1 or, in the case of undissolved material or doubt, stage 6.2.16.2;

S = mass, in g of sample used.

Saħan il-kunjett, qiegħed fuq il-ġenb tiegħu, għal siegħa waħda fil-forn, ħallih jiksaħ għat-temperatura tal-kamra ta' l-użin, bħal qabel (6.2.1.) U iżen lejn l-eqreb 0.1 mg. Il-massa tax-xaħam hija d-differenza bejn il-massa akkwistata fi 6.2.15 u din il-massa finali.

7.2. Repeatability

7. ESPRESSJONI TAR-RIŻULTATI

The difference between results of two determinations carried out simultaneously or in rapid succession on the same sample, the same analyst, under the same conditions, shall not exceed 0,2 g fat per 100 g of product with the exception of skimmed-milk powder for which the difference must not exceed 0,1 g fat per 100 g of product.

7.1. Il-kalkoluu

METHOD 5: DETERMINATION OF SUCROSE CONTENT (POLARIMETERIC METHOD)

Il-massa, f'g tax-xaħam estratt hija

1. SCOPE AND FIELD OF APPLICATION

This method determines the sucrose content of:

B1 - B2

- sweetened condensed milk,

U l-kontentut tax-xaħam tal-kampjun, espress bħala perċentwal, huwa

- sweetened condensed partly skimmed milk,

- sweetened condensed skimmed milk.

× 100

Samples must not contain invert sugar.

Fejn:

2. DEFINITION

M1 = il-massa f'g tal-flixkun m bix-xaħam wara l-istadju 6.2.15 -

The sucrose content of sweetened condensed milks: the sucrose content as determined by the method specified.

M2 = il-massa, f'g tal-flixkun wara l-istadju 5.2.1 jew, fil-każ ta' materjal mhux maħlul jew dubju, l-istadju 6.2.16.2;

3. PRINCIPLE

B1 = il-massa f'g tal-flixkun b tal-battal wara l-istadju 6.2.25;

The method is based on the principle of the Clerget inversion, a mild treatment of the sample with acid which produces complete hydrolysis of sucrose but almost none of lactose or other sugars. The sucrose content is obtained from the change in rotating power of the solution.

B2 = il-massa, f'g tal-flixkun wara l-istadju 6.2.1 jew, fil-każ ta' materjal mhux maħlul jew dubju, l-istadju 6.2.16.2;

A clear filtrate of the sample, without mutarotation by lactose, is prepared by treatment of the solution with ammonia followed by neutralization and clearing by the successive addition of zinc acetate and potassium hexacyanoferrate II solutions.

S = il-massa, f'g tal-kampjun użat.

In a portion of the filtrate the sucrose is hydrolyzed in a specified manner.

7.2. Repetabilità

From the rotation of the filtrate before and after inversion, the sucrose content is calculated using the appropriate formulae.

Id-differenza fir-riżultati bejn iż-żewġ determinazzjonijiet imwettqa simultanjament jew f'segwenza mgħaġla fuq l-istess kampjun, mill-istess analista, taħt l-istess kondizzjonijiet, m'għandhiex teċċedi 0.2 g ta' xaħam għal kull 100 g tal-prodott bl-eċċezzjoni ta' trab ta' ħalib xkumat li għalieh id-differenza m'għandiex teċċedi 0.1 g xaħam għal kull 100 g tal-prodott.

4. REAGENTS

METODU 5: DETERMINAZZJONI TA' KONTENUT TA' SUCROSE

4.1. Zinc acetate solution, 1 M: dissolve 21,9 g crystallized zinc acetate dihydrate Zn(C2H.O2)2.2H2O and 3 ml glacial acetic acid in water and make up to 100 ml with water.

(metodu polarimetriku)

4.2. Potassium hexacyanoferrate (II) solution, 0,25 M: dissolve 10,6 g crystallized potassium hexacyanoferrate (II) trihydrate K4[Fe(CN)6]. 3H2O in water and make up to 100 ml with water.

1. SKOP U QASAM TA' APPLIKAZZJONI

4.3. Hydrochloric acid solution, 6,35 ± 0,20 M (20 to 22 %) or 5,0 ± 0,2 M (16 to 18 %).

Dan il-metodu jiddetermina l-kontenut ta' sucrose ta':

4.4. Ammonia solution, 2,0 ± 0,2 M (3,5 %).

- ħalib ikkondensat biz-zokkor,

4.5. Acetic acid solution, 2,0 ± 0,2 M (12 %).

- ħalib ikkondensat biz-zokkor parzjalment xkumat,

4.6. Bromothymol blue indicator, 1 % (m/v) solution in ethanol.

- ħalib ikkondensat biz-zokkor xkumat.

5. APPARATUS

Kampjuni m'għandhux ikun fihom zokkor invertit.

5.1. Balance, sensitivity 10 mg.

2. DEFINIZZJONI

5.2. Polarimeter tube, 2dm, of exactly calibrated length.

Il-kontenut ta' sucrose ta' ħalib ikkondensat biz-zokkor: il-kontenut ta' sucrose kif determint bil-metodu speċifikat.

5.3. Polarimeter or saccarimeter:

3. PRINĊIPJU

(a) Polarimeter with sodium light or mercury green light (mercury vapour lamp with prism or the special Wratten Screen No 77 A), to be read with an accuracy of at least 0.05 angular degrees,

Il-metodu huwa bbażat fuq il-prinċipju ta' l-inverżjoni clerget, trattament ħafif tal-kampjun b'aċidu li jipproduċi idrolisis sħieħa ta' sucrose imma kważi l-ebda lactose jew zokkor ieħor. Il-kontenut tas-sucrose huwa akkwistat mil kambjament fil-qawwa rotanti tas-soluzzjoni.

(b) Saccarimeter with international sugar scale, using white light passing through a filter of 15 mm of a 6 % solution of potassium bichromate, or sodium light, to be read with an accuracy of at least 0,1o on the international sugar scale.

Filtrat ċar tal-kampjun, mingħajr mutarotazzjoni b'lactose, huwa ppreparat bi trattament tas-soluzzjoni b'ammonja segwit b'newtralizazzjoni u tindif taż-żieda suċċessiva ta' soluzzjonijiet ta' aċetat taż-żingu u hexacyanoferrate tal-potassju ii.

5.4. Water bath, regulated at 60 oC ± 1 oC.

F'porzjon tal-filtrat tas-sucrose huwa idroliżżat f'manjiera speċifikata.

6. PROCEDURE

Mir-rotazzjoni tal-filtrat qabel u wara l-inverżjoni, il-kontenut tas-sucrose huwa kkalkolat bl-użu ta' formoli xierqa.

6.1. Control determination

4. REAĠENTI

In order to standardize the procedure, reagents and apparatus, carry out a control determination in duplicate as described below using a mixture of 100 g of milk and 18 g pure sucrose or a mixture of 110 g of skimmed milk and 18 g pure sucrose, each corresponding to 40 g of condensed milk containing 45 % sucrose. Calculate the sugar content using the formulae under 7, substituting for M, F and P respectively in formula 1 the quantity of milk taken and the fat and protein content of this milk, and in formula 2 for M, the value of 40,00. The mean of the values found shall not differ by more than 0,2 % from 45,0 %.

4.1. Soluzzjoni ta' aċetat taż-żingu, 1 m: ħoll 21.9 g ta' aċetat diħadrat taż-żingu kristalizzat ZN (C2H302)2.2O u 3 ml aċidu aċetiku glaċjali fl-ilma u għamel sa 100 ml bl-ilma.

6.2. Determination

4.2. Soluzzjoni ta' hexacyanoferrate tal-putassa (ii), 0.25 m: ħoll 10.6 g ta' hexacyanoferrate tal-putassa kristaliżżata (ii) trihydrate K4(FE(CN)6).3H2O f'ilma u għamel sa 100 ml bl-ilma.

6.2.1. Weigh to within 10 mg, approximately 40 g of the well mixed sample into a 100 ml glass beaker. Add 50 ml of hot water (80 to 90 oC) and mix well.

4.3. Soluzzjoni ta' aċidu idrokloriku, 6.35 aktar jew anqas 0.20 m (20 sa 22 %) jew 5.o aktar jew anqas 0.2 m (16 sa 18 %).

6.2.2. Transfer the mixture quantitatively to a 200 ml measuring flask, rinsing the beaker with successive quantities of water at 60 oC, until the total volume is between 120 and 150 ml. Mix and cool to room temperature.

4.4. Soluzzjoni ta' l-ammonja, 2.0 aktar jew anqas 0.2 m (3.5 %).

6.2.3. Add 5 ml of the dilute ammonia solution (4.4). Mix again and then allow to stand for 15 minutes.

4.5. Soluzzjoni ta' aċidu aċetiku, 2.0 aktar jew anqas 0.2 m (12 %).

6.2.4. Neutralize the ammonia by adding an equivalent quantity of the diluted solution of acetic acid (4.5). Determine the exact number of ml beforehand by titration of the ammonia solution using bromothymol blue as indicator (4.6). Mix.

4.6. Indikatur bromothymol ikħal, 1 % (m/v) soluzzjoni fl-etanol.

6.2.5. Add, with gently mixing by rotating the tilted flask, 12.5 ml of zinc acetate solution (4.1).

5. APPARAT

6.2.6. Add 12.5 ml of potassium hexacyanoferrate (II) solution (4.2) in the same way as for the acetate solution.

5.1. Miżien, sensitivita 10 mg.

6.2.7. Bring the contents of the flask to 20 oC and make up to the 200 ml mark with water at 20 oC.

5.2. Tubu ta' polarimetru, 2dm, ta' tul eżattament kalibrat.

Note:

5.3. Polarimetru jew sakkarimetru:

During any of the stages so far described all additions of water or reagents should have been made in such manner as to avoid the formation of air bubbles, and with the same object in view, all mixing should have been carried out by rotation of the flask rather than by shaking. If air bubbles are found to be present before making up to 200 ml volume, their removal can be assisted by temporarily connecting the flask to a vacuum pump, and rotating the flask.

(a) polarimetru b'dawl ħafif tas-sodju jew dawl aħdar tal-merkurju (lampa tal-fwar tal-merkurju bi priżma jew wratten screen n 77 a speċjali), li għandu jinqara b'eżatezza għal mill-anqas 0.05 gradi angulari,

6.2.8. Close the flask with a dry stopper and mix thoroughly by vigorous shaking.

(b) sakkarimetru bi skala internazzjonali taz-zokkor, li juża dawl ħafif abjad li jgħaddi minn filtru ta' 15 mm ta' 6 % ta' soluzzjoni ta' bikromat tal-potassju jew dawl ħafif tas-sodju, li għandu jinqara b'eżatezza ta' mill-anqas 0.1 ° fuq l-iskala internazzjonali taz-zokkor.

6.2.9. Allow to stand for a few minutes and then filter through a dry filter paper, rejecting the first 25 ml of filtrate.

5.4. Banju ta' l-ilma, irregolat fi 60 °C aktar jew anqas 1 °C.

6.2.10. Direct polarization: determine the optical rotation of the filtrate at 20 oC ± 1 oC.

6. PROĊEDURA

6.2.11. Inversion: pipette 40 ml of the filtrate obtained above into a 50 ml volumetric flask. Add 6,0 ml of 6,35 M hydrochloric acid or 7,5 ml of 5,0 M hydrochloric acid (4.3).

6.1. Determinazzjoni tal-kontroll

Place the flask in a waterbath of 60 oC for 15 minutes, ensuring that the entire bulb of the flask has been immersed. Mix by a rotatory movement during the first five minutes, in which time the contents of the flask should have attained the temperature of the bath. Cool to 20 oC, and make up to volume with water at 20 oC. Mix and allow to stand for one hour at this temperature.

Sabiex tkun standardizzata l-proċedura, reaġenti u apparat, wettaq kontroll ta' determinazzjoni f'duplikat kif deskritt hawn taħt bl-użu ta' taħlita ta' 100 g ta' ħalib u 18 g sucrose pur jew taħlita ta' 110 g ta' ħalib xkumat u 18 g ta' sucrose pur, kull wieħed jikkorespondi għal 40 g ta' ħalib ikkondensat li jkun fih 45 % sucrose. Ikkalkola l-kontenut taz-zokkor bl-użu tal-formoli skond 7, tissostitwixxi għal m, f u p rispetivament fil-formula 1 il-kwantità ta' ħalib meħud u l-konteut ta' xaħam u proteini ta' dan il-ħalib, u fil-formula 2 għal m, il-valur ta' 40.00. Il-medja tal-valuri misjuba m'għandiex tiddifferixi b'aktar minn 0.2 % minn 45.0 %.

6.2.12. Invert polarization

6.2. Determinazzjoni

Determine the rotation of the inverted solution at 20 oC ± 0.2 oC. (However, if temperature T of the liquid in the polarization tube differs by more than 0.2 oC during the measurement, the temperature correction referred to under 7.2 must be applied.)

6.2.1. Iżen sa limitu ta' 10 mg, bejn wieħed u ieħor 40 g tal-kampjun imħawwad sewwa f'vażett tal-ħġieġ ta' 100 ml. Żid 59 ml ta' ilma sħun (80 sa 90 °C) u ħawwad sewwa.

7. EXPRESSION OF RESULTS

6.2.2. Ittrasferixxi t-taħlita b'mod kwantitativ lejn kunjett tal-kejt ta' 200 ml, laħlaħ il-vażett bi kwantitajiet suċesivi ta' ilma fi 60 °C, sakemm il-volum kollu jkun bejn 129 u 150 ml. Ħallat u kessaħ lejn it-temperatura tal-kamra.

7.1. Method of calculation

6.2.3. Żid 5 ml ta' soluzzjoni ta' taħlita ta' l-ammonja (4.4). Ħallat għal darba oħra u imbagħad ħalli jogħod għal 15-il minuta.

Calculate the sucrose content by means of the following formulae:

6.2.4. Innewtralizza l-ammonja biż-żieda ta' kwantità ekwivalenti tas-soluzzjoni mħallta ta' aċidu aċetiku (4.5). Iddetermina n-numru eżatt ta' ml bil-quddiem bit-titrazzjoni tas-soluzzjoni ta' l-ammonja bl-użu ta' bromothymol ikħal bħala indikatur (4.6). Ħallat.

(1) v = M1001,08F + 1,55P

6.2.5. Żid, billi tħawwad ħafif f'rotazzjoni il-kunjett immejjel, 12.5 ml ta' soluzzjoni ta' aċetat taż-żingu (4.1).

(2) ×

6.2.6. Żid 12.5 ml ta' soluzzjoni ta' hexacyanoferrate tal-potassju (ii) (4.2) bl-istess mod bħas-soluzzjoni ta' l-aċetat.

6.2.7. Wassal il-kontenut tal-kunjett lejn 20 °C u għamel għall-marka ta' 200 ml bl-ilma fi 20 °C.

Nota:

where:

Matul xi stadji diġa deskritti ż-żidiet kollha ta' ilma jew reaġenti għandhom ikunu saru b'tali mod hekk li jevitaw il-formazzjoni ta' bżieżaq ta' l-arja, bl-istess għan, it-taħlit kollu kellu jkun twettaq b'dawrien tal-kunjett pjutost milli bit-taħwid. Jekk bżieżaq ta' l-arja jinstabu li jkunu preżenti qabel ma jitwassal għal volum ta' 200 ml, it-tneħħija tagħhom tista' tkun megħjuna b'konnessjoni temporanja tal-kunjett ma' pompa tal-vakum, u d-dawrien tal-kunjett.

S = sucrose content;

6.2.8. Agħlaq il-kunjett b'tapp xott u ħallat sewwa b'taħwid qawwi.

M = mass of the weighed sample in grams;

6.2.9. Ħalli joqgħod għal ftit minuti u imbagħad iffiltra minn karta tal-filtru niexfa, warrab l-ewwel 25 ml tal-filtrat.

F = percentage of fat in the sample;

6.2.10. Polariżazzjoni diretta: iddetermina r-rotazzjoni ottika tal-filtrat fi 20 °C aktar jew anqas 1 °C.

P = percentage Of protein (N x 6.38) in the sample;

6.2.11. Inverżjoni: ħu b'pipetta 40 ml tal-filtrat akkwistat hawn fuq ġewwa kunjett volumetriku ta' 50 ml. Żid 6.0 ml ta' 6.35 m aċidu idrokloriku jew 7.5 ml ta' 5.0 aċidu idrokloriku (4.3).

V = volume in ml to which the sample is diluted before filtration;

Qiegħed il-kunjett f'banju ta' l-ilma ta' 60 °C għal 15-il minuta, żgura li l-bozza kollha tal-kunjett tkun ġiet imdaħħla fil-likwidu. Ħallat b'moviment rotanti matul l-ewwel ħames minuti, li fihom il-kontenuti tal-kunjett għandhom ikunu laħqu t-temperatura tal-banju. Kessaħ għal 20 °C, u żid il-volum bl-ilma għal 20 °C. Ħawwad u ħalli joqgħod għal siegħa waħda f'din it-temperatura.

v = correction in ml for the volume of the precipitate formed during clarification;

6.2.12. Polariżazzjoni nvertita

D = direct polarimeter reading (polarization before inversion);

Iddetermina r-rotazzjoni tas-soluzzjoni nvertita fi 20 °C aktar jew anqas 0.2 °C. (madanakollu, jekk it-temperatura t tal-likwidu fit-tubu ta' polariżazzjoni tiddifferixxi b'aktar minn 0.2 °C matul il-kejl, il-korrezzjoni tat-temperatura li hemm referenza għaliha taħt 7.7 għandha tkun applikata.)

I = polarimeter reading after inversion;

7. ESPRESSJONI TAR-RIŻULTATI

L = length in dm of the polarimeter tube;

7.1. Metodu ta' kalkolazzjoni

Q = inversion factor, the values of which are given below.

bla

Remarks:

1) v =

(a) When exactly 40,00 g of condensed milk are weighed and a polarimeter with sodium light, angular degrees and a 2dm polarimeter tube at 20,0 oC ± 0,1 oC is used the sucrose content of normal condensed milk (C = 9) can be calculated from the following formula:

M1001.08 F +1.55 P

S = (D — 1,25 I) x (2,833 — 0,00612 F — 0,00878 P)

2) S =

(b) If the invert polarization is measured at a temperature other than 20 oC, the figures should be multiplied by:

(1 + 0,0037 (T — 20).

7.2. Values of the inversion factor Q

The following formulae give accurate values for Q, for various sources of light with corrections for concentration and temperature:

Fejn:

Sodium light and polarimeter with angular degrees:

S = il-kontenut tas-sukrosi;

Q = 0,8825 + 0,0006 (C — 9) — 0,0033 (T — 20).

M = il-massa tal-kampjun ippeżat fi grammi;

Mercury green light and polarimeter with angular degrees:

F = il-perċentwal tax-xaħam fil-kampjun;

Q = 1,0392 + 0,0007 (C — 9) — 0,0039 (T — 20).

P. = il-perċentwal cif tal-proteina (n x 6.38) fil-kampjun;

White light with dichromate filter and saccharimeter with international sugar scale degrees:

V = il-volum f'ml li miegħu il-kampjun jiġi dilwit qabel il-filtrazzjoni;

Q = 2,549 + 0,0017 (C — 9) — 0,0095 (T — 20).

v = il-korrezzjoni f'ml għall-volum tal-preċipitat iffurmat matul il-kjarifika;

In the above formulae:

D = il-qari dirett tal-polarimetru (il-polarizzazzjoni qabel l-inverżjoni);

C = Percentage of total sugars in the inverted solution as polarized,

I = il-qari tal-polarimetru wara l-inverżjoni;

T = Temperature of the inverted solution in the polarimetric reading.

L = it-tul f'dem tat-tubu tal-polarimetru;

Note 1:

Q = il-fattur ta' l-inverżjoni, li l-valuri tiegħu huma mogħtija hawn taħt.

The percentage of total sugars C in the inverted solution may be calculated from the direct reading and the change on inversion in the usual manner, using the usual values for the specific rotations of sucrose, lactose and invert sugar.

Rimarki:

The correction 0,0006 (C — 9) etc., is only accurate when C is approximately 9; for normal condensed milk, this correction can be neglected, C being close to 9.

(a) meta eżattament 40.00 g tal-ħalib ikkondensat jiġu miżuna u polarimetru bid-dawl tas-sodju, gradi angolari u tubu tal-polarimetru ta' 2dm f'temperatura ta' 20.0 °C ± 0.1 °C jiġi wżat, il-kontenut tas-sukrosi fil-ħalib ikkondensat normali (c = 9) jista' jiġi kkalkolat mill-formola li ġejja:

Note 2:

S =

Variation in temperature from 20 oC of 1 oC makes little difference in the direct reading, but variation of over 0,2 oC in the invert reading necessitates a correction. The correction - 0,0033 (T — 20) etc., is only accurate between 18 oC and 22 oC.

7.3. Repeatability

2.833 - 0.00612 F - 0.00878 P

The difference between results of two determinations carried out simultaneously or in rapid succession on the same sample, by the same analyst, under the same conditions, shall not exceed 0,3 g of sucrose per 100 g of condensed milk.

(b) jekk il-polarizzazzjoni inverta tiġi mkejla f'temperatura oħra għajr ta' 20 °C, iċ-ċifri ma għandhomx jiġu mmoltiplikati bi:

METHOD 6: DETERMINATION OF LACTIC ACID AND LACTATES CONTENT

(1 + 0.0037

1. SCOPE AND FIELD OF APPLICATION

This method determines the lactic acid and lactates, expressed as lactic acid, contents of:

7.2. Valuri ta' inverżjoni fattur q

- dried high fat milk or high fat milk powder,

Il-formoli li ġejjin jgħatu valuri eżatti għal q, għal diversi sorsi ta' dawl b'korrezzjonijiet ta konċentrazzjoni u temperatura:

- dried whole milk or whole milk powder,

Dawl tad-sodju u polarimetru bi gradi angulari:

- dried partly skimmed milk or partly skimmed-milk powder,

q = 0.8825 + 0.0006 (c - 9) - 0.0033 (t - 20).

- dried skimmed milk or skimmed-milk powder.

Dawl aħdar tal-merkurju u polarimetru bi gradi angulari:

2. DEFINITION

q = 1.0392 + 0.0007 (c - 9) - 0.0039 (t - 20).

Lactic acid and lactates content of dried milks: the lactic acid and lactates, expressed as lactic acid, contents as determined by the method specified.

Dawl abjad b'filtru dikromatiku u saccharimeter bi skali internazzjonali ta' gradi taz-zokkor:

3. PRINCIPLE

q = 2549 + 0.0017 (c - 9) - 0.0095 (t - 20).

Fat, protein and lactose are simultaneously removed from a solution of the sample by addition of copper sulphate and calcium hydroxide followed by filtration.

Fil-formoli ta' hawn fuq:

The lactic acid and lactates in the filtrate are converted into acetaldehyde by concentrated sulphuric acid in the presence of copper II sulphate.

C = persentaġġ taz-zokkor totali fis-soluzzjoni nvertita kif polariżżata,

The lactic acid content is determined colorimetrically using p-hydroxydiphenyl.

T = temperatura tas-soluzzjoni nvertita fil-qari polarimetriku.

The lactic acid and lactates content is expressed as mg of lactic acid per 100 g of solids-non-fat.

Nota 1:

4. REAGENTS

Il-persentaġġ totali taz-zokkor c fis-soluzzjoni nvertita jista' jkun ikkalkolat mill-qari dirett u l-kambjament fuq l-inverżjoni fil-manjiera tas-soltu, bl-użu tal-valuri tas-soltu għal rotazjonijiet sepċifiċi ta' sucrose, lactose u zokkor invertit.

4.1. Copper (II) sulphate solution: dissolve 250 g of copper (II) sulphate (CuSO4.5H2O) in water and dilute to 1000 ml with water.

Il-korrezzjoni 0.0006 (c - 9) eċċ., hija biss eżatta meta c ikun approssimament 9; għall-ħalib ikkondensat normali, din il-korrezzjoni tista' tkun injorata, c jkun qrib ta' 9.

4.2. Calcium hydroxide suspension.

Nota 2:

4.2.1. Grind 300 g of calcium hydroxide (Ca(OH)2) in a mortar with water, using totally 900 ml. The suspension should be freshly prepared before use.

Varjazzjoni fit-temperatura minn 20 °C ta' 1 °C tagħmel ftit differenza fil-qari dirett, imma varjazzjoni ta' aktar minn 0.2 °C fil-qari nvertit teħtieġ korrezzjoni. Il-korrezzjoni - 0.0033 (t - 20) eċċ., hija biss eżatta bejn 18 °C u 22 °C.

4.2.2. Calcium hydroxide suspension: grind 300 g of calcium hydroxide (Ca(OH)2) in a mortar with water, using totally 1400 ml. The suspension should be freshly prepared before use.

7.3. Repetabilità

4.3. Sulphuric acid — copper (II) sulphate solution: Add to 300 ml of sulphuric acid, 95,9 to 97,0 % (m/m) of H2SO4, 0,5 ml of the copper (II) sulphate solution (4.1).

Id-differenza fir-riżultati bejn żewġ determinazzjonijiet imwettqa simultanjament jew f'sekwenza mgħaġla fuq l-istess kampjun, mill-istess analista, taħt l-istess kondizzjonijiet, m'għandhiex teċċedi 0.3 g ta' sucrose għal kull 100 g ta' ħalib ikkondensat.

4.4. p-hydroxydiphenyl (C6H5C6H4OH) solution: dissolve, by shaking and by heating slightly 0,75 g of p-hydroxydiphenyl in 5 ml of an aqueous solution of sodium hydroxide, containing 5 g of NaOH per 100 ml. Dilute to 50 ml with water in a volumetric flask. Keep the solution in a brown coloured glass bottle in a dark and cool place. Do not use if the colour changes or tubidity occurs. The maximum shelf life is 72 hours.

METODU 6: DETERMINAZZJONI TA' AĊIDU LAKTIKU U LAKTATI FIL-KONTENUT

4.5. Lactic acid standard solution: dissolve, shortly before use, 0,1067 g of lithium lactate (CH3 CHOHCOOLi) in water and dilute to 1000 ml in a volumetric flask. 1 ml of this solution corresponds to 0,1 mg of lactic acid.

1. SKOP U QASAM TA' APPLIKAZZJONI

4.6. Standard reconstituted milk: analyse in advance several samples of high quality dried milk. For the preparation of the calibration curve select the sample having the lowest lactic acid content, containing not more than 30 mg of lactic acid per 100 g of solids-non-fat. Follow the operating procedure described under 6.2.1 and 6.2.2 below.

Dan il-metodu jiddetermina l-aċidu laktiku u laktati, espressi bħala aċidu laktiku, kontenuti ta':

5. APPARATUS

- ħalib niexef b'xaħam għoli jew trab tal-ħalib b'xaħam għoli,

5.1. Analytical balance.

- ħalib komplut niexef jew trab ta' ħalib komplut,

5.2. Spectrophotometer suitable for readings at a wavelength of 570 nm.

- ħalib niexef parzjalment xkumat jew trab ta' ħalib parzjalment xkumat,

5.3. Waterbath at 30 oC ± 2 oC.

- ħalib niexef xkumat jew trab ta' ħalib xkumat.

5.4. Mortar and pestle.

2. DEFINIZZJONI

5.5. Filter paper (Schleicher and Schull 595, Whatman 1 or equivalent).

Kontenut ta' aċidu laktiku u laktati ta' ħalib niexef: l-aċidu laktiku u laktati, espressi bħala aċidu laktiku, kontenuti kif determinati mil-metodu speċifikat.

5.6. Test tubes, pyrex or equivalent (dimensions 25 x 150 mm).

3. PRINĊIPJU

Note:

Xaħam, proteina u lactose huma simultanjament imneħħija minn soluzzjoni tal-kampjun b'żieda ta' sulfat tar-ramm u idrossidu tal-ġir segwit b'filtrazzjoni.

All glassware must be perfectly clean and designated for use solely in this determination. Rinse glassware containing precipitate residues with concentrated hydrochloric acid before washing.

L-aċidu laktiku u l-laktati fil-filtrat huma kkonvertiti fi acetaldehyde b'aċidu sulforiku kkonċentrat fil-preżenza ta' kubrit tar-ramm ii.

6. PROCEDURE

Il-kontenut ta' aċidu laktiku huwa ddetterminat kulurmetrikalment bl-użu ta' p- hydroxydiphenyl.

6.1. Blank test

Il-kontenut ta' l-aċidu laktiku u laktati huwa espress bħala mg ta' aċidu laktiku għal kull 100 g ta' solidi mingħajrxaħam.

Carry out a blank test by placing 30 ml of water into a 50 ml graduated tube and treating this tube as described under 6.2.4 to 6.2.11 inclusive. If the blank measured against water exceeds an equivalent of 20 mg of lactic acid per 100 g solids-non-fat, the reagents should be checked and the impure reagents or reagent should be replaced. Carry out the blank test at the same time as the analysis of the sample.

4. REAĠENTI

6.2. Determination

4.1. Soluzzjoni tas-sulfat tar-ramm (ii): ħoll 250 g ta' sulfat tar-ramm (ii) (CuSO4.5H2O) fl-ilma u dewweb għal 1000 ml bl-ilma.

Note: Avoid contamination with impurities especially with saliva and sweat.

4.2. Sospenzjoni ta' idrossidu tal-kalċju.

6.2.1. Determine the solids-non-fat content (a) g of the sample by subtracting the fat content (obtained by method 4) and the moisture content (obtained by method 2) from 100.

4.2.1. Itħan 300 g ta' idrossidu tal-kalċju (Ca(OH)2) f'mehrież bl-ilma, tuża b'kollox 900 ml. Is-sospensjoni għandha tkun ippreparata friska qabel l-użu.

6.2.2. Weigh 1000a-10g of the sample to the nearest 0,1 g. Add this quantity of sample to 100 ml of

4.2.2. Sospensjoni ta' idrossidu tal-kalċju: itħan 30 g ta' idrossidu tal-kalċju (Ca(OH)2) f'mehrież bl-ilma, tuża b'kollox 1400 ml. Is-sospensjoni għandha tkun ippreparata friska qabel l-użu.

6.2.3. Pipette 5 ml of the solution obtained into a 50 ml graduated tube and dilute with water to about 30 ml.

4.3. Soluzzjoni ta' sulfat ta' aċidu sulforiku tar-ramm (ii): żid ma 300 ml ta' aċidu sulforiku, 95,9 sa 97.0 % (m/m) ta' H2SO4, 0.5 ml tas-soluzzjoni ta' sulfat tar-ramm (ii) (4.1).

6.2.4. Add slowly while shaking, 5 ml of the copper (II) sulphate solution (4.1) and allow to stand for 10 minutes.

4.4. Soluzzjoni p-hydroxydiphenyl (C6H5C6H4OH): ħoll, billi tħawwad u ssaħan ħafif 0.75 g ta' p-hydroxydiphenyl fi 5 ml ta' soluzzjoni akweja ta' idrossidu tas-sodju, li jkun fih 5 g ta NaOH għal kull 100 ml. Dewweb għal 50 ml bl-ilma f'kunjett volumetriku. Żomm is-soluzzjoni fi flixkun tal-ħġieġ ta' lewn kannella f'post mudlam u kiesaħ. Tużahx jekk ikun hemm kambjament tal-kulur jew isseħħ tubidità. Il-ħajja massima ta' fuq l-ixkaffa hija ta' 72 siegħa.

6.2.5. Add slowly while shaking, 5 ml of the calcium hydroxide suspension (4.2.1) or 10 ml of the calcium hydroxide suspension (4.2.2).

4.5. Soluzzjoni standard ta' aċidu laktiku: ħoll, ftit qabel l-użu, 0.1067 g ta' laktat tal-litjum (CH3CHOHCOOLi) fl-ilma u dewweb għal 1000 ml f'kunjett volumtriku. 1 ml ta' din is-soluzzjoni jikkorrespondi għal 0.1 mg ta' aċidu laktiku.

6.2.6. Dilute to 50 ml with water, shake vigorously, allow to stand for 10 minutes then filter. Discard the first runnings.

4.6. Ħalib normali rikostitwit: analizza bil-quddiem diversi kampjuni ta' ħalib niexef ta' kwalità għolja. Għall-preparazzjoni tal-kurva tal-kalibrazzjoni agħżel il-kampjun li jkollu l-anqas kontenut ta' aċidu laktiku, li jkun fih mhux aktar minn 30 mg ta' aċidu laktiku għal kull 100 g ta' solidi – mingħajr-xaħam. Segwi l-proċedura ta' l-operazzjoni kif deskritta fil-6.2.1 u 6.2.2 hawn taħt.

6.2.7. Pipette 1 ml of the filtrate into a test tube (5.6).

5. APPARAT

6.2.8. Add to the tube by means of a burette or graduated pipette 6.0 ml of the sulphuric acid-copper (II) sulphate solution (4.3). Mix.

5.1. Miżien analitiku.

6.2.9. Heat in the boiling water bath for five minutes. Cool to ambient temperature under running water.

5.2. Spektrofotometru addattat għal qari f'wavelength ta' 570 nm.

6.2.10. Add two drops of p-hydroxydiphenyl reagent (4.4) and shake vigorously to spread the reagent evenly throughout the liquid. Place the tube in the waterbath at 30 oC ± 2 oC; leave for 15 minutes shaking from time to time.

5.3. Banju ta' l-ilma fi 30 °C aktar jew anqas 2 °C.

6.2.11. Place the tube in the boiling waterbath for 90 seconds. Cool to ambient temperature under running water.

5.4. Mehrież u lida.

6.2.12. Measure the optical density against the blank test (6.1) within three hours at the wavelength specified under 5.2.

5.5. Karta tal-filtru (schleicher u schull 595, whatman 1 jew ekwivalenti).

6.2.13. If the optical density exceeds that of the highest point of the standard curve, repeat the test using an adequate dilution of the filtrate obtained under 6.2.6.

5.6. Tubi tat-testijiet, pyrex jew ekwivalenti (dimenzjonijiet 25 bi 150 mm).

6.3. Preparation of the standard

Nota:

6.3.1. Pipette 5 ml of the reconstituted milk (4.6) into five 50 ml graduated tubes. Pipette into these tubes 0, 1, 2, 3 and 4 ml respectively of the standard solution (4.5), so as to obtain a range of standards corresponding to 0, 20, 40, 60 and 80 mg of added lactic acid per 100 g of solids-non-fat, of the dried milk.

L-apparat kollu tal-ħġieġ irid ikun perfettament nadif u intenzjonat għall-użu waħdieni f'din id-determinazzjoni. Laħlaħ l-apparat tal-ħġieġ li jkun fih residwi preċipitanti b'aċidu idrokloriku kkonċentrat qabel il-ħasil.

6.3.2. Dilute with water to about 30 ml and treat as described under 6.2.4 to 6.2.11.

6. PROĊEDURA

6.3.3. Measure the optical densities of the standards (6.3.1) against the blank test (6.1) at the wavelength specified under 5.2. Plot in a diagram the optical densities against the quantities of lactic acid given under 6.3.1, i.e. 0 mg, 20 mg, 40 mg, 60 mg and 80 mg per 100 g of solids-non-fat. Draw the best fitting straight line through the points and prepare the standard curve by moving this line parallel to itself in such a way that it passes through the origin.

6.1. Test vġut

7. EXPRESSION OF RESULTS

Wettaq test vġut billi tqiegħed 30 ml ta' ilma f'tubu ta' gradwazzjoni ta' 50 ml u ttratta dan it-tubu kif deskritt taħt 6.2.4 sa 6.2.11 inklussivi. Jekk il-vġut imkejjel kontra l-ilma jeċċedi l-ekwivalenti ta' 20 mg ta' aċidu laktiku għal kull 100 g ta' solidi – mingħajr-xaħam, ir-reaġenti għandhom ikunu ivverifikati u r-reaġenti mhux puri jew reaġenti għandhom ikunu mibdula. Wettaq it-test vġut fl-istess waqt ta' l-analiżi tal-kampjun.

7.1. Method of calculation

6.2. Determinazzjoni

Convert the optical density measured under 6.2.12 or 6.2.13 into mg of lactic acid per 100 g of solids-non-fat in the sample by reference to the standard curve. Multiply this result by the dilution factor where the filtrate has been diluted according to 6.2.13.

Nota:

7.2. Repeatability

evita kontaminazzjoni b'impuritajiet speċjalment bil-bżieq u l-għaraq.

The difference between the results of two determinations carried out simultaneously or in rapid succession on the same sample, by the same analyst, under the same conditions, shall not exceed 8 mg of lactic acid per 100 g of solids-non-fat for contents up to 80 mg. For higher values, this difference may not exceed 10 % of the lowest value.

6.2.1. Iddetermina l-kontenut tas-solidi-mingħajr-xaħam (a) g tal-kampjun bit-tnaqqis tal-kontenut tax-xaħam (akkwistat b'metodu 4) u l-kontenut ta' umdità (a2kwistat b'metodu 2) minn 100.

METHOD 7: DETERMINATION OF PHOSPHATASE ACTIVITY (MODIFIED SANDERS AND SAGER PROCEDURE)

6.2.2. Iżen

1. SCOPE AND FIELD OF APPLICATION

This method describes the determination of phosphatase activity in:

tal-kampjun lejn l-eqreb 0.1 g. Żid din il-kwantità tal-kampjun (a - 10) ma 100 ml ta' ilma u ħallat sewwa

- dried high fat milk or high fat milk powder,

6.2.3. Bil-pipetta għaddi 5 ml tas-soluzzjoni akkwistata f'tubigradwatii ta' 50 ml u dewweb bl-ilma għal madwar 30 ml.

- dried whole milk or whole milk powder,

6.2.4. Żid bil-mod waqt li tħawwad, 5 ml tas-soluzzjoni tas-sulfat tar-ramm (ii) (4.1) u ħalli joqgħod għal 10 minuti.

- dried partly skimmed milk or partly skimmed-milk powder,

6.2.5. Żid bil-mod waqt li tħawwad, 5 ml ta' sospensjoni ta' l-idrossidu tal-kalċju (4.2.1) jew 10 ml tas-sospensjoni ta' l-idrossidu tal-kalċju (4.2.2).

- dried skimmed milk or skimmed-milk powder.

6.2.6. Dewweb għal 50 ml bl-ilma, ħawwad bil-qawwa, ħalli joqgħod għal 10 minuti u mbagħad iffiltra. Warrab l-ewwel ħasil.

2. DEFINITION

6.2.7. Bil-pipetta qiegħed 1 ml tal-filtrat f'tubu tat-testijiet (5.6).

The phosphatase activity of dried milks is a measure of the quantity of active alkaline phosphatase present. It is expressed as the quantity of phenol in μg liberated by 1 ml of reconstituted milk, as determined by the procedure described below.

6.2.8. Żid mat-tubu permezz ta' buretta jew pipetta gradwata, 6.0 ml tas-soluzzjoni tas-sulfat ta' l-aċdu ta-ramm sulfuriku (ii) (4.3). Ħallat.

3. PRINCIPLE

6.2.9. Saħħan fil-banju bl-ilma jgħali għal ħames minuti. Kessaħ lejn it-temperatura ta' l-ambjent taħt ilma ġieri.

The phosphatase activity of dried milks is determined by the ability of the phosphatase to liberate the phenol from disodiumphenylphosphate. The quantity of phenol liberated under prescribed conditions is determined by a spectrophotometric measurement of the colour developed with Gibb's reagent.

6.2.10. Żid żewġ taqtiriet ta' reaġent p-hydroxydiphenyl (4.4) u ħawwad bil-qawwa biex jinxtered ir-reaġent matul il-likwidu kollu. Qiegħed it-tubu fil-banju ta' l-ilma fi 30 °C aktar jew anqas 2 °C; ħalli joqgħod għal 15-il minuta tħawwad minn ħin għall-ieħor.

4. REAGENTS

6.2.11. Qiegħed it-tubu fil-banju ta' l-ilma jgħali għal 90 sekonda. Kessaħ lejn it-temperatura ta' l-ambjent taħt ilma ġieri.

4.1. Solution A

6.2.12. Kejjel id-densità ottika kontra t-test vġut (6.1) fi żmien tliet siegħat fil-wavelength speċifikata fi 5.2.

Barium borate hydroxide buffer: pH 10,6 ± 0,1 at 20 o C.

6.2.13. Jekk id-densità ottika teċċedi dik ta' l-għola punt tal-kurva normali, irrepeti t-test billi tuża tidwib adegwat tal-filtrat akkwistat permezz ta' 6.2.6.

Dissolve: 25,0 g of barium hydroxide (Ba(OH)2.8H2O) in water and dilute to 500 ml.

6.3. Preparazzjoni ta' l-istandard

Dissolve: 11,0 g of boric acid (H3BO3) in water and dilute to 500 ml.

6.3.1. Bil-pipetta qiegħed 5 ml tal-ħalib rikostitwit (4.6) f'ħames tubi gradwati ta' 50 ml. Bil-pipetta itfa' f'dawn it-tubi 0, 1, 2, 3 u 4 ml rispettivament tas-soluzzjoni standard (4.5), hekk li takkwista medda ta' standards korrispondenti għal 0, 20, 40,60 u 80 mg ta' aċidu laktiku miżjud għal kull 100 g ta' solidi mingħajr xaħam, tal-ħalib niexef.

Warm the two solutions to 50 o C and mix.

6.3.2. Dewweb bl-ilma għal madwar 30 ml u ttratta kif deskritt fi 6.2.4 sa 6.2.11.

Shake and cool the mixture to room temperature.

6.3.3. Kejjel id-densità ottika ta' l-istandards (6.3.1) kontra t-test vġut (6.1) fil-wavelength speċifikat fi 5.2. Immarka f'dijagramma d-densitajiet ottiċi kontra l-kwantitajiet ta' aċidu laktiku kif mogħti fi 6.3.1, i.e. o mg, 20 mg, 40 mg, 60 mg u 80 mg għal kull 100 g ta' solidi mingħajr xaħam. Pinġi l-aħjar linja dritta li toqgħod matul il-punti u pprepara il-kurva standard billi ċċaqlaq din il-linja paralella fiha nnifisha b'tali mod hekk li tgħaddi mill-oriġinu.

Adjust the pH to 10,6 ± 0,1 with the barium hydroxide solution and filter.

7. ESPRESSJONI TAR-RIŻULTATI

Store the solution in a tightly stoppered container.

7.1. Metodu ta' kalkolazzjoni

Before use, dilute the buffer with an equal quantity of water.

Ikkonverti d-densità ottika mkejla permezz ta' 6.2.12 jew 6.2.13 fi mg ta' aċidu laktiku għal kull 100 g ta' solidi mingħajr xaħam fil-kampjun b'referenza għall-kurva standard. Immoltiplika dan ir-riżultat bil-fattur tat-tidwib meta l-filtrat ikun ġie mdewweb skond 6.2.13.

4.2. Solution B:

7.2. Repetabilità

Colour development buffer.

Id-differenza bejn ir-riżultati taż-żewġ determinazzjonijiet imwettqa simultanjament jew f'segwenza mgħaġla fuq l-istess kampjun, mill-istess analista, taħt l-istess kondizzjonijiet, m'għandhiex teċċedi 8 mg ta' aċidu laktiku għal kull 100 g ta' solidi mingħajr xaħam għal kontenut ta' mhux aktar minn 80 g għal valuri għola, din id-differenza ma tistax teċċedi 10 % tal-valur l-aktar baxx.

Dissolve: 6,0 g of sodium metaborate (NaBO2) (or 12,6 g of NaBO2.4H2O) and 20,0 g of sodium chloride (NaCl) in water and dilute to 1000 ml with water.

METODU 7: DETERMINAZZJONI TA' L-ATTIVITÀ FOSFATAŻI

4.3. Solution C

(PROĊEDURA MMOFIDIKATA SANDERS U SAGER)

Buffer substrate solution.

1. SKOP U QASAM TA' APPLIKAZZJONI

4.3.1. Dissolve 0,5 g of disodiumphenylphosphate (Na2C6H5PO4.2H2O) in 4,5 ml of Solution B (4.2). Add 2 drops of Solution E (4.5) and allow to stand 30 minutes. Extract the colour with 2,5 ml butanol (4.10). If necessary, repeat the colour extraction. After separation, discard the butanol. This solution can be kept for several days in a refrigerator. Develop and extract the colour once more before use.

Dan il-metodu jiddeskrivi d-determinazzjoni ta' l-attività fosfatażi fi:

4.3.2. Pipette 1 ml of this solution into a 100 ml volumetric flask and make up to volume with Solution A. Prepare the buffer solution immediately before use.

- ħalib niexef b'xaħam għoli jew trab tal-ħalib b'xaħam għoli,

4.4. Solution D

- ħalib komplut niexef jew trab ta' ħalib komplut,

Precipitant.

- ħalib niexef parzjalment xkumat jew trab ta' ħalib parzjalment xkumat,

Dissolve 3,0 g of zinc sulphate (ZnSO4.7H2O) and 0,6 g of copper (II) sulphate (CUSO4.5H2O) in water and make up to 100 ml with water.

- ħalib niexef xkumat jew trab ta' ħalib xkumat.

4.5. Solution E

2. DEFINIZZJONI

Gibb's reagent.

L-attività fosfatażi ta' ħalib niexef hija miżura tal-kwantità ta' fosfatażi alkalina attiva preżenti. Din hija espressa bħala l-kwantità ta' fenol fi μg illiberata bi 1 ml ta' ħalib rikostitwit, kif determinat bil-proċedura deskritta hawn taħt.

Dissolve 0,040 g of 2,6-dibromoquinone 1,4 — chloroimide (O.C6H2Br2.NCl) in 10 ml of 96 % ethanol. Store the solution in a dark glass bottle kept in a refrigerator. Discard this reagent when it has become discoloured.

3. PRINĊIPJU

4.6. Colour dilution buffer

L-attività fosfatażi ta' ħalib niexef hija ddeterminata bil-kapaċità tal-fosftażi li tillibera l-fenol middisodiumphenylphosphate. Il-kwantità ta' fenol illiberata permezz tal-kondizzjonijiet preskritti hija ddeterminata b'kejl spektrofotometriku tal-kulur żviluppat bil-gibb tar-reagent.

Dilute 10 ml of Solution B (4.2), colour development buffer, to 100 ml with water.

4. REAĠENTI

4.7. Copper sulphate solution

4.1. Soluzzjoni a

Dissolve 0,05 g of copper (II) sulphate (CUSO4.5H2O) in water and make to 100 ml with water.

Kuxxinett tal-barium borate hydroxide: ph 10.6 c aktar jew anqas 0.1 fi 20 c.

4.8. Phenol standard solution

Ħoll: 25.0 g ta' barium hydroxide (Ba(OH)2.8H2O) fl-ilma u dewweb sa 500 ml.

Dissolve 0,200 ± 0,001 g of pure phenol in water and make up to 100 ml in a volumetric flask with water. This solution can be stored for several months in a refrigerator. Dilute 10 ml of this solution to 100 ml with water. This diluted solution contains 200 μg of phenol in 1 ml and can be used for preparing more dilute solutions.

Ħoll: 11.0 g ta' aċidu boriku (h3bo3) fl-ilma u dewweb sa 500 ml.

4.9. Boiled distilled water.

Saħħan iż-żewġ soluzzjonijiet sa' 50 °C u ħawwad.

4.10. n-Butanol.

Ħawwad u kessaħ lejn it-temperatura tal-kamra.

5. APPARATUS

Aġġusta l-ph għal 10.6 aktar jew anqas 0.1 bis-soluzzjoni barium hydroxide u iffiltra.

5.1. Analytical balance.

Aħżen is-soluzzjoni f'kontenitur b'tapp li jagħlaq sewwa.

5.2. Waterbath, thermostatically controlled at 37 oC ± 1 oC.

Qabel l-użu, dewweb il-kuxxinett bi kwantità ugwali ta' ilma.

5.3. Spectrophotometer suitable for readings at a wavelength of 610 nm.

4.2. Soluzzjoni b:

5.4. Filter paper (Schleicher and Schull 597, Whatman 42 or equivalent filter paper).

Żvilupp tal-kuxxinett tal-kulur.

5.5. Waterbath, boiling.

Ħoll: 6.0 g ta' sodium metaborate (NaBO2) (jew 12.6 ta' NaBO2.4H2O) u 20.0 g ta' klorat tas-sodju (NaCl) fl-ilma u dewweb għal 1000 ml bl-ilma.

5.6. Aluminium foil.

4.3. Soluzzjoni c

6. PROCEDURE

Kuxxinett ta' soluzzjoni ta' substrate.

Precautions:

4.3.1. Ħoll 0.5 g ta' disodiumphenylphosphate (Na2C6H5PO4.2H2O) fi 4.5 ml ta' soluzzjoni b (4.2). Żid 2 taqtiriet ta' soluzzjoni e (4.5) u ħalli joqgħod għal 30 minuta. Estratta l-kulur bi 2.5 ml butanol (4.10). Jekk meħtieġ, irrepeti l-estrazzjoni tal-kulur. Wara s-separazzjoni, warrab il-butanol. Din is-soluzzjoni tista' tinżamm għal diversi jiem f'refriġerejter. Żviluppa u oħroġ il-kulur darba oħra qabel l-użu.

1. Avoid direct exposure to sunlight.

4.3.2. B'pipetta qiegħed 1 mg ta' din is-soluzzjoni f'kunjett volumetriku ta' 100 ml u imla l-volum b'soluzzjoni a. Ipprepara s-soluzzjoni tal-kuxxinett immedjatament qabel l-użu.

2. All the glassware, stoppers and removal material should be perfectly clean. It is recommended that they be rinsed and boiled with water or that they be treated with steam.

4.4. Soluzzjoni d

3. Avoid using plastic materials (stoppers for example) as they may contain phenols.

Preċipitant

4. Saliva contains phosphatase; contamination by traces of saliva must therefore be carefully avoided.

Ħoll 3.0 g ta' sulfat taż-żingu (ZnSO4.7H2O) u 0.6 g ta' sulfat tar-ramm (ii) (CuSO4.5H2O) fl-ilma u ħoll għal 100 ml bl-ilma.

6.1. Preparation of the sample

4.5. Soluzzjoni e

6.1.1. Weigh, to within 0.1 g, 10 g of the sample and dissolve in 90 ml of water. The temperature for dissolving the powder shall, under no circumstances, exceed 35 oC.

Il-gibb tar-reaġent

6.2. Determination

Ħoll 0 040 g ta' 2,6-dibromoquinone 1,4-chloroimide (O.C6H2Br2.NCl) fi 10 ml ta' 96 % etanol. Aħżen is-soluzzjoni fi flixkun tal-ħġieġ skur miżmum f'refriġerejter. Warrab dan ir-reaġent meta jkun tilef il-kulur.

6.2.1. Introduce in each of two test tubes 1 ml of reconstituted milk prepared as described in 6.1.1.

4.6. Kuxxinett ta' tidwib ta' kulur

6.2.2. Heat one of the tubes in boiling water for two minutes. Cover the tube and the waterbath (5.5) or, for example, a beaker with aluminium foil (5.6) to ensure that the entire tube will be heated. Cool in cold water to room temperature. Use this tube for the blank test. For all subsequent operations treat the two tubes identically.

Dewweb 10 ml ta' soluzzjoni b (4.2), kuxxinet ta żvilupp ta' kulur, ma 10 ml bl-ilma.

6.2.3. Add 10 ml of Solution C (4.3.2). Mix and place the tube in the waterbath at 37 oC (5.2).

4.7. Soluzzjoni tas-sulfat tar-ramm

6.2.4. Incubate for 60 minutes in the waterbath shaking periodically.

Dewweb 0.05 g ta' sulfat tar-ramm (ii) (CuSO4.5H2O) fl-ilma u wassal għal 100 ml bl-ilma.

6.2.5. Transfer the tubes immediately to a boiling waterbath (5.5) and heat for two minutes; cool to room temperature in cold water.

4.8. Soluzzjoni standard tal-fenol

6.2.6. Add 1 ml of Solution D (4.4), mix and filter through a dry filter paper; discard the first filtrates until a clear liquid is obtained.

Ħoll0 200 aktar jew anqas 0 001 g ta' fenol pur fl-ilma u wassal għal 10 ml f'kunjett volumetriku bl-ilma. Din is-soluzzjoni tista' tkun maħżuna għal diversi xhur f'refriġerejter. Dewweb 10 ml ta' din is-soluzzjoni ma 100 ml bl-ilma. Din is-soluzzjoni mdewwba fiha 200 μg ta' fenol fi 1 ml u tista' tkun użata għal preparazzjoni ta' soluzzjonijiet aktar imdewwba.

6.2.7. Put 5 ml of each filtrate into test tubes, add 5 ml of Solution B (4.2) and 0.1 ml of Solution E (4.5). Mix.

4.9. Ilma ddistillat mgħolli.

6.2.8. Allow the colour to develop at room temperature for 30 minutes away from direct sunlight.

4.10. N-butanol.

6.2.9. Measure the optical density of the sample solution, against the blank, at the wavelength indicated in 5.3.

5. APPARAT

6.2.10. Repeat the determination if the optical density of the solution is above that of the standard sample with 20 μg of phenol prepared according to 7.

5.1. Miżien analitiku.

If this limit is exceeded, dilute a suitable volume of reconstituted milk according to 6.1.1 with a suitable volume of this milk carefully boiled as indicated in 6.2.2 to inactivate the phosphatase present.

5.2. Banju ta' l-ilma, ikkontrollat termostatikament fi 37 °C aktar jew anqas 1 °C.

7. PREPARATION OF THE STANDARD CURVE

5.3. Spektrofotometru tajjeb għal qari f'wavelengths ta' 610 nm.

7.1. Pipette into four 100 ml volumetric flasks, 1, 3, 5 and 10 ml of the standard solution diluted according to 4.8 and make up to volume with water; these dilutions contain respectively 2, 6, 10 and 20 μg of phenol per ml.

5.4. Karta tal-filtru (schleicher u schull 597, whatman 42 jew karta tal-filtru ekwivalenti).

7.2. Pipette 1 ml of water or 1 ml of each standard solution (7.1) into the test tubes in order to obtain a series of samples containing 0 (blank value obtained using the 1 ml of water) — 2 — 6 — 10 and 20 μg of phenol.

5.5. Banju għat-tgħollija ta' l-ilma.

7.3. Pipette successively into each test tube 1 ml of the solution of copper (II) sulphate (4.7), 5 ml of the colour dilution buffer solution (4.6), 3 ml of water and 0.1 ml of Solution E (4.5). Mix.

5.6. Folja ta' l-aluminju.

7.4. Leave the test tubes for 30 minutes at room temperature away from direct sunlight.

6. PROĊEDURA

7.5. Measure the absorbance of the solutions in each of the tubes, compared to the blank value, at the wavelength indicated in 5.3.

Prekawzjonijiet:

7.6. Prepare the standard curve by plotting the absorbance values against the quantities of phenol in μg as indicated in 7.2.

1. Evita l-esposizzjoni diretta għad-dawl tax-xemx.

8. EXPRESSION OF THE RESULTS

2. L-apparat kollu tal-ħġieġ, tappini u materjal tat-tneħħija għandu jkun perfettament nadif. Huwa rrakkomandat li dawn ikunu mlaħalħa u mgħollija fl-ilma jew li jkunu trattati fil-fwar.

8.1. Calculation

3. Evita l-użu ta' materjali tal-plastik (per eżempju tappini) minħabba li dawn jista' jkun fihom il-fenoli.

8.1.1. Convert the figures as determined under 6.2.9 to μg of phenol, by reference to the standard curve.

4. Il-bżieq fih fosfatażi; kontaminazzjoni bi traċċi ta' bżieq għandhom għalhekk ikunu evitati bil-galbu.

8.1.2. Calculate the phosphatase activity expressed as μg of phenol per ml of reconstituted milk according to the following formula:

6.1. Preparazzjoni tal-kampjun

Phosphatase activity = 2,4 x P

6.1.1. Iżen, sa marġini ta' 0.1 g, 10 grammi tal-kampjun u ħoll fi 90 ml ta' ilma. It-temperatura għall-ħall tat-trab għandha, fi kwalunkwe ċirkostanza, teċċedi 35 °C.

where P = the quantity of phenol in μg according to 8.1.1.

6.2. Determinazzjoni

8.1.3. If it was necessary to dilute as indicated under 6.2.10 multiply the result obtained in 8.1.2 by the dilution factor.

6.2.1. Introduċi f'kull wieħed miż-żewġ tubi tat-testijiet 1 ml ta' ħalib rikonstitwit ippreparat kif deskritt fi 6.1.1.

8.2. Repeatability

6.2.2. Saħħan wieħed mit-tubi fl-ilma jagħli għal żewġ minuti. Għatti t-tubu u l-banju ta' l-ilma (5.5) jew, per eżempju, vażett b'folja ta' l-aluminju (5.6) biex tiżgura li t-tubu kollu jkun imsaħħan. Kessaħ f'ilma kiesaħ lejn it-temperatura tal-kamra. Uża dan it-tubu għat-test vġut. Għall-operazzjonijiet sussegwenti kollha, ittratta ż-żewġ tubi ugwalment.

The difference between the results of two determinations carried out simultaneously or in rapid succession on the same sample, by the same analyst, under the same conditions, shall not exceed 2 μg of phenol liberated by 1 ml of reconstituted milk.

6.2.3. Żid 10 ml ta' soluzzjoni c (4.3.2). Ħawwad u qiegħed it-tubu fil-banju ta' l-ilma fi 37 °C (5.2).

METHOD 8: DETERMINATION OF PHOSPHATASE ACTIVITY (ASCHAFFENBURG AND MÜLLEN PROCEDURE)

6.2.4. Inkuba għal 60 minuta fil-banju ta' l-ilma tħawwad perjodikament.

1. SCOPE AND FIELD OF APPLICATION

6.2.5. Trasferixxi t-tubi mmedjetament lejn il-banju ta' l-ilma jgħali (5.5) u saħħan għal żewġ minuti; kessaħ lejn it-temperatura tal-kamra f'ilma kiesaħ.

This method describes the determination of phosphatase activity in:

6.2.6. Żid 1 ml ta' soluzzjoni d (4.4), ħawwad u ffiltra minn karta tal-filtru niexfa; warrab l-ewwel filtrati sakemm likwidu ċar ikun akkwistat.

- dried high fat milk or high fat milk powder,

6.2.7. Qiegħed 5 ml minn kull filtrat f'tubi tat-testijiet, żid 5 ml ta'soluzzjoni b (4.2) u 0.1 ml ta' soluzzjoni c (4.5). Ħallat.

- dried whole milk or whole milk powder,

6.2.8. Ħalli li l-kulur jiżviluppa f'temperatura tal-kamra għal 30 minuta lil hinn minn dawl dirett tax-xemx.

- dried partly skimmed milk or partly skimmed-milk powder,

6.2.9. Kejjel id-densità ottika tas-soluzzjoni tal-kampjun, kontra l-vġut, fil-wavelength indikata fi 5.3.

- dried skimmed milk or skimmed-milk powder.

6.2.10. Irrepeti d-determinazzjoni jekk id-densità ottika tas-soluzzjoni tkun il-fuq minn dik tal-kampjun standard b'20 μg ta' fenol ippreparat skond 7.

2. DEFINITION

Jekk dan il-limitu jkun misbuq, dewweb volum addattat ta' ħalib rikonstitwit bi qbil ma 6.1.1 b'volum xieraq ta' dan il-ħalib u b'galbu għalli kif indikat fi 6.2.2 biex tiddiattiva l-fosfatażi preżenti.

The phosphatase activity of dried milks is a measure of the quantity of active alkaline phosphatase present in the product. It is expressed as the quantity of p-nitrophenol in micrograms liberated by 1 ml of the reconstituted sample, under the conditions described.

7. PREPARAZZJONI TAL-KURVA STANDARD

3. PRINCIPLE

7.1. Bil-pipetta qiegħed f'erba' kunjetti volumetrii ta 100 ml, 1, 3, 5 u 10 ml tas-soluzzjoni standard mdewwba skond 4.8 u wassal il-volum bl-ilma; dan it-tidwib fih rispettivament 2, 6, 10 u 20 μg ta' fenol għal kull ml.

The reconstituted sample is diluted with a buffer substrate at pH 10,2 and incubated at a temperature of 37 oC for two hours. Any alkaline phosphatase present in the sample will, under these circumstances, liberate p-nitrophenol from added disodium p-nitrophenyl phosphate. The p-nitrophenol liberated is determined by direct comparison with standard colour glasses in a simple comparator using reflected light.

7.2. Bil-pipetta qiegħed 1 ml ta' ilma jew 1 ml ta' kull waħda mis-soluzzjonijiet normali (7.1) fit-tubi tat-testijiet sabiex takkwista serje ta' kampjuni li jkun fihom 0 (valur vġut akkwistat bl-użu tal-1 ml ta' ilma) - 2 -6 - 10 u 20 μg ta' fenol.

4. REAGENTS

7.3. Bil-pipetta qiegħed suċessivament f'kull tubu tat-testijiet 1 ml tas-soluzzjoni ta' sulfat tar-ramm (ii) (4.7), 5 ml tas-soluzzjoni tal-kuxxinett tat-tidwib tal-kulur (4.6), 3 ml ta' ilma u 0.1 ml ta' soluzzjoni (4.5). Ħallat.

4.1. Sodium carbonate-bicarbonate buffer solution.

7.4. Ħalli t-tubi tat-testijiet għal 30 minuta f'temperatura tal-kamra lil hinn minn dawl dirett tax-xemx.

Dissolve 3,5 g of anhydrous sodium carbonate and 1,5 g of sodium bicarbonate in water and dilute to 1000 ml in a volumetric flask with water.

7.5. Kejjel l-assorbenza tas-soluzzjonijiet f'kull wieħed mit-tubi, mqabbla mall-valur il-vġut, fil-wavelength indikata fi 5.3.

4.2. Buffer substate.

7.6. Ipprepara l-kurva standard billi timmarka l-valuri ta' l-assorbenza kontra l-kwantitajiet ta' fenol f'ug kif indikat fi 7.2.

Dissolve 1,5 g of disodium p-nitrophenylphosphate in sodium carbonate-bicarbonate buffer (4.1) and dilute to 1000 ml in a volumetric flask with buffer (4.1).

8. ESPRESSJONI TAR-RIŻULTATI

This solution is stable if stored in a refrigerator (≤ 4 oC) for one month but a colour control test should be carried out on such stored solutions — see 6, precaution number 3.

8.1. Kalkolazzjoni

4.3. Clarification solutions.

8.1.1. Ikkonverti l-figuri kif determinat skond 6.2.9 ma μg ta' fenol, b'referenza għal kurva standard.

4.3.1. Zinc sulphate solution.

8.1.2. Ikkalkola l-attività tal-fosfatażi espressa bħala μg ta' fenol għal kul ml ta' ħalib rikonstitwit skond il-formula segwenti:

Dissolve 30,0 g of zinc sulphate (ZnSO4) in water and dilute to 100 ml in a volumetric flask with water.

Attività fosfatażi = 2.4 × p

4.3.2. Potassium hexacyanoferrate (II) solution.

Fejn p = il-kwantità ta' fenol f'uh bi qbil ma 8.1.1.

Dissolve 17,2 g of potassium hexacyanoferrate (II) trihydrate (K4Fe(CN)6.3H20) and dilute to 100 ml in a volumetric flask with water.

8.1.3. Jekk kien meħtieġ li jkun hemm tidwib kif indikat permezz ta' 6.2.10 immultiplika r-riżultat akkwistat fi 8.1.2 bil-fattur tat-tidwib.

5. APPARATUS

8.2. Repetabilità

5.1. Analytical balance.

Id-differenza bejn ir-riżultati taż-żewġ determinazzjonijiet imwettqa simultanjament jew f'sekwenza mgħaġla fuq l-istess kampjun, mill-istess analista, taħt l-istess kondizzjonijiet, m'għandhiex teċċedi 2 μg ta' fenol liberat bi 1 ml ta' ħalib rikonstitwit.

5.2. Waterbath, thermostatically controlled at 37 oC ± 1 oC.

METODU 8:

5.3. Comparator, with special disc containing standard colour glasses calibrated in μg p-nitrophenol per ml milk, and 2 x 25 mm cells.

DETERMINAZZJONI TA' ATTIVITA TA' FOSFATAŻI (PROĊEDURA ASCHAFFENBURG U MULLEN)

6. PROCEDURE

1. SKOP U QASAM TA' APPLIKAZZJONI

Precautions:

Dan il-metodu jiddeskrivi d-determinazzjoni ta' l-attività tal-fosfatażi fi:

1. After use, test tubes must be emptied, rinsed in water, washed in hot water containing an al kaline detergent, followed by thorough rinsing in clean hot tap water. Finally, they must be rinsed in water and dried before use.

- ħalib niexef b'xaħam għoli jew trab tal-ħalib b'xaħam għoli,

Pipettes must be thoroughly rinsed in clean cold tap water immediately after use, followed by rinsing in water and dried before use.

- ħalib komplut niexef jew trab tal-ħalib komplut,

2. The test tube stoppers must be thoroughly rinsed in hot tap water immediately after use, followed by boiling for two minutes in water.

- ħalib niexef parzjalment xkumat jew trab tal-ħalib parzjalment xkumat,

3. The buffer substrate solution (4.2) should remain stable for at least one month if stored in a refrigerator at 4 oC or less. Any instability is denoted by the formation of a yellow colour. Whilst the test is always read against a boiled product control containing the same buffer substrate solution, it is recommended that the solution should not be used if it gives a colour reading in excess of 10 μg when read in a 25 mm cell in the comparator using distilled water in the other 25 mm cell.

- ħalib niexef xkumat jew trab tal-ħalib xkumat.

4. Use a separate pipette for each sample and avoid contaminating the pipette with saliva.

2. DEFINIZZJONI

5. The test must not be exposed to direct sunlight at any time.

L-attività fosfatażi ta' ħalib niexef hija kejl tal-kwantità ta' attività ta' fosfatażi alkalina preżenti fil-prodott. Hija espressa bħala l-kwantità ta' p-nitrophenol, f'mikrogrammi liberati b'1 ml ta' kampjun rikonstitwit, skond il-kondizzjonijiet deskritti.

6.1. Preparation of sample

3. PRINĊIPJU

Dissolve 10 g of the powder in 90 ml of water. The temperature for dissolving the powder must not exceed 35 oC.

Il-kampjun rikonstitwit huwa mdewweb b'substrata tal-kuxxinett fi ph 10.2 u inkubat f'temperatura ta' 37 °C għal sagħtejn. Xi fosfatażi alkalina preżenti fil-kampjun għandha, skond dawn iċ-ċirkostanzi, tillibera p-nitrophenol minn disodium p-nitrophenyl phosphate miżjud. Il-p-nitrophenol illiberat huwa ddeterminat bi tqabbil dirett mal-ħġieġ tal-kulur standard fi tqabbil sempliċi billi tuża dawl rifless.

6.2. Determination

4. REAĠENTI

6.2.1. Pipette 15 ml of buffer substrate (4.2) into a clean, dry test tube, followed by 2 ml of the reconstituted sample (6.1) to be tested. Stopper the tube, mix by inversion and place in the 37 oC water bath (5.2).

4.1. Soluzzjoni tal-kuxxinet tal-karbonat-bikarbonat tas-sodju.

6.2.2. At the same time, place in the water bath a control tube containing 15 ml of buffer substrate and 2 ml of boiled reconstituted sample similar to that under test.

Ħoll 3.5 g ta' karbonat tas-sodju anhydrous u 1.5 g ta' bikarbonat tas-sodju fl-ilma u dewweb għal 1000 ml f'kunjett volumtriku bl-ilma.

6.2.3. After two hours remove both tubes from the water bath, add 0,5 ml of zinc sulphate precipitant (4.3.1), replace the stopper, shake vigorously and allow to stand for three minutes. Add 0,5 ml of potassium hexacyanoferrate (II) precipitant (4.3.2), mix thoroughly and filter through the fluted filter paper (5.4) and collect the clear filtrate in the clean test tube.

4.2. Kuxxinett sub-strata.

6.2.4. Transfer the filtrate to a 25 mm cell and compare against the filtrate of the boiled sample control in the comparator using the special disc (5.3).

Ħoll 1.5 g ta' disodju p-nitrophenyl phosphate f'kuxxinett ta' sodju tal-karbonat-bikarbonat (4.1) u dewweb lejn 1000 ml f'kunjett volumetriku b'kuxxinett (4.1).

7. EXPRESSION OF RESULTS

Din is-soluzzjoni hija stabbli jekk maħżuna f'refriġerejter ( 4 °C) għal xhar wieħed imma test ta' konroll tal-kulur għandu jkun imwettaq fuq soluzzjonijiet bħal dawn li jkunu maħżuna - ara 6, prekwazjoni numru 3.

7.1. Calculation

4.3. Soluzzjonijiet ta' kjarifika.

The direct reading obtained under 6.2.4 is recorded as μg p-nitrophenol per ml sample or per ml of reconstituted sample.

4.3.1. Soluzzjoni tas-sulfat taż-żingu.

7.2. Repeatability

Ħoll 30.0 g ta' sulfat taż-żingu (ZnSO4) fl-ilma u dewweb għal 100 ml f'kunjett volumetriku bl-ilma.

The difference between the results of two determinations carried out simultaneously or in rapid succession on the same sample, by the same analyst, under the same conditions, shall not exceed 2 μg of p-nitrophenol liberated by 1 ml of reconstituted milk.

4.3.2. Soluzzjoni ta' hexacyanoferrate tal-potassju (ii).

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Dewweb 17.2 g ta' hexacyanoferrate tal-potassju (ii) trihydrate (K4Fe(CN)6.3H2O) u dewweb għal 100 ml f'kunjett volumetriku bl-ilma.

5. Apparat

5.1. Miżien analitiku.

5.2. Banju ta' l-ilma, ikkontrollat termostatikament fi 37 °C aktar jew anqas 1 °C.

5.3. Komparatur, b'diska speċjali li jkun fiha ħġieġ standard tal-kulur ikkalibrat f'ug p-nitrophenol għal kull ml ħalib, u 2 ċelloli ta' 25 mm.

6. PROĊEDURA

Prekawzjonijiet:

1. Wara l-użu, it-tubi tat-testijiet għandhom ikunu mbattla, mlaħalħa fl-ilma, maħsula f'ilma sħun li jkun fih deterġent alkalin, segwit bi tlaħlieħ intensiv f'ilma sħun nadifmil-vit. Finalment, għandhom ikunu mlaħalħa f'ilma u mnixxfa qabel l-użu.

Il-pipetti għandhom ikunu kompletament imlaħalħa f'ilma frisk nadif tal-vit immedjetament wara l-użu, segwit bi tlaħliħ fl-ilma u mnixxfa qabel l-użu.

2. It-tappini tat-tubi tat-testijiet għandhom ikunu kompletament imlaħalħa fl-ilma sħun tal-vit immedjetament wara l-użu segwiti b'tgħolija għal żewġ minuti fl-ilma.

3. Is-soluzzjoni ta' substrata tal-kuxxinett (4.2) għandha tibqa stabbli mill-anqas xhar wieħed jew maħżuna f'refriġerejterfi 4 °C jew anqas. Xi instabilità hija murijha bil-formazzjoni ta' lewn safrani. Waqt li t-test għandu dejjem jinqara kontra l-prodott mgħolli tal-kontroll li jkun fih l-istess soluzzjoni substrata tal-kuxxinett, huwa rrakkomandat li s-soluzzjoni m'għandiex tkun użata jekk tgħati qari ta' kulur b'eċċess ta' 10 μg meta l-qari jsir f'ċellola ta' 25 mm fil-kumparatur li juża ilma ddistillat fiċ-ċellola l-oħra ta'25 mm.

4. Uża pipetta separata għal kull kampjun u evita l-kontaminazjoni tal-pipetta bil-bżieq.

5. It-test m'għandux ikun espost għal dawl dirett tax-xemx fi kwalunkwe ħin.

6.1. Preparazzjoni tal-kampjun

Ħoll 10 g tat-trab fi 90 ml ta' ilma. It-temperatura għat-tħollija tat-trab m'għandiex teċċedi 35 °C.

6.2. Determinazzjoni

6.2.1. Bil-pipetta għaddi 15 ml tas-substrata tal-kuxxinett (4.2) f'tubu tat-testijiet li jkun nadif u xott, segwit b'2 ml tal-kampjun rikonstitwit (6.1) li għandu jkun ittestjat. Poġġi t-tappin fuq it-tubi, ħawwad bit-taqlib u qiegħed fil-banju ta' l-ilma fi 37 °C (5.2).

6.2.2. Fl-istess waqt, qiegħed fil-banju ta' l-ilma tubu ta' kontroll li jkun fih 15 ml ta' kuxxinett ta' substrata u 2 ml ta' kampjun mgħolli rikonstitwit simili għal dak li jkun qiegħed jiġi ttestjat.

6.2.3. Wara sagħtejn neħħi iż-żewġ tubi mill-banju ta' l-ilma, żid 0.5 ml ta' preċipitant tas-sulfat taż-żingu (4.3.1), erġa' poġġi t-tappin, ħawwad bil-qawwi u ħalli joqgħod għal tliet minuti. Żid 0.5 ml ta' preċipitant ta' hexacyanoferrate tal-potassju (ii) (4.3.2), ħawwad kompletament u iffiltra minn karta tal-filtru f'għamla ta lembut (5.4) u iġbor il-filtrat ċar fit-tubu tat-testijiet nadif.

6.2.4. Trasferixxi l-filtrat lejn ċellola ta' 25 mm u qabbel kontra l-filtrat tal-kampjun mgħolli kkontrollat fil-kumparatur bl-użi tad-diska speċjali (5.3).

7. ESPRESSJONI TAR-RIŻULTATI

7.1. Kalkolazzjoni

Il-qari dirett akkwistat permezz ta' 6.2.4 huwa rreġistrat bħala μg p-nitrophenol għal kull ml tal-kampjun jew għal kull ml tal-kampjun rikonstitwit.

7.2. Repetabilità

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