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Document 32008R0273

Commission Regulation (EC) No 273/2008 of 5 March 2008 laying down detailed rules for the application of Council Regulation (EC) No 1255/1999 as regards methods for the analysis and quality evaluation of milk and milk products

OJ L 88, 29.3.2008, p. 1–115 (BG, ES, CS, DA, DE, ET, EL, EN, FR, IT, LV, LT, HU, MT, NL, PL, PT, RO, SK, SL, FI, SV)

This document has been published in a special edition(s) (HR)

Legal status of the document No longer in force, Date of end of validity: 06/02/2018; Repealed by 32018R0150

ELI: http://data.europa.eu/eli/reg/2008/273/oj

29.3.2008   

EN

Official Journal of the European Union

L 88/1


COMMISSION REGULATION (EC) No 273/2008

of 5 March 2008

laying down detailed rules for the application of Council Regulation (EC) No 1255/1999 as regards methods for the analysis and quality evaluation of milk and milk products

THE COMMISSION OF THE EUROPEAN COMMUNITIES,

Having regard to the Treaty establishing the European Community,

Having regard to Council Regulation (EC) No 1255/1999 of 17 May 1999 on the common organisation of the market in milk and milk products (1), and in particular Articles 10 and 15 and Articles 26(3), 29(1) and 31(4) thereof,

Whereas:

(1)

Commission Regulation (EC) No 213/2001 (2) lays down detailed rules for the application of Council Regulation (EC) No 1255/1999 as regards methods for the analysis and quality evaluation of milk and milk products. In the light of technical developments in the field of analytical methodology further substantial changes need to be made. In the interest of clarity and efficiency and given the number and technical nature of the amendments, Regulation (EC) No 213/2001 should be repealed and replaced by a new regulation.

(2)

The composition and quality requirements for milk and milk products laid down under the arrangements provided for in Regulation (EC) No 1255/1999 must be verified to ensure that they are strictly complied with.

(3)

The reference methods for such verifications are often methods published by international organisations such as the European Committee for Standardization (CEN), the International Dairy Federation (IDF), the International Organisation for Standardisation (ISO) and the Scientific Association dedicated to the analytical Excellence (AOAC International), which are regularly updated by those organisations. In some cases a Community reference method is laid down, while in other cases no reference method is specified in the Community rules. In order to ensure that reference methods are uniformly applied, a list of reference methods should be drawn up and provision should be made for the Commission to adapt the list where necessary.

(4)

The use of routine methods should not be ruled out. Minimal conditions for using them should therefore be specified.

(5)

Common procedures should also be established to ensure uniform practice in evaluating the results of analyses, in sensory evaluation of the products concerned and in re-examining results which have been disputed.

(6)

For some analyses, there are currently no internationally accepted reference methods which have been validated and thus no information is available on the between-laboratory-variation of analytical results. Community methods should therefore be laid down, which have been validated according to internationally established rules and should be applied as reference methods.

(7)

Commission Regulation (EC) No 1898/2005 (3) lays down detailed rules for implementing Council Regulation (EC) No 1255/1999 as regards measures for the disposal of cream, butter and concentrated butter on the Community market and provides for the tracing of cream, butter and concentrated butter in certain circumstances in order to ensure the correct end use of these products. Tracing is important for the proper functioning of the scheme. In order to ensure that operators participating in it receive equal treatment, common methods should be established for determining some of these tracers.

(8)

Under Article 9 of Regulation (EC) No 1255/1999, private storage aid may be granted for cheeses made from ewes’ milk. A special refund for the same products can be granted under Article 31 of that Regulation. Cheeses made from ewes’ milk, goats’ milk, buffalos’ milk and mixtures of ewes’, goats’ and buffalos’ milk may be imported into the Community under preferential arrangements from certain third countries. In view of the above, appropriate checks are needed to ensure that no cow’s milk has been incorporated in the products concerned. A Community reference method should therefore be established for detecting cow’s milk, without prejudice to the use of routine methods, provided they comply with certain criteria.

(9)

Under Commission Regulation (EEC) No 2921/90 of 10 October 1990 on aid for the production of casein and caseinates from skimmed milk (4), the absence of coliforms must be detected. The internationally accepted reference methods for detecting coliforms in milk and milk products is ISO 4831. A Community reference method for detecting coliforms has been established based on the abovementioned standard.

(10)

Council Regulation (EEC) No 2658/87 of 23 July 1987 on the tariff and statistical nomenclature and on the Common Customs Tariff (5) provides for different rates of customs duty for compound feedingstuffs falling within tariff heading No 2309, depending on their milk-product content. To ensure that the rules in question are uniformly applied, a generally recognised method for analysing lactose content should be laid down for compulsory use in all Member States.

(11)

Under Regulation (EC) No 1255/1999, butter and skimmed-milk powder intended for intervention or, in the case of skimmed-milk powder, for use as animal feed, must meet certain quality requirements. Reference methods should be laid down to verify that those requirements are met.

(12)

Some methods are introduced for the first time in this Regulation. A sufficient period from the time of entry into force of this Regulation should be provided in order to allow laboratories to correctly introduce and use these new methods. Whenever a reference method referred to in Annex I is revised and published by the Standards Developing Organisation, the laboratories should be allowed six months to update their analytical procedures to conform to the new standard.

(13)

The measures provided for in this Regulation are in accordance with the opinion of the Management Committee for Milk and Milk products,

HAS ADOPTED THIS REGULATION:

CHAPTER I

GENERAL PROVISIONS

Article 1

Subject matter and scope

1.   This Regulation lays down certain reference methods for the chemical, physical and microbiological analysis and sensory evaluation of milk and milk products to be used under the arrangements provided for in the common organisation of the market in milk and milk products established by Regulation (EC) No 1255/1999 and the rules for applying those methods.

2.   The list of the reference methods applicable to analyses as referred to in paragraph 1 is laid down in Annex I to this Regulation.

3.   The Commission shall update the list in accordance with the procedure laid down in Article 42 of Regulation (EC) No 1255/1999.

Article 2

Routine methods

Routine methods may be used for analyses required by the Community rules provided that they are properly calibrated and regularly checked against the reference method. Results shall be compared taking into account the constant bias, the repeatability and the reproducibility.

In cases of dispute, the result obtained by the reference method shall be decisive.

Member States shall inform the Commission on the use of routine methods in the analysis referred to in Article 1.

CHAPTER II

METHODS OF ANALYSIS

Article 3

Evaluation of compliance of a consignment with a legal limit

Except for the analysis of tracers, Annex II to this Regulation shall apply in order to define compliance with legal compositional requirements.

Article 4

Sensory evaluation

1.   For milk and milk products other than butter for public storage, the reference method to be used by the Member States for sensory evaluation shall be either IDF standard 99C:1997 or other comparable methods which they shall notify to the Commission.

The procedures described in Annex III shall be applied to check the performance of assessors and the reliability of results in sensory analyses.

2.   For butter for public storage, the procedures described in Annex III shall be applied to check the performance of assessors and the reliability of results in sensory analyses.

The procedure laid down in Annex IV shall be applied as a reference method for sensory evaluation.

Article 5

Tracers

1.   The method of analysis laid down in Annex V shall be used as the reference method for determining the content of enanthic acid triglyceride in butter, butter-oil and cream.

2.   The method of analysis laid down in Annex VI shall be used as the reference method for determining vanillin in concentrated butter, butter and cream.

3.   The method of analysis laid down in Annex VII shall be used as the reference method for determining the ethyl ester of beta-apo-8' carotenic acid content of concentrated butter and butter.

4.   The analysis method laid down in Annex VIII shall be used as the reference method for determining the β-sitosterol or stigmasterol content of butter and concentrated butter.

5.   Concentrated butter, butter and cream are considered to be traced in conformity with the relevant Community rules if the results obtained are in accordance with the specifications of points 10 and 11 of Annex V and point 8 of Annexes VI, VII and VIII.

Article 6

Detection of cows’ milk casein

1.   The reference method of analysis laid down in Annex IX shall be used to ensure that cheese made exclusively from ewes’ milk, goats’ milk or buffalos’ milk or from a mixture of ewes’, goats’ and buffalos’ milk does not contain cows’ milk casein.

Cows’ milk casein is considered to be present if the cows’ milk casein content of the analysed sample is equal to or higher than the content of the reference sample containing 1 % cows’ milk as laid down in Annex IX.

2.   Routine methods for detecting cows’ milk casein in cheeses referred to in paragraph 1 may be used provided that:

(a)

the detection limit is maximum 0,5 %; and

(b)

there are no false-positive results; and

(c)

cows’ milk casein is detectable with the required sensitivity even after long ripening periods, as may occur in usual commercial conditions.

If any of the above mentioned requirements is not met, the reference methods laid down in Annex IX shall be used.

Article 7

Detection of coliforms

Coliforms in butter, skimmed-milk powder, casein and caseinates shall be detected in accordance with the reference method laid down in Annex X.

Article 8

Determination of the lactose content

The lactose content of products falling within CN code 2309 shall be determined in accordance with the reference method laid down in Annex XI.

Article 9

Detection of rennet whey

1.   Rennet whey in skimmed-milk powder intended for public storage shall be detected in accordance with the reference method laid down in Annex XII.

2.   Rennet whey in skimmed-milk powder and mixtures intended for use as animal feed shall be detected in accordance with the reference method laid down in Annex XII. In case of detection of rennet whey, Annex XIII should be implemented.

Article 10

Detection of buttermilk

Buttermilk in skimmed-milk powder shall be detected in accordance with the reference method laid down in Annex XIV.

Article 11

Detection of antimicrobiotic residues

Antimicrobial residues in skimmed-milk powder shall be detected in accordance with the reference method laid down in Annex XV.

Article 12

Determination of skimmed-milk powder content

Skimmed-milk powder content in compound feedingstuffs shall be determined in accordance with the reference method laid down in Annex XVI.

Article 13

Detection of starch

Starch in skimmed-milk powder, denatured milk powder and compound feedingstuffs shall be detected in accordance with the reference method laid down in Annex XVII.

Article 14

Determination of moisture content in dried cream

Moisture content in dried cream shall be determined in accordance with the reference method laid down in Annex XVIII.

Article 15

Determination of moisture content of acid buttermilk powder

Moisture content in acid buttermilk powder intended for use in feedingstuffs shall be determined in accordance with the reference method laid down in Annex XIX.

Article 16

Determination of milk fat purity

Milk fat purity shall be determined in accordance with the reference method laid down in Annex XX.

CHAPTER III

GENERAL AND FINAL PROVISIONS

Article 17

Quality assurance

Analyses shall be performed in laboratories having an analytical quality assurance system including internal quality control procedures. Not accredited laboratories shall participate in proficiency testing schemes at least once per year and their results shall not deviate by more than 2σR (reproducibility standard deviation of the reference method) from the consensus value. A detailed description of the systems used shall be available for consultation in the laboratory.

Laboratories that are accredited in accordance with the standards referred to in Article 12 of Regulation (EC) No 882/2004 of the European Parliament and of the Council of 29 April 2004 on official controls performed to ensure the verification of compliance with feed and food law, animal health and animal welfare rules (6) shall be exempted from the obligation to participate in proficiency testing.

Article 18

Sampling and disputes over the results of analysis

1.   Sampling shall be carried out in accordance with the relevant regulation for the product under consideration. If no sampling provisions are presented, then the provision given in ISO 707 | IDF 50, Milk and milk products — Guidance of sampling, shall be used.

2.   Laboratory reports of the results of the analysis must contain sufficient information for an evaluation of the results to be made in accordance with Annex II and Annex XXI.

3.   Duplicate samples must be taken for analyses required under Community rules.

4.   The procedure described in Annex XXI shall be used in cases where the results of an analysis are not accepted by the operator.

5.   If the manufacturer can prove, within five working days of sampling, that the sampling procedure was not carried out correctly, sampling must be repeated where possible. If sampling cannot be repeated, the consignment must be accepted.

Article 19

Transition period

Evaluation of compliance according to Annex II to this Regulation shall be performed within 12 months after its entry into force. Member States will immediately report to the Commission where necessary if any major problem is encountered during this period with the statistical control procedure.

Article 20

Repeals

Regulation (EC) No 213/2001 is repealed.

References to the repealed Regulation shall be construed as references to this Regulation and shall be read in accordance with the correlation table in Annex XXII.

Article 21

Entry into force

This Regulation shall enter into force on the third day following that of its publication in the Official Journal of the European Union.

It shall apply from 31 March 2008.

This Regulation shall be binding in its entirety and directly applicable in all Member States.

Done at Brussels, 5 March 2008.

For the Commission

Mariann FISCHER BOEL

Member of the Commission


(1)   OJ L 160, 26.6.1999, p. 48. Regulation as last amended by Regulation (EC) No 1152/2007 (OJ L 258, 4.10.2007, p. 3). Regulation (EC) No 1255/1999 will be replaced by Regulation (EC) No 1234/2007 (OJ L 299, 16.11.2007, p. 1) as from 1 July 2008.

(2)   OJ L 37, 7.2.2001, p. 1.

(3)   OJ L 308, 25.11.2005, p. 1. Regulation as last amended by Regulation (EC) No 1546/2007 (OJ L 337, 21.12.2007, p. 68).

(4)   OJ L 279, 11.10.1990, p. 22. Regulation as last amended by Regulation (EC) No 1487/2006 (OJ L 278, 10.10.2006, p. 8).

(5)   OJ L 256, 7.9.1987, p. 1. Regulation as last amended by Commission Regulation (EC) No 1352/2007 (OJ L 303, 21.11.2007, p. 3).

(6)   OJ L 165, 30.4.2004, p. 1.


ANNEX I

(Article 1)

LIST OF REFERENCE METHODS

Index Min. = minimum, Max. = maximum, Annex = Annex to quoted Regulation, SNF = solids non fat, PV = peroxide value, A = appearance, F = flavour, C = consistency, TBC = total bacterial count, Therm = thermophilic bacterial count, MS = Member State, IDF = International Dairy Federation, ISO = International Standards Organisation, IUPAC = International Union of Pure and Applied Chemistry, ADPI = American Dairy Products Institute, SCM = sweetened condensed milk, EMC = evaporated milk or cream.

PART A

Commission Regulation

Product

Parameter

Limit (1)

Reference method

Remark

Regulation (EC) No 2771/1999 — Public storage

Unsalted butter

Fat

Min. 82 % m/m

ISO 17189:2003|IDF 194:2003

 

 

 

Water

Up to 16 % m/m

ISO 3727-1:2001|IDF 80-1:2001

 

 

 

SNF

Up to 2 % m/m

ISO 3727-2:2001|IDF 80-2:2001

 

 

 

Fat acidity

1,2 mmole/100 g of fat

ISO 1740:2004|IDF 6:2004

 

 

 

PV (max.)

0,3 meq. oxygen/1 000  g fat

ISO 3976:2006|IDF 74:2006

Note 1

 

 

Coliforms

Not detectable in 1 g

Annex X

Note 3

 

 

Non-milk fat

Not detectable by triglyceride analysis

Annex XX

 

 

 

Sterol tracers

Not detectable, β-sitosterol ≤ 40 mg/kg

Annex VIII

 

 

 

Other tracers

 

 

 

 

 

vanillin

Not detectable

Annex VI

 

 

 

ethyl ester of carotenic acid

≤ 6 mg/kg

Annex VII

 

 

 

triglycerides of enanthic acid

Not detectable

Annex V

 

 

 

Sensory characteristics

At least 4 out of 5 points for A, F and C

Annex IV

 

 

 

Water dispersion

At least 4 points

ISO 7586:1985 — IDF 112A:1989

 

Regulation (EC) No 2771/1999 — Private storage

Unsalted butter

Fat

Min. 82 % m/m

ISO 17189:2003|IDF 194:2003

 

 

 

Water

Up to 16 % m/m

ISO 3727-1:2001|IDF 80-1:2001

 

 

 

SNF

Up to 2 % m/m

ISO 3727-2:2001|IDF 80-2:2001

 

Regulation (EC) No 2771/1999 — Private storage

Salted butter

Fat

Min. 80 % m/m

ISO 17189:2003|IDF 194:2003

 

 

 

Water

Up to 16 % m/m

ISO 3727-1:2001|IDF 80-1:2001

 

 

 

SNF (excluding salt)

Up to 2 % m/m

ISO 3727-2:2001|IDF 80-2:2001

 

 

 

Salt

Up to 2 % m/m

ISO 15648:2004|IDF 179:2004

 

Regulation (EC) No 1898/2005 chapter II

Unsalted butter

Fat

Min. 82 % m/m

ISO 17189:2003|IDF 194:2003

 

 

 

Non-milk fat

 

Annex XX

 

 

 

Water

Up to 16 % m/m

ISO 3727-1 2001|IDF 80-1:2001

 

 

 

SNF

Up to 2 % m/m

ISO 3727-2:2001|IDF 80-2:2001

 

 

 

Tracers:

 

 

 

 

 

sterols

See Annex VIII

Annex VIII

 

 

 

vanillin

See Annex VI

Annex VI

 

 

 

ethyl ester of carotenic acid

See Annex VII

Annex VII

 

 

 

triglycerides of enanthic acid

See Annex V

Annex V

 

Regulation (EC) No 1898/2005 chapter II

Salted butter

Fat

Min. 80 % m/m

ISO 17189:2003|IDF 194:2003

 

 

 

Non-milk fat

 

Annex XX

 

 

 

Water

Up to 16 % m/m

ISO 3727-1:2001|IDF 80-1:2001

 

 

 

SNF (excluding salt)

Up to 2 % m/m

ISO 3727-2:2001|IDF 80-2:2001

 

 

 

Salt

Up to 2 % m/m

ISO 15648:2004|IDF 179:2004

 

 

 

Tracers:

 

 

 

 

 

sterols

See Annex VIII

Annex VIII

 

 

 

vanillin

See Annex VI

Annex VI

 

 

 

ethyl ester of carotenic acid

See Annex VII

Annex VII

 

 

 

triglycerides of enanthic acid

See Annex V

Annex V

 

Regulation (EC) No 1898/2005 chapter II

Concentrated butter

Fat

Min. 99,8 % m/m

IDF 24:1964

 

 

 

Water and SNF

Up to 0,2 % m/m

ISO 5536:2002|IDF 23:2002 (moisture)

IDF 24:1964 (SNF)

 

 

 

Fat acidity

1,2 mmole/100 g of fat

ISO 1740:2004|IDF 6:2004

 

 

 

PV (max.)

0,5 meq. oxygen/1 000  g fat

ISO 3976:2006|IDF 74:2006

Note 1

 

 

Non-milk fat

Absence

Annex XX

 

Flavour

Clean

Smell

Absence of foreign odours

Other

Absence of neutralising agents, anti-oxidants and preservatives

 

 

Tracers:

 

 

 

sterols

See Annex VIII

Annex VIII

vanillin

See Annex VI

Annex VI

ethyl ester of carotenic acid

See Annex VII

Annex VII

triglycerides of enanthic acid

See Annex V

Annex V

Regulation (EC) No 1898/2005 chapter II

Cream

Fat

Minimum 35 % m/m

ISO 2450:1999|IDF 16 C:1987

 

 

 

Non-milk fat

 

Annex XX

 

 

 

Tracers:

 

 

 

sterols

See Annex VIII

 

Note 2

 

 

vanillin

See Annex VI

Annex VI

 

 

 

ethyl ester of carotenic acid

See Annex VII

 

Note 2

 

 

triglycerides of enanthic acid

See Annex V

Annex V

 

Regulation (EC) No 1898/2005 chapter III

Concentrated butter

Fat

Min. 96 % m/m

 

Note 2

 

 

Non-milk fat

 

Annex XX

 

 

 

SNF

Up to 2 % m/m

 

Note 2

 

 

Tracers:

 

 

 

stigmasterol (95 % m/m)

15 g/100 kg of concentrated butter

Annex VIII

 

 

stigmasterol (85 % m/m)

17 g/100 kg of concentrated butter

Annex VIII

 

 

 

triglycerides of enanthic acid

10,34 kg/t of concentrated butter

Annex V

 

 

 

ethyl ester of butyric acid and stigmasterol

 

ethyl ester of butyric acid

stigmasterol: Annex VIII

Note 2

 

 

ethyl ester of butyric acid and triglycerides of enanthic acid

 

ethyl ester of butyric acid

triglycerides of enanthic acid: Annex V

Note 2

 

 

lecithin (E 322)

Up to 0,5 % m/m

 

Note 2

 

 

NaC1

Up to 0,75 % m/m

ISO 15648:2004|IDF 179:2004

 

 

 

Fat acidity

1,2 mmole/100 g of fat

ISO 1740:2004|IDF 6:2004

 

 

 

PV (max.)

Up to 0,5 meq. oxygen/1 000  g fat

ISO 3976:2006|IDF 74:2006

Note 1

 

 

Flavour

Clean

 

 

 

 

Smell

Absence of foreign odours

 

 

 

 

Other

Absence of neutralising agents, anti-oxidants and preservatives

 

 

Regulation (EC) No 1898/2005 chapter IV

Unsalted butter

Fat

Min. 82 % m/m

ISO 17189:2003|IDF 194:2003

 

 

 

Water

Up to 16 % m/m

ISO 3727-1:2001|IDF 80-1:2001

 

 

 

SNF

Up to 2 % m/m

ISO 3727-2:2001|IDF 80-2:2001

 

Regulation (EC) No 1898/2005 chapter IV

Salted butter

Fat

Min. 80 % m/m

ISO 17189:2003|IDF 194:2003

 

 

 

Water

Up to 16 % m/m

ISO 3727-1:2001|IDF 80-1:2001

 

 

 

SNF (excluding salt)

Up to 2 % m/m

ISO 3727-2:2001|IDF 80-2:2001

 

 

 

Salt

Up to 2 % m/m

ISO 15648:2004|IDF 179:2004

 

Article 9 and Title II of Regulation (EC) No 1255/1999

Cheese made from ewes’ and/or goats’ milk

Cows’ milk

< 1 % m/m

Annex IX

 

Regulation (EEC) No 2921/90

Annex I — Acid casein

Water

Up to 12,00 % m/m

ISO 5550:2006|IDF 78:2006

 

 

 

Fat

Up to 1,75 % m/m

ISO 5543:2004|IDF127:2004

 

 

 

Free acidity

Up to 0,30 ml of 0,1 N NaOH solution/g

ISO 5547:1978|IDF 91:1979

 

Regulation (EEC) No 2921/90

Annex I — Rennet- casein

Water

Up to 12,00 % m/m

ISO 5550:2006|IDF 78:2006

 

 

 

Fat

Up to 1,00 % m/m

ISO 5543:2004|IDF 127:2004

 

 

 

Ash

Min. 7,50 % m/m

ISO 5545:1978|IDF 90:1979

 

Regulation (EEC) No 2921/90

Annex I — Caseinates

Water

Up to 6,00 % m/m

ISO 5550:2006|IDF 78:2006

 

 

 

Milk protein

Min. 88,00 % m/m

ISO 5549:1978|IDF 92:1979

 

 

 

Fat and ash

Up to 6,00 % m/m

ISO 5543:2004|IDF 127:2004

 

 

 

Fixed ash

 

ISO 5544:1978|IDF 89:1979

 

 

 

Ash

 

ISO 5545:1978|IDF 90:1979

 

Regulation (EEC) No 2921/90

Annex II — Acid casein

Water

Up to 10,00 % m/m

ISO 5550:2006|IDF 78:2006

 

 

 

Fat

Up to 1,50 % m/m

ISO 5543:2004|IDF 127:2004

 

 

 

Free acidity

Up to 0,20 ml of 0,1 N NaOH solution/g

ISO 5547:1978|IDF 91:1979

 

 

 

TBC (max.)

30 000 / g

ISO 4833:2003

Note 3

 

 

Coliforms

Absence in 0,1 g

Annex X

Note 3

 

 

Therm. (max.)

5 000 / g

ISO 4833:2003

Notes 3 and 4

Regulation (EEC) No 2921/90

Annex II — Rennet-casein

Water

Up to 8,00 % m/m

ISO 5550:2006|IDF 78:2006

 

 

 

Fat

Up to 1,00 % m/m

ISO 5543:2004|IDF 127:2004

 

 

 

Ash

Min. 7,50 % m/m

ISO 5545:1978|IDF 90:1979

 

 

 

TBC (max.)

30 000 / g

ISO 4833:2003

Note 3

 

 

Coliforms

Absence in 0,1 g

Annex X

Note 3

 

 

Therm. (max.)

5 000 / g

ISO 4833:2003

Notes 3 and 4

Regulation (EEC) No 2921/90

Annex II — Caseinates

Water

Up to 6,00 % m/m

ISO 5550:2006|IDF 78:2006

 

 

 

Milk protein

Min. 88,00 % m/m

ISO 5549:1978|IDF 92:1979

 

 

 

Fat and ash

Up to 6,00 % m/m

ISO 5543:2004|IDF 127:2004

ISO 5544:1978|IDF 89:1979 or

ISO 5545:1978|IDF 90:1979

 

 

 

TBC (max.)

30 000 / g

ISO 4833:2003

Note 3

 

 

Coliforms

Absence in 0,1 g

Annex X

Note 3

 

 

Therm. (max.)

5 000 / g

ISO 4833:2003

Notes 3 and 4

Regulation (EEC) No 2921/90

Annex III — Caseinates

Water

Up to 6,00 % m/m

ISO 5550:2006|IDF 78:2006

 

 

 

Milk protein

Min. 85,00 % m/m

ISO 5549:1978|IDF 92:1979

 

 

 

Fat

Up to 1,50 % m/m

ISO 5543:2004|IDF 127:2004

 

 

 

Lactose

Up to 1,00 % m/m

ISO 5548:2004|IDF 106:2004

 

 

 

Ash

Up to 6,50 % m/m

ISO 5544:1978|IDF 89:1979 or ISO 5545:1978|IDF 90:1979

 

 

 

TBC (max.)

30 000 / g

ISO 4833:2003

Note 3

 

 

Coliforms

Absence in 0,1 g

Annex X

Note 3

 

 

Therm. (max.)

5 000 / g

ISO 4833:2003

Notes 3 and 4

Regulation (EC) No 2799/1999

Compound feedingstuffs and skimmed-milk powder (SMP) (for use in feedingstuffs)

Water (acid buttermilk powder)

Up to 5 % m/m

Annex XIX

 

 

 

Protein

31,4 % m/m (min.) of the non-fat dry matter

ISO 8968-1|2|3:2001|IDF 20-1|2|3:2001

 

 

 

Water (SMP)

Up to 5 % m/m

ISO 5537:2004|IDF 26:2004

 

 

 

Fats (SMP)

Up to 11 % m/m

ISO 1736:2000|IDF 9C:1987

 

 

 

Rennet whey (SMP)

Absence

Annex XIII

Note 6

 

 

Starch (SMP)

Absence

Annex XVII

 

 

 

Water (mixtures)

Up to 5 % m/m of the non-fat matter

ISO 5537:2004|IDF 26:2004

 

 

 

Fat (mixtures)

 

Commission Directive 84/4/EEC (OJ L 15, 18.1.1984, p. 29)

 

 

 

Rennet whey (mixtures)

Absence

Annex XIII

 

 

 

SMP content (of end product)

Min. 50 % m/m

Annex XVI

 

 

 

Fat (in end product)

Min. 2,5 % m/m or 5 % m/m

Commission Directive 84/4/EEC (OJ L 15, 18.1.1984, p. 29)

Note 7

 

 

Starch (in end product)

Min. 2 % m/m

Annex XVII

Note 8

 

 

Copper (in end product)

25 ppm

Commission Directive 78/633/EEC (OJ L 206, 26.7.1987, p. 43)

 

Regulation (EC) No 214/2001

SMP (spray)

Fat

Up to 1,0 % m/m

ISO 1736:2000|IDF 9C:1987

 

 

 

Protein

31,4 % (2) m/m (min.) of the non-fat dry matter

ISO 8968-1/2:2001|IDF 20-1/2:2001

 

 

 

Water

Up to 3,5 % m/m

ISO 5537:2004|IDF 26:2004

 

 

 

Acidity

Up to 19,5 ml, 0,1 N NaOH, 10 g solids non-fat

ISO 6091:1980|IDF 86:1981

 

 

 

Lactates

Up to 150 mg/100 g solids non-fat

ISO 8069:2005|IDF 69:2005

 

 

 

Phosphatase

Negative

ISO 11816-1:2006|IDF 155-1:2006

 

 

 

Insolubility index

Up to 0,5 ml at 24 °C

ISO 8156:2005|IDF 129:2005

 

 

 

Scorched particles

Disc A or B (15,0 mg)

ADPI (1990)

 

 

 

TBC

40 000 / g

ISO 4833:2003

Note 3

 

 

Coliforms

Negative/0,1 g

Annex X

Note 3

 

 

Buttermilk

Negative

Annex XIV

 

 

 

Rennet whey

Negative

Annex XII

 

 

 

Acid whey

Negative

 

Note 2

 

 

Anti-microbial agents

 

Annex XV

 


PART B

The reference methods listed in Part B may be used for analysing products covered by any of the Regulations listed in column 1.

Commission Regulation

Product

CN code

Parameter

Limit

Reference method

Remark

Regulation (EEC) No 2658/87

Regulation (EC) No 2535/2001

Regulation (EC) No 1282/2006

Milk and cream, not concentrated nor containing added sugar or other sweetening matter

0401

Fat (≤ 6 % m/m)

The limits are those specified in the description of the CN code for the specific product, further specified, where applicable, in Commission Regulation (EEC) No 3846/87 (OJ L 366, 24.12.1987, p. 1), Part 9 of the export nomenclature or Regulation (EC) No 2535/2001 (OJ L 341, 22.12.2001, p. 29)

ISO 1211:2001|IDF 1D:1996

 

 

 

 

Fat (> 6 % m/m)

 

ISO 2450:1999|IDF 16C:1987

 

 

Milk and cream, concentrated or containing added sugar or other sweetening matter

0402

Fat (liquid form)

 

ISO 1737:1999|IDF 13C:1987

 

 

 

 

Fat (solid form)

 

ISO 1736:2000|IDF 9C:1987

 

 

 

 

Protein

 

ISO 8968-1|2|3:2001|IDF 20-1|2|3:2001

 

 

 

 

Sucrose (normal content)

 

ISO 2911:2004|IDF 35:2004

 

 

 

 

Sucrose (low content)

 

 

Note 2

 

 

 

Solids (SCM)

 

ISO 6734:1989|IDF 15B:1991

 

 

 

 

Solids (EMC)

 

ISO 6731:1989|IDF 21B:1987

 

 

 

 

Water (milk powder)

 

ISO 5537:2004|IDF 26:2004

 

 

 

 

Water (cream powder)

 

Annex XVIII

 

 

Buttermilk, fermented or acidified milk and cream, concentrated or not concentrated, containing added sugar or other sweetening matter

0403

Fat

 

ISO 1211:2001|IDF 1D:1996

ISO 1736:2000|IDF 9C:1987

ISO 2450:1999|IDF 16 C:1987

ISO 7208:1999|IDF 22B:1987

ISO 8262-3:2005|IDF 124-3:2005

 

 

 

 

Protein

 

ISO 8968-1|2|3:2001|IDF 20-1|2|3:2001

 

 

 

 

Sucrose (normal content)

 

ISO 2911:2004|IDF 35:2004

 

 

 

 

Sucrose (low content)

 

 

Note 2

 

 

 

Water (acid buttermilk powder)

 

Annex XIX

 

 

 

 

Water (sweet buttermilk powder)

 

ISO 5537:2004|IDF26:2004

 

 

 

 

Solids (other products)

 

Methods approved by the competent authority

 

 

Whey, whether or not concentrated or containing added sugar or other sweetening matter; products consisting of natural milk constituents

0404

Fat

 

ISO 1736:2000|IDF 9C:1987

ISO 2450:1999|IDF 16C:1987

ISO 7208:1999|IDF 22B:1987

 

 

 

 

Protein

 

ISO 8968-1|2|3:2001|IDF 20-1|2|3:2001

 

 

 

 

Sucrose (normal content)

 

ISO 2911:2004|IDF 35:2004

 

 

 

 

Sucrose (low content)

 

 

Note 2

 

 

0404 90

Protein

 

ISO 8968 1/2 2001|IDF 20-1/2:2001

 

 

 

 

Water

 

IDF 21B:1987

 

 

 

 

Solids

 

ISO 6734:1989|IDF 15B:1991

 

 

 

 

(Concentrated products)

 

ISO 6731:1989|IDF 21B:1987

 

 

Butter and other fats derived from milk; dairy spreads

0405

Fat (if ≤ 85 % m/m)

 

ISO 17189:2003|IDF 194:2003

 

 

 

Butter

Water

 

ISO 3727-1:2001|IDF 80-1:2001

 

 

 

 

SNF

 

ISO 3727-2:2001|IDF 80-2:2001

 

 

 

 

NaCl

 

ISO 15648:2004|IDF 179:2004

 

 

 

 

Fat (if > 99 % m/m)

 

IDF 24:1964

 

 

Butteroil

 

Water (if fat < 99 % m/m)

 

ISO 5536:2002|IDF 23:2002

 

 

Cheese and curd

0406

Fat

 

ISO 1735:2004|IDF 5:2004

 

 

 

 

Solids

 

ISO 5534:2004|IDF 4:2004

 

 

 

 

Solids (Ricotta)

 

ISO 2920:2004|IDF 58:2004

 

 

 

 

NaCl

 

ISO 5943:2006|IDF 88:2006

 

 

 

 

Lactose

 

ISO 5765-1/2:2002|IDF 79-1/2:2002

 

Regulation (EEC) No 2658/87

Compound feedingstuffs

2309

Lactose

 

Annex XI

 

Notes to list of European Union reference methods:

Note 1: Milk fat isolation as described in ISO 1740:1991 (protection from light).

Note 2: No reference method has been established. Methods approved by the competent authority.

Note 3: Sample to be prepared according to ISO 8261:2001|IDF 122:2001.

Note 4: Incubation for 48 hours at a temperature of 55 °C, care should be taken to prevent the culture medium from drying out.

Note 5: % m/m SNF = % m/m solids — % m/m fat.

Note 6: Commission Directive 84/4/EEC.

Note 7: Commission Regulation (EC) No 2799/1999 (OJ L 340, 31.12.1999, p. 3-27).

Note 8: Commission Directive 78/633/EEC.


(1)  Without prejudice to the requirements in the specific Regulation

(2)  The minimum protein content would be 34 % per 1 September 2009.


ANNEX II

(Article 3)

EVALUATION OF COMPLIANCE OF A CONSIGNMENT WITH THE LEGAL LIMIT

1.   PRINCIPLE

In cases where detailed sampling procedures are given by the relevant legislation, these procedures are followed. In all other cases a sample of at least 3 sample units taken randomly from the consignment submitted to control is used. A composite sample may be prepared. The result obtained is compared with the legal limits by calculation of a 95 % confidence interval as 2 x standard deviation, where the relevant standard deviation depends on whether (1) the method is validated through international collaboration with values for σr and σR or (2) in the case of in-house validation, an internal reproducibility has been calculated. This confidence interval will then equate to the measurement uncertainty of the result.

2.   THE METHOD IS VALIDATED THROUGH INTERNATIONAL COLLABORATION

In this case the repeatability standard deviation σr and the reproducibility standard deviation σR have been established and the laboratory can demonstrate compliance with the performance characteristics of the validated method.

Calculate the arithmetic mean

Formula
of the n repeated measurements.

Calculate the expanded uncertainty (k = 2) of

Formula
as

Formula

If the final result x of measurement is calculated using a formula of the form x = y 1 + y 2, x = y 1y 2, x = y 1 · y 2 or x = y 1 / y 2 the usual procedures for combining standard deviations in such cases must be followed.

The consignment is judged to be not in compliance with the upper legal limit UL if

Formula
;

otherwise it is judged to be in compliance with UL.

The consignment is judged to be not in compliance with the lower legal limit LL if

Formula
;

otherwise it is judged to be in compliance with LL.

3.   IN-HOUSE VALIDATION WITH CALCULATION OF INTERNAL REPRODUCIBILITY STANDARD DEVIATION

In cases where methods not specified in this Regulation are used and precision measures have not been established an in-house validation must be carried out. Internal repeatability standard deviation sir and the internal reproducibility standard deviation siR have to be used instead of σr and σ R , resp., in the formulae for the computation of the expanded uncertainty U.

The decision rules are as under (1). However, if the consignment is judged to be not in compliance with the legal limit the measurements must be repeated with the method specified in this Regulation and the decision reached according to (1).


ANNEX III

(Article 4)

EVALUATION OF ASSESSORS AND THE RELIABILITY OF RESULTS IN SENSORY ANALYSES

The following procedures are applicable if scoring methods are used (IDF Standard 99C:1997).

A.   DETERMINATION OF THE ‘REPEATABILITY INDEX’

At least ten samples will be analysed as blind duplicates by an assessor within a period of 12 months. This will usually happen in several sessions. The results for individual product characteristics are evaluated using the following formula:

Formula

where:

w1

:

repeatability index

xi1

:

score for the first evaluation of sample xi

xi2

:

score for the second evaluation of sample xi

n

:

number of samples

The samples to be evaluated should reflect a broad quality range. wI should not exceed 1,5 (5-point scales).

B.   DETERMINING THE ‘DEVIATION INDEX’

This index should be used to check whether an assessor uses the same scale for quality evaluation as an experienced group of assessors. The scores obtained by the assessor are compared with the average of the scores obtained by the assessor group.

The following formula is used for the evaluation of results:

Formula

where:

xi1; xi2

:

see section (A)

Formula

;

Formula

:

average score of the assessor group for the first and second evaluation respectively of sample xi

n

:

number of samples (at least 10 per 12 months).

The samples to be evaluated should reflect a broad quality range. DI should not exceed 1,5 (5-point scales).

Member States must notify any difficulties encountered when applying this procedure.

Where individual assessors are found to exceed the 1,5 limit for Deviation or Repeatability indices, the Official authority expert/s must perform one or more random ‘Re-performance’ checks on samples graded by them over the next few weeks, or perform one or more ‘Accompanied’ checks with those assessors. Close monitoring is necessary to decide whether to retain their services. Findings should be documented and retained as proof of follow up action.

C.   COMPARISON OF THE RESULTS OBTAINED IN DIFFERENT REGIONS OF A MEMBER STATE AND IN DIFFERENT MEMBER STATES

Where applicable, a test must be organised at least once per year to compare the results obtained by assessors from different regions. If significant differences are observed, the necessary steps should be taken to identify the reasons and arrive at comparable results.

Member States may organise tests to compare the results obtained by their own assessors and by assessors from neighbouring Member States. Significant differences should lead to an in-depth investigation with the aim of arriving at comparable results.

Member States should notify the Commission of the results of these comparisons.


ANNEX IV

(Article 4)

SENSORY EVALUATION OF BUTTER

1.   SCOPE

The purpose of this procedure for sensory evaluation of butter is to provide a uniform method applicable in all Member States.

Refer to the current IDF International Standard for Milk and Milk Products, IDF 99 — Parts 1, 2, 3 on Sensory Evaluation, for further detail.

2.   DEFINITIONS

‘Sensory evaluation’ (assessment) means the examination of the attributes of a product by the sense organs.

‘Panel’ means a group of selected assessors working, during the assessment, without intercommunication, and without influencing one another.

‘Assessor’ is defined as someone chosen for his/her ability to perform a sensory test. This type of assessor may have limited experience.

‘Expert Assessor’ is defined as someone with a high degree of sensory sensitivity and experience of sensory methodology, who is able to make consistent and reliable sensory assessments of various products. This type of assessor will have a good long term sensory memory.

‘Scoring’ means sensory evaluation by a panel, using a numerical scale. A nomenclature of defects must be used.

‘Grading’ means a quality classification which is performed on the basis of scoring.

‘Control documents’: documents used to record the individual scores for each attribute and the final grade of the product. (This document may also be used to record chemical composition.)

3.   TEST ROOM

Refer to ISO 8589 and ISO/DIS 22935-2 | IDF 99-2 par 7 for more details.

Precautions must be taken in order that the assessors in the test room are not influenced by external factors.

The test room must be free from foreign odours and easy to clean. The walls must be of a light colour and non reflective.

The test room and its lighting must be such that the properties of the products to be scored are not affected.

The room must be equipped with appropriate thermostatic control to enable a constant temperature of butter to be maintained. Butter should have a temperature of 12 °C (±2 °C) at the time of grading.

4.   SELECTION OF ASSESSORS

An assessor must be familiar with butter products and be competent to carry out sensory grading. His/her competence should be monitored on a regular basis (at least once a year) by the competent authority.

4.1.   ISO/DIS 22935-1 | IDF 99-1 par 4 (recruitment) and par 5.1 should be consulted for details on general requirements and screening tests which may be used prior to official use of a new assessor.

It is essential that training is ongoing and general sessions should be held on a regular basis. Refer to ISO 8586-1 for information on panel training.

4.2.   Initial training should cover the following:

general theory and practical importance of sensory evaluation,

methods, scales and description of sensory impressions,

detection and recognition of sensory attributes and specific sensory terms,

background training on the manufacture of butter,

validated references and samples to help the assessor to identify specific flavours and flavour intensity within the product.

5.   REQUIREMENTS FOR THE PANEL

The number of assessors in the panel should be uneven, the minimum number being three. The majority must be employees of the competent authority or authorised persons not employed by the dairy industry.

A panel Leader shall be responsible for the entire procedure and may participate in the panel.

A number of factors must be taken into account before evaluation in order to obtain optimal performances from the subjects:

subjects must not be suffering from an illness which could affect their performance. In such a case, the assessor concerned should be replaced on the panel by another,

subjects must be on time to take part in the evaluation and make sure that they have enough time to make their evaluation,

subjects must not use strong-smelling substances like perfume, after-shave lotion, deodorant, etc. and should avoid eating strong-flavoured (e.g. highly spiced) food, etc.,

subjects may not smoke, eat or drink anything other than water during the half hour before the evaluation.

6.   PERFORMANCE

All Assessors should participate in regular sensory evaluation panels to maintain their competence. The frequency will depend on the volume and throughput of butter, and where possible, should be at least one panel per month.

Senior Assessors should also participate in a number of panels each year, and where possible, at least once per quarter.

7.   SAMPLING AND PREPARATION OF THE SAMPLE

It is essential that the identity of the samples is concealed during the assessment so that any possible bias is avoided. The samples should be coded.

This should be organized prior to the evaluation. Requirement for temperature of butter during its transportation to the test room should be set (6 °C ± 2 °C).

When the sensory evaluation is carried out at a cold store, the sample is taken using a butter trier. If the sensory evaluation is carried out at another location other than the cold store, then at least a 500 g sample should be taken. During the evaluation, the butter should have the temperature of 12 °C (±2 °C) (refer: in ISO/DIS 22935-2 | IDF 99-2 the evaluation temperature of butter is 14 °C ± 2 °C). Large deviations should be avoided at all cost.

8.   ASSESSMENT OF THE VALUE OF EACH ATTRIBUTE

8.1.   The sensory evaluation is to be carried out in relation to the following three attributes: appearance, consistency and flavour:

‘Appearance’ involves the following features: colour, visible purity, absence of physical contamination, absence of mould growth and uniformity of water dispersion. Water dispersion is tested according to IDF-Standard 112A/1989.

‘Consistency’ involves the following features: Body, texture and firmness. Spreadability may be monitored using physical means should an Individual Member State so wish in order to satisfy customer requirements. The Commission may decide to harmonise methodology in the future.

‘Body’ is the term which refers to the cohesiveness of the product as it is being consumed. It is normally associated with firmness and spreadability, and should be uniform throughout the product. It is closely related to texture and is the ability of the product to stand up under its own weight. It is indicated by resistance during cutting and can be measured mechanically and by mouthfeel and fingerfeel.

‘Flavour’ is the characteristic as perceived in the mouth, predominantly by the taste buds of the tongue.

‘Aroma’ is the characteristic as perceived by the nose and sense of smell.

A significant deviation from the recommended temperature prevents a reliable evaluation of consistency and flavour. The temperature is of paramount importance.

Grading of butter must be deferred if the temperature is outside the recommended band.

8.2.   Each attribute has to be sensory evaluated separately. The scoring has to be done according to table 1.

8.3.   It may be desirable for the assessors to score together, before starting the assessment, one or more reference samples for appearance, consistency and flavour, in order to achieve uniformity.

8.4.   Scoring for acceptance is as follows:

Refer to part 7 — Nomenclature, and description of criteria applicable to points, when scoring.

 

Maximum

Required

Appearance

5

4

Consistency

5

4

Flavour/aroma

5

4

Where the required score is not obtained, a description of the defect has to be given.

The score given by each assessor for each attribute must be recorded in the control document.

The product is accepted or rejected on the basis of a majority decision.

Cases where differences between the individual scoring for each attribute are wider than adjacent points should not occur frequently (not more than once per 20 samples). Otherwise the competence of the panel should be checked by the panel leader.

9.   SUPERVISION

A panel leader who must be an official employee of the competent authority and may be a member of the panel must be generally responsible for the entire procedure. He/she must record the individual scores for each attribute in the control document and certify whether the product is accepted or rejected.

10.   NOMENCLATURE

Refer to the appended table 2.

11.   REFERENCE

FIL-IDF 99C:1997 Sensory evaluation of dairy products by scoring — Reference method

ISO/DIS 22935 | IDF 99 International Standard for Milk and Milk Products — Sensory analysis — Parts 1-3

ISO 8586-1 Sensory analysis — General guidance for selection, training and monitoring of assessors — Part 1

ISO 8589 Sensory analysis — General guidance for the design of test rooms

FIL-IDF 112A:1989 Butter — Determination of water dispersion value

Table 1

Butter scoring

Appearance

Consistency

Flavour + aroma

Points

No (1)

Remarks

Points (quality class)

No (1)

Remarks

Points (quality class)

No (1)

Remarks

5

 

Very good

ideal type

highest quality

(equal dry)

5

 

Very good

ideal type

highest quality

(well spreadable)

5

 

Very good

ideal type

highest quality

(absolutely pure finest aroma)

4

 

Good  (2)

no evident defects

4

17

18

Good  (2)

hard

soft

4

 

Good  (2)

no evident defects

3

1

2

3

4

5

6

7

8

Fair (slight defects)

loose (free), moisture

not uniform, two coloured

streaky

mottled, marbled

speckled

oil separation

overcoloured

weak, open texture

3

14

15

16

17

18

Fair (slight defects)

short, brittle, crumbly

pasty, doughy, greasy

sticky

hard

soft

3

21

22

25

27

33

34

35

Fair (slight defects)

unclean

foreign flavour

acid

cooked flavour, scorched flavour

feed flavour

coarse, bitter

oversalted

2

1

3

4

5

6

10

11

12

Poor (evident defects)

loose (free) moisture

streaky

mottled, marbled

speckled

oil separation

foreign matter

mouldy

undissolved salt

2

14

15

16

17

18

Poor (evident defects)

short, brittle, crumbly

pasty, doughy, greasy

sticky

hard

soft

2

21

22

23

25

32

33

34

35

36

38

Poor (evident defects)

unclean

foreign flavour

stale

acid

oxidized flavour, metallic flavour

feed flavour

coarse, bitter

oversalted

musty-flat, putrid

chemical flavour

1

1

3

4

5

6

7

9

10

11

12

Very poor (strong defects)

loose (free) moisture

streaky

mottled, marbled

speckled

oil separation

overcoloured

granular

foreign matter

mouldy

undissolved salt

1

14

15

16

17

18

Very poor (strong defects)

short, brittle, crumbly

pasty, doughy, greasy

sticky

hard

soft

1

22

24

25

26

28

29

30

31

32

34

35

36

37

38

Very poor (strong defects)

foreign flavour

cheesy, lactic cheese flavour

acid

yeasty

mould flavour

rancid

oily, fishy

tallowy

oxidized flavour, metallic flavour

coarse, bitter

oversalted

musty-flat, putrid

malty

chemical flavour


Table 2

Table of butter defects

I.

Appearance

1.

loose (free), moisture

2.

not uniform, two coloured

3.

streaky

4.

mottled, marbled

5.

speckled

6.

oil separation

7.

overcoloured

8.

weak (open texture)

9.

granular

10.

foreign matter

11.

mouldy

12.

undissolved salt

II.

Consistency

14.

short, brittle, crumbly

15.

pasty, doughy, greasy

16.

sticky

17.

hard

18.

soft

III.

Flavour and aroma

20.

without flavour

21.

unclean (3)

22.

foreign flavour

23.

stale

24.

cheesy, lactic cheese flavour

25.

acid

26.

yeasty

27. (a)

cooked flavour

(b)

scorched flavour

28.

mouldy flavour

29.

rancid

30.

oily, fishy

31.

tallowy

32. (a)

oxidized flavour

(b)

metallic flavour

33.

feed flavour

34.

coarse, bitter

35.

oversalted

36.

musty-flat, putrid

37.

malty

38.

chemical flavour


(1)  Table 2.

(2)  The defects mentioned under ‘good’ are only very small deviations from the ideal type.

(3)  This designation should be used as seldom as possible and only when the defect cannot be described more accurately.


ANNEX V

(Article 5)

DETERMINATION OF THE CONTENT OF ENANTHIC ACID TRIGLYCERIDE IN BUTTER, BUTTER-OIL AND CREAM BY GAS CHROMATOGRAPHIC ANALYSIS OF TRIGLYCERIDES

1.   SCOPE

This method lays down a method for the determination of the content of the triglyceride of enanthic acid in butter-oil, butter and cream.

2.   TERMS AND DEFINITION

Enanthic acid content: content of the triglyceride of enanthic acid determined by the procedure specified in this method.

Note: The enanthic acid content is expressed in kg per ton of product for butter-oil and butter, and it is expressed in kg per ton of milk fat for cream.

3.   PRINCIPLE

Milk fat is extracted from the different products according to ISO 14156 | IDF 172:2001. The quantitative determination of the content of the triglyceride of enanthic acid in the extracted fat is determined by capillary gas chromatography (GC). The result obtained for the sample is evaluated by reference to the triglyceride of caproic acid as internal standard.

Note: Tributyrin has also been found to be a satisfactory internal standard.

4.   REAGENTS

Use only reagents of recognized analytical grade.

4.1.   n-Hexane

4.2.   Standard triglyceride of caproic acid, at least 99 % pure

4.3.   Standard triglyceride of enanthic acid, at least 99 % pure

4.4.   Anhydrous sodium sulfate (Na2SO4).

5.   APPARATUS

Usual laboratory equipment and particularly the following:

5.1.   Analytical balance precise at 1 mg

5.2.   Volumetric flasks, of capacities 10 ml and 20 ml

5.3.   Tubes for centrifuge, of capacity 30 ml

5.4.   Rotary evaporator

5.5.   Oven, capable of being maintained at a temperature of 50 °C ± 5 °C

5.6.   Filter paper, medium porosity, of diameter about 15 cm

Gas chromatography equipment

5.7.1.   Gas chromatograph equipped with a split/splitless or on-column injector and a flame ionization detector (FID)

GC column, with a stationary phase which has successfully employed to perform triglyceride separation (100 % dimethylpolysiloxane or 5 % phenyl-95 % methylpolysiloxane). Select the stationary phase, the column length (between 4 m and 15 m), the internal diameter (between 0,22 mm and 0,50 mm) and the film thickness (0,12 μm or more) taking into account the laboratory experience and the injection system applied. In any case the selected column shall produce both a complete separation between the solvent peak and the triglyceride of caproic acid and a baseline resolution between triglyceride of caproic and enanthic acid peaks. Examples of applicable conditions are listed below.

5.7.2.1.   Example of applicable conditions using a split injector:

Carrier gas: helium

Column head pressure: 100 KPa

Column: 12 m length, 0,5 mm internal diameter, 0,1 μm film thickness fused silica column

Stationary phase: 100 % dimethylpolysiloxane or 5 % phenyl-95 % dimethylpolysiloxane (for ex. HT5)

Column temperature: initial temperature of 130 °C, maintained for 1 min, raised at a rate of 20 °C/min up to 260 °C and then raised at a rate of 30 °C/min up to 360 °C; maintain 10 mn at 360 °C

Detector temperature: 370 °C

Injector temperature: 350 °C

Split ratio 1:30

Amount of sample injected: 1 μl.

5.7.2.2.   Example of applicable conditions using an on-column injector:

Carrier gas: hydrogen (constant flow system)

Column head pressure: 89 kPa

Column: 4 m length, 0,32 mm internal diameter, 0,25 μm film thickness, fused silica column

Stationary phase: 5 % phenyl, 95 % dimethylpolysiloxane

Column temperature: initial temperature of 60 °C, maintained for 2 min, raised at a rate of 35 °C/min up to 340 °C, maintained at this temperature for 5 min

Detector temperature: 350 °C

Amount of sample injected: 1 μl

5.8.   Injection syringe, of capacity 5 μl.

6.   SAMPLING

It is important that the laboratory receives a sample which is truly representative and has not been damaged or changed during transport or storage.

Sampling is not part of the method specified in this International Standard. A recommended sampling method is given in IDF: standard 50C:1995 or ISO 707-1997 — Milk and milk products — Methods of sampling.

7.   PROCEDURE

7.1.   Preparation of the test sample and test portion

Proceed according to ISO 14156 | IDF 172:2001

7.1.1.   Butter-oil, Butter

7.1.1.1.   Melt 50 g to 100 g of test sample in the oven (5.5)

7.1.1.2.   Place 0,5 g to 1,0 g of anhydrous sodium sulfate (5.4) in a folded filter paper

7.1.1.3.   Filter the fat through the filter paper containing anhydrous sodium sulfate collecting the filtrate in a beaker maintained in the oven (5.5). When decanting the melted butter onto the filter paper, take care that no serum is transferred

7.1.2.   Cream

7.1.2.1.   Bring the test sample to a temperature of 20 °C ± 2 °C

7.1.2.2.   Mix or stir the sample thoroughly

7.1.2.3.   Dilute a suitable amount of test sample so as to obtain 100 ml of test portion with a mass fraction of fat of approximately 4 %

7.1.2.4.   Proceed as with raw milk and homogenized milk (see ISO 14156 | IDF 172:2001, §8.3) to extract the fat from the cream

7.1.2.5.   Weigh in a 10 ml volumetric flask (5.2), to the nearest 1 mg, 1 g of the extracted fat. Add 1 ml of the solution 7.2.2. Complete to 10 ml with n-hexane (4.1) and homogenise

7.1.2.6.   Introduce 1 ml of the solution 7.1.1.2 in a 10 ml volumetric flask (5.2) and dilute to 10 ml with n-hexane (4.1)

7.2.   Preparation of the calibration standards

7.2.1.   Dissolve 100 mg of the triglyceride of enanthic acid (4.3) in 10 ml of n-hexane (4.1)

7.2.2.   Dissolve 100 mg of the triglyceride of caproic acid (4.2) in 10 ml of n-hexane (4.1)

7.2.3.   Introduce 1 ml of the solution 7.2.2 in a 10 ml volumetric flask (5.2). Complete to 10ml with n-hexane (4.1)

7.2.4.   Introduce 1 ml of the solution 7.2.1 and 1 ml of the solution 7.2.2 in a 10 ml volumetric flask (5.2). Complete to 10 ml with n-hexane (4.1)

7.2.5.   Introduce 1 ml of the solution 7.2.4 in a 10 ml volumetric flask (5.2) and complete to 10 ml with n-hexane (4.1)

7.3.   Chromatographic determination

7.3.1.   Inject 1 μl of the standard solution 7.2.5 twice

7.3.2.   Inject 1 μl of each sample solution

Note: If the on column injector system is adopted an increased dilution should be applied both to the standard and sample solutions.

7.3.3.   Repeat the operation 7.3.1 every 3 samples in order to bracket samples between duplicate standard injections. Results are based upon the mean average response factors from the standard chromatograms.

8.   CALCULATION OF RESULTS

For each chromatogram, integrate the area of the peaks associated with the triglycerides of enanthic acid and caproic acid.

Follow those instructions for each bracketed sequence i.e. for a set of bracketed samples, the standard injected twice immediately before them is STD1 and the standard injected twice immediately after them is STD2.

8.1.   Calibration

8.1.1.   Calculate the response factor for each duplicate of STD1, Rf1(a) and Rf1(b)

Rf1 (a) or (b) = (Peak area for caproic acid triglyceride/Peak area for enanthic acid triglyceride) × 100

Calculate the mean average response factor, Rf1

Rf1 = (Rf1(a) + Rf1(b)) / 2

8.1.2.   Similarly, calculate the mean average response factor STD2, Rf2

8.1.3.   Calculate the mean average response factor, Rf

Rf = (Rf1 + Rf2) /2

8.2.   Test samples

For each sample chromatogram obtained between STD1 and STD2, calculate the enanthic acid content, C (kg/t):

C = (Peak area for enanthic acid triglyceride × Rf × 100)/(Peak area for caproic acid triglyceride × Wt × 1 000)

where:

Wt = weight of fat taken (g),

100 = dilution volume for sample,

1 000 = conversion factor (for μg/g to kg/t)

For butter samples, take the fat content of butter into account and calculate a corrected concentration value, Cbutter (kg/t of butter)

Cbutter = Cfat × F

where F is the fat content of butter.

9.   PRECISION

Details of an interlaboratory test on butter in accordance with ISO 5725-1 and ISO 5725-2 on the precision method are shown in (12.).

The values for repeatability and reproducibility limit are expressed for the 95 % probability level and may not be applicable to concentration ranges and matrices other than those given.

9.1.   Repeatability

The absolute differences between two individual single test results, obtained with the same method on identical test material in the same laboratory by the same operator using the same equipment within a short interval of time, will in not more than 5 % of cases be greater than 0,35 kg/t.

9.2.   Reproducibility

The absolute differences between two individual single test results, obtained with the same method on identical test material in different laboratories with different operators using different equipment will in not more than 5 % of cases be greater than 0,66 kg/t.

10.   TOLERANCE LIMITS: LOWER LIMITS (CASE OF INSUFFICIENT QUANTITIES)

10.1.    Three samples must be taken from the traced product in order to check on the correct tracing of the product

10.2.   Butter and concentrated butter

10.2.1.   The incorporation rate is 11 kg of at least 95 % pure enanthic acid triglyceride per tonne of butter, i.e. 10,45 kg/t

10.2.2.   The results of three samples obtained from the analysis of the product are used to check the rate and the homogeneity of tracer incorporation and the lowest of these results is compared with the following limits:

9,51 kg/t (95 % of the minimum incorporation rate of 95 % pure enanthic acid triglyceride, single determination),

6,89 kg/t (70 % of the minimum incorporation rate of 95 % pure enanthic acid triglyceride, single determination),

The tracer concentration of the sample giving the lowest result is used in conjunction with interpolation respectively between 9,51 kg/t and 6,89 kg/t.

10.3.   Cream

10.3.1.   The incorporation is 10 kg of at least 95 % pure enanthic acid triglyceride per tonne of milk fat, i.e. 9,50 kg/t traced milk fat

10.3.2.   The results of the three samples obtained from the analysis of the product are used to check the rate of the homogeneity of tracer incorporation and the lowest of these results is compared with the following limits:

8,60 kg/t (95 % of the minimum incorporation rate of 95 % pure enanthic acid triglyceride, single determination),

6,23 kg/t (70 % of the minimum incorporation rate of 95 % pure enanthic acid triglyceride, single determination),

The tracer concentration of the sample giving the lowest result is used in conjunction with interpolation respectively between 8,60 kg/t and 6,23 kg/t.

11.   TOLERANCE LIMITS: UPPER LIMITS (CASE OF EXCEEDING QUANTITY BY MORE THAN 20 %)

11.1.    Three samples must be taken from the traced product in order to check on the correct tracing of the product

11.2.   Butter and concentrated butter

11.2.1.   The results of three samples obtained from the analysis of the product are used to check the rate and the homogeneity of tracer incorporation and the mean of these results is compared with the following limits:

Upper limit is 12,96 kg/t

11.3.   Cream

11.3.1.   The results of three samples obtained from the analysis of the product are used to check the rate and the homogeneity of tracer incorporation and the mean of these results is compared with the following limits:

Upper limit is 11,82 kg/t.

12.   ADDITIONAL INFORMATION: STATISTICAL ANALYSIS OF RESULTS ON THE DETERMINATION OF TRIENANTOATE IN BUTTERFAT BY TRIGLYCERIDE ANALYSIS

Four collaborative trials have been carried out to determine the trienantoate content in traced butter.

Nine laboratories participated to the 1st ring test and no specifications were provided about the analytical methods to use:

10 laboratories participated to the 2nd ring test and 4 different methods were applied:

Quantification of methylheptanoate by using n-nonane or methylnonanoate as internal standard

Quantification of trienantoate by using tricaproate as internal standard

Quantification of methylheptanoate by using a calibration sample/mixture

Quantification of methylheptanoate by using a calibration mixture.

Moreover, if FAME were analysed, two different methylation procedures were used (De Francesco and Christopherson & Glass).

Due to the results obtained, two methods were chosen to perform the 3rd ring test:

Quantification of methylheptanoate by using n-nonane or methylnonanoate as internal standard

Quantification of trienantoate by using tricaproate as internal standard.

The results of 7 labs showed that the FAME method produced a higher variability and consequently it was decided to use only the determination of trienantoate as triglyceride following the procedure of the q Quantification of trienantoate by using tricaproate as internal standard. Moreover the triglyceride analysis has to be carried out by capillary column.

In the 4th ring test four samples (A, B, C, D) were circulated and nine laboratories provided results (Tables 1-2).

Two laboratories (DE and UE) analysed the samples by using FAME method.

Due to the reduced number of laboratories, the Statistical calculation has been performed both on the complete set (Figures 1-2) of data including FAME results and on the data obtained from TG analysis.

Tests for outliers:

sample A. Dixon, Cochran and Grubbs tests at levels 1 and 5 %, showed one laboratory outlier.

sample B. Grubbs test at level 5 % showed one laboratory outlier.

sample C. Dixon and Grubbs tests at levels 1 and 5 %, showed one laboratory outlier.

sample D. Dixon and Grubbs tests at levels 1 end 5 %, showed one laboratory outlier.

The outlier has been excluded from the calculation.

It is worth noting that the results obtained by FAME method were never considered as outliers by the tests applied.

Precision parameters

Tables 1 and 2 report the results of all the laboratories and the precision parameters calculated on an acceptable number (8) of labs but, unfortunately not deriving from the same analytical method.

Tables 3 and 4 report the results deriving only from TG method and the corresponding precision parameters. The acceptance of these parameters is subjected to the acceptance of the low number of laboratories (6).

Figures 2 and 3 show the trend of Sr and SR calculated on the 4 samples of the 2 data set described above.

Table 5 reports the Sr and SR values together with the corresponding pooled values and overall r and R parameters.

Finally the Critical Difference at 95 % of probability level has been calculated.

Table 1

Statistical Results of TG + FAME* methods

Sample A

 

R1

R2

Mean

N. of labs retained after eliminating outliers

8

RENNES

FR1

11,0

11,1

11,1

N. of outliers

1

RIKILT

NL

11,2

11,2

11,2

Outliers

ZPLA

DE*

11,6

11,8

11,7

Mean value

11,3

ADAS

GB

11,4

11,2

11,3

True value

11,0

CNEVA

FR2

11,4

11,4

11,4

Repeatability standard deviation (Sr)

0,09

LODI

IT

11,1

11,3

11,2

Repeatability relative sd (RSDr%)

0,80

EELA

FI

11,3

11,2

11,3

Repeatability r (95 %)

0,26

ISPRA

UE*

11,0

11,0

11,0

Relative Repeatability r %

2,24

D.V.F.A.

DK

13,3

11,8

12,6

Reproducibility standard deviation (SR)

0,23

 

 

 

 

 

Reproducibility relative sd (RSDR%)

2,04

 

 

 

 

 

Reproducibility R (95 %)

0,84

 

 

 

 

 

Relative Reproducibility R %

5,71

Sample B

 

R1

R2

Mean

N. of labs retained after eliminating outliers

8

RENNES

FR1

12,7

12,8

12,8

N, of outliers

1

RIKILT

NL

13,5

13,3

13,4

Outliers

DK

ZPLA

DE*

14,0

13,8

13,9

Mean value

13,4

ADAS

GB

13,4

13,5

13,5

True value

13,5

CNEVA

FR2

13,3

13,4

13,4

Repeatability standard deviation (Sr)

0,14

LODI

IT

13,9

13,5

13,7

Repeatability relative sd (RSDr%)

1,04

EELA

FI

13,4

13,2

13,3

Repeatability r (95 %)

0,40

ISPRA

UE*

13,2

13,3

13,3

Relative Repeatability r %

2,91

D.V.F.A.

DK

14,1

14,8

14,5

Reproducibility standard deviation (SR)

0,35

 

 

 

 

 

Reproducibility relative sd (RSDR%)

2,61

 

 

 

 

 

Reproducibility R (95 %)

0,99

 

 

 

 

 

Relative reproducibility R %

7,31


Table 2

Statistical Results of TG + FAME* methods

Sample C

 

R1

R2

Mean

N. of labs retained after eliminating outliers

8

RENNES

FR1

8,9

9,2

9,1

N. of outliers

1

RIKILT

NL

9,2

9,3

9,3

Outliers

DK

ZPLA

DE*

9,2

9,4

9,3

Mean value

9,3

ADAS

GB

9,5

9,3

9,4

True value

9,3

CNEVA

FR2

9,4

9,4

9,4

Repeatability standard deviation (Sr)

0,14

LODI

IT

9,2

9,5

9,4

Repeatability relative sd (RSDr%)

1,50

EELA

FI

9,4

9,6

9,5

Repeatability r (95 %)

0,40

ISPRA

UE*

9,4

9,3

9,4

Relative Repeatability r %

4,20

D.V.F.A.

DK

10,7

10,9

10,8

Reproducibility standard deviation (SR)

0,17

 

 

 

 

 

Reproducibility relative sd (RSDR%)

1,82

 

 

 

 

 

Reproducibility R (95 %)

0,47

 

 

 

 

 

Relative Reproducibility R %

5,10

Sample D

 

R1

R2

Mean

N. of labs retained after eliminating outliers

8

RENNES

R1

1,6

1,6

1,6

N. of outliers

1

RIKILT

NL

2,1

2,1

2,1

Outliers

DK

ZPLA

DE*

2,3

2,3

2,3

Mean value

2,1

ADAS

GB

2,1

2,2

2,2

True value

2,1

CNEVA

FR2

2,1

2,1

2,1

Repeatability standard deviation (Sr)

0,08

LODI

IT

2,2

1,9

2,1

Repeatability relative sd (RSDr%)

3,81

EELA

FI

2,3

2,3

2,3

Repeatability r (95 %)

0,22

ISPRA

UE*

2,3

2,3

2,3

Relative Repeatability r %

10,67

D.V.F.A.

DK

3,4

2,9

3,2

Reproducibility standard deviation (SR)

0,24

 

 

 

 

 

Reproducibility relative sd (RSDR%)

11,43

 

 

 

 

 

Reproducibility R (95 %)

0,67

 

 

 

 

 

Relative Reproducibility R %

32,00


Table 3

Statistical Results of TG + FAME* methods

Sample A

 

R1

R2

Mean

N. of labs retained after eliminating outliers

6

RENNES

FR1

11,0

11,1

11,1

N. of outliers

1

RIKILT

NL

11,2

11,2

11,2

Outliers

ADAS

GB

11,4

11,2

11,3

Mean value

11,2

CNEVA

FR2

11,4

11,4

11,4

True value

11,0

LODI

IT

11,1

11,3

11,2

Repeatability standard deviation (Sr)

0,09

EELA

FI

11,3

11,2

11,3

Repeatability relative sd (RSDr%)

0,80

D.V.F.A.

DK

13,3

11,8

12,6

Repeatability r (95 %)

0,25

 

 

 

 

 

Relative Repeatability r %

2,24

 

 

 

 

 

Reproducibility standard deviation (SR)

0,13

 

 

 

 

 

Reproducibility relative sd (RSDR%)

1,16

 

 

 

 

 

Reproducibility R (95 %)

0,36

 

 

 

 

 

Relative Reproducibility R %

3,25

Sample B

 

R1

R2

Mean

N. of labs retained after eliminating outliers

6

RENNES

FR1

12,7

12,8

12,8

N. of outliers

1

RIKILT

NL

13,5

13,3

13,4

Outliers

ADAS

GB

13,4

13,5

13,5

Mean value

13,3

CNEVA

FR2

13,3

13,4

13,4

True value

13,5

LODI

IT

13,9

13,5

13,7

Repeatability standard deviation (Sr)

0,15

EELA

FI

13,4

13,2

13,3

Repeatability relative sd (RSDr%)

1,13

D.V.F.A.

DK

14,1

14,8

14,5

Repeatability r (95 %)

0,42

 

 

 

 

 

Relative Repeatability r %

3,16

 

 

 

 

 

Reproducibility standard deviation (SR)

0,33

 

 

 

 

 

Reproducibility relative sd (RSDR%)

2,48

 

 

 

 

 

Reproducibility R (95 %)

0,93

 

 

 

 

 

Relative Reproducibility R %

6,94


Table 4

Statistical Results of TG method

Sample C

 

R1

R2

Mean

N. of labs retained after eliminating outliers

6

RENNES

FR1

8,9

9,2

9,1

N. of outliers

1

RIKILT

NL

9,2

9,3

9,3

Outliers

ADAS

GB

9,5

9,3

9,4

Mean value

9,3

CNEVA

FR2

9,4

9,4

9,4

True value

9,3

LODI

IT

9,2

9,5

9,4

Repeatability standard deviation (Sr)

0,15

EELA

FI

9,4

9,6

9,5

Repeatability relative sd (RSDr%)

1,61

D.V.F.A.

DK

10,7

10,9

10,8

Repeatability r (95 %)

0,42

 

 

 

 

 

Relative Repeatability r %

4,51

 

 

 

 

 

Reproducibility standard deviation (SR)

0,19

 

 

 

 

 

Reproducibility relative sd (RSDR%)

2,04

 

 

 

 

 

Reproducibility R (95 %)

0,53

 

 

 

 

 

Relative Reproducibility R %

5,71

Sample D

 

R1

R2

Mean

N, of labs retained after eliminating outliers

6

RENNES

FR1

1,6

1,6

1,6

N. of outliers

1

RIKILT

NL

2,1

2,1

2,1

Outliers

DK

 

 

 

 

 

Mean Value

2,1

ADAS

GB

2,1

2,2

2,2

True value

2,1

CNEVA

FR2

2,1

2,1

2,1

Repeatability standard deviation (Sr)

0,09

LODI

IT

2,2

1,9

2,1

Repeatability relative sd (RSDr%)

4,29

EELA

FI

2,3

2,3

2,3

Repeatability r (95 %)

0,26

D.V.F.A.

DK

3,4

2,9

3,2

Relative Repeatability r %

12,01

 

 

 

 

 

Reproducibility standard deviation (SR)

0,25

 

 

 

 

 

Reproducibility relative sd (RSDR%]

11,90

 

 

 

 

 

Reproducibility R (95 %)

0,69

 

 

 

 

 

Relative Reproducibility R %

33,32


Table 5

Repeatability and reproducibility (with FAME)

 

No of labs

Outlier

Repeatability

Sr (95 %)

Reproducibility

SR (95 %)

Sample A

8

1

0,09

0,23

Sample Β

8

1

0,14

0,35

Sample C

8

1

0,14

0,17

Sample D

8

1

0,08

0,24

Pooled value

 

 

0,116

0,256

 

 

 

r

R

Pooled value* 2,8

 

 

0,324

0,716

CrD95 =0,40

Minimum purity stated for trienantoate = 95 %

Minimum limit stated for trienantoate in butterfat = 11 kg/t

Taking the Critical Difference for a 95 % probability level into consideration, the mean of the two results shall not be less than:

 

in the case of incorporation of 95 % pure trienantoate 10,05 kg/t


Repeatability and reproducibility (without FAME)

 

No of labs

Outlier

Repeatability

Sr (95 %)

Reproducibility

SR (95 %)

Sample A

6

1

0,09

0,13

Sample B

6

1

0,15

0,33

Sample C

6

1

0,15

0,19

Sample D

6

1

0,09

0,25

Pooled value

 

 

0,124

0,237

 

 

 

r

R

Pooled value * 2,8

 

 

0,347

0,663

CrD95 = 0,36

Minimum purity stated for trienantoate = 95 %

Minimum limit stated for trienantoate in butterfat = 11 kg/t

Taking the Critical Difference for a 95 % probability level into consideration, the mean of the two results shall not be less than:

 

in the case of incorporation of 95 % pure trienantoate 10,09 kg/t.

Figure 1 (*1)

Experimental results: Sample A

Image 1

14,0

outlier

13,5

13,0

12,5

kg/t

R1

12,0

outlier

R2

mean

true

11,5

11,0

10,5

10,0

FR1

NL

DE (*)

GB

FR2

IT

FI

UE (*)

DK

labs

Experimental results: Sample B

Image 2

16,0

15,5

outlier

15,0

outlier

14,5

kg/t

R1

14,0

R2

mean

13,5

true

13,0

12,5

12,0

FR1

NL

DE (*)

GB

FR2

IT

FI

UE (*)

DK

labs

Experimental results: Sample C

Image 3

12,0

11,5

outlier

11,0

outlier

10,5

kg/t

R1

R2

10,0

mean

true

9,5

9,0

8,5

8,0

FR1

NL

DE (*)

GB

FR2

IT

FI

UE (*)

DK

labs

Experimental results: Sample D

Image 4

4,0

outlier

3,5

outlier

3,0

2,5

kg/t

R1

2,0

R2

mean

1,5

true

1,0

0,5

0,0

FR1

NL

DE (*)

GB

FR2

IT

FI

UE (*)

DK

labs

Figure 2

Repeatability and Reproducibility standard deviation at different levels (TG+FAME)

Image 5

0,4

0,3

S(r,R)

0,2

Sr

SR

0,1

0

0

2

4

6

8

10

12

14

Mean values (kg/t)

Figure 3

Repeatability and Reproducibility standard deviation at different levels (TG)

Image 6

0,35

0,3

0,25

S(r,R)

0,2

Sr

0,15

SR

0,1

0,05

0

0

2

4

6

8

10

12

14

Mean values (kg/t)

Figure 4

Example using an on-column injector