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HARMONISATION OF ANALYTICAL METHODS FOR DETERMINING INSOLUBLE IMPURITIES IN RENDERED ANIMAL FAT (‘tallow’)

EURL-AP Scientific advice and support

Final version

Authors:

M-C. Lecrenier, C. Belinchon, P. Veys and V. Baeten

May 2012

Editor :

Centre wallon de Recherches agronomiques

Service Communication

Rue de Liroux, 9

5030 Gembloux (Belgique)

Summary

Under Regulation (EC) No 1069/2009 [1] and the Commission Regulation (EU) No 142/2011 [2],

tallow has to be purified so that the maximum level of remaining total insoluble impurities does not

exceed 0.15% in weight. However EU law does not specify the method by which those insoluble

impurities are to be determined.

There are currently two main methods in use: ISO 663 method [3] with different variations and

AOCS Ca 3a-46 method [4]. The study consisted to compare both methods as well as some options

as different filters, solvents, aliquot sizes and procedure offered. The aliquot sets consisted of blank

fat and contaminated fat with sand or defatted MBM (Meat and Bone Meal).

Results indicated major difference between methods. ISO 663 method associated with Petroleum

Ether and filter crucible seems to be the best method within the context of assessment of residual

BSE risk in tallow by a best MBM recovery rate. However, critical point stays the sampling in which

it is essential to provide an efficient method adapted to the laboratory.

Keywords:

Tallow – Fat – Insoluble impurities – ISO 663 – AOCS Ca 3a-46

1. Foreword

European Union Reference Laboratories (EURL) – formerly referred to as Community Reference

Laboratories (CRL) – were created in order to ensure a high level of quality and a uniformity of the

results provided by European control laboratories. On 29 April 2004, the European Parliament and

the Council adopted the Regulation EC/882/2004 [5], improving the effectiveness of the official

food and feed controls while redefining the obligations of the relevant authorities and their

obligations in the organization of these controls.

On March 2011, the Commission Regulation EC/208/2011 [6] renewed the Walloon Agricultural

Research Centre as European Union Reference Laboratory for animal proteins in feedingstuffs

(EURL-AP, http://eurl.craw.eu). It has to develop the following priority axes:

(i) To provide National Reference Laboratories (NRLs) with detailed analytical methods, including reference methods for the network of Member State NRLs;

(ii) To coordinate application by NRLs of the methods by organizing interlaboratory studies;

(iii) To develop new analytical methods for the detection of animal proteins in feedingstuffs (light microscopy, near infrared microscopy, PCR, immunology …);

(iv) To conduct training courses for the benefit of NRL staffs from Member States and future Member States;

(v) To provide scientific and technical assistance to the European Commission, especially in cases of disputed results between Member States.

In this framework, the EURL-AP provide a scientific advice and support of the DG-Sanco’s request

regarding the testing of methods related to insoluble impurities in rendered animal fat. The present

study report is part of this activity scope.

2. Introduction

Tallow is used in animal feed, in the oleochemical industry or as a raw material for the production

of biodiesel.

The European Food Safety Authority (EFSA) Biohaz Panel [7] was invited to assess the validity of the

outcome of a quantitative assessment of residual BSE risk in tallow and to advice on how to

interpret the results of calculation in order to make an estimate of the number of potential BSE

(Cattle) and vCJD (human) case expected per year in a population. In general, the exposure levels

calculated in the case of tallow are so low that they can be regarded as minimal. The EFSA opinion

supports the Scientific Steering Committee [8] opinion that possible TSE risks associated with tallow

will result from protein impurities that may be present in the end-product.

Under Regulation (EC) No 1069/2009 [1] and the Commission Regulation (EU) No 142/2011 [2],

tallow has to be purified so that the maximum level of remaining total insoluble impurities does not

exceed 0.15% in weight. However EU law does not specify the method by which those insoluble

impurities are to be determined. Furthermore, there are different constituents of tallow impurities,

such as mechanicals impurities, mineral substances, carbohydrates, nitrogenous substances,

alkaline soaps or oxidised fatty acids, for which it is not established whether or not they are to be

included in analytical methods.

According to information received from some Member States and from the rendering sector, in

particular the European Fat Processors and Renderers Association (EFPRA), there are currently two

main methods in use, which, according to the information submitted, would be likely to lead to

different results. The first method is ISO 663 with different variations and the second one is method

Ca 3a-46 developed by the American Society of Oil Chemists (AOCS). Some rendering plants use in-

house developed methods which are not comparable to the above.

Method ISO 663 has been developed for determining the insoluble impurities content of animal

and vegetable fats and oils. The method includes soaps in the insoluble impurities content.

Method AOCS Ca 3a-46 has been developed for determining sediment in crude fat and oils. This

method excluded soaps from the analysis through the use of certain solvents.

All in-house methods are based on centrifugation. They are not derived from any of the standard

methods.

Method ISO 633 and method AOCS Ca 3a-46 present significant variations in test results.

In June 2012, the European Commission Health & Consumers Directorate-General sent a request to

the EURL-AP (cf. Annex 2) in which they asked:

(i) To assess the potential differences in performance between the analytical methods which

are currently in use and to identify an appropriate standard for analytical method, and

(ii) To provide them with the EURL-AP’s view on which constituents of tallow should be

included in the analysis.

3. Material and methods

3.1. Study steps

The study included different steps:

(i) Performance comparison of the different solvents proposed on the ISO 663 with aliquot n°1 (Table I in Annex 1);

(ii) Performance comparison of the different filters proposed on the ISO 663 with aliquot n°2 (Table II in Annex 1);

(iii) Performance comparison of ISO 663 and AOCS Ca 3a-46 methods with aliquot n°2 (Table III in Annex 1);

(iv) Performance comparison of ISO 663 and modified AOCS Ca 3a-46 methods with aliquot n°2 (Table IV in Annex 1);

(v) Performance comparison of ISO 663 and modified AOCS Ca 3a-46 methods with aliquot n°3 (Table V in Annex 1).

3.2. General principles and differences between the 2 methods

General principles can be summarised as follows:

(i) Representative sampling: the aliquot has to be obtained from the subsample received by a suitable homogenization and a reduction in size which is representative of the whole lot and intended for laboratory examination.

(ii) Filter drying: after drying in oven, filters have to be cooled to room temperature in a desiccator. Glass-fibre filter and cellulose fibre filter must be kept into a vase.

(iii) Sample and filter weighing

(iv) Dissolution with a non-polar solvent: different solvents are available.

(v) Vacuum filtration

(vi) Flask and filter rinsing: a lot of rinsing is required to remove all the impurities and fat.

(vii) Filter drying: see point (ii)

(viii) Impurities weighing

(ix) Calculation:

Insoluble impurities (%) = x 100

Gain in mass of filter

Aliquot mass

Although there are many similarities between the two standard methods, there are also major

differences (see Figure 1).

Figure 1: Major differences between ISO 663 and AOCS Ca 3a-46 methods

European (ISO 663) American (AOCS Ca 3a-46)

Aliquot mass: 20g 5g (2g in case of subsample with higher

percentage of insoluble impurities)

Solvents: N-Hexane or Petroleum Ether (40/60) Kerosene (flash point >23°C) and

Petroleum Ether

Filters:

Cellulose fibre filter (type Whatman n°42)

or Glass-fibre filter (type Whatman GF/D)

or Filter crucible (10-16µm porosity)

Gooch crucible + Glass-fibre filter (type

Whatman GF/C)

Laboratory flask: Conical flask 250 ml Unspecified

Solubilisation: 200ml solvent 50ml Kerosene

Rinsing: Hot Solvent T°max: 60°C (Volume

unspecified)

5x10ml hot kerosene (T° unspecified)+

petroleum ether (Volume unspecified)

Oven

temperature: 103°C ± 2°C (drying period unspecified) 101°C ± 1°C (drying period unspecified)

Organic impurities

determination Cellulose fibre filter incineration Unspecified

Acid oils analysis Add Kieselgur to the filter unspecified

3.3. Material

Fats can be liquid, semi-liquid or solid.

The sampling is the crucial point in the methods. To ensure homogeneity, samples have to be mixed

thoroughly. If necessary (in case of solid or semi-liquid fat), fat can be softened with gentle heating

before mixing. It is important that fat is not melted because water and impurities tend to settle to

the bottom.

As regards liquid fats, it is impossible to avoid this.

3.3.1. Primarily tests:

Two samples of 200 g of liquid fat, contaminated at 0.15% of sand, were prepared.

Different sampling treatments were applied:

(i) Shaking of the sample and immediate sampling with a pipette.

(ii) Shaking of the sample until it is nearly solid. In this way, impurities are supposed to be

homogeneously trapped in the fat. Sampling with a sampling scoops (see Figure 2).

Unfortunately, the homogeneity test showed that aliquots were heterogeneous. Fragments always

tend to segregate and to constitute local aggregates of fragments with a significant higher

concentration of fragments.

Therefore, it was decided to prepare for this study one-way aliquots synthetized with known

concentration of impurities by spiking.

3.3.2. Description of the aliquots

Three different aliquots were prepared as shown in Figure 3.

The composition of the sample set was established taking into account following considerations:

As fat, beef tallow intended for human consumption bought from a supermarket was used. It was

melted at 50°C. This type of fat can contain a maximum level of insoluble impurities of 0.02%. For

the aliquot n°1, fat was first filtered. For the other steps, this percentage level was considered as

negligible as regards to the utilisation of the same fat for all the aliquots.

Impurities concentration closed to 0.15% which is the maximal concentration allowed in tallow.

Figure 2: Fat sampling

MBM was selected as impurities for the aliquot n°3 to assess the performance of the methods

with different types of insoluble impurities. A pure porcine meat and bone meal, which was

defatted by Folch method and sieved to recover the fraction between 500 µm and 125 µm, was

used. The Folch method is based on the extraction of fat using a 2:1 mixture of

chloroform/methanol. It consists of a very polar mixture of solvents so that this mixture extracts

all the lipids.

Figure 3: Composition of aliquots set used in the study

Aliquot Material

1 Blank

2 Blank + 0.15% sand

3 Blank + 0.15% defatted MBM

3.4. Statistical analysis

For each step, the same statistical procedure was applied:

(i) Normality test

(ii) Equality of variances

(iii) Means comparison

The different tests used are summarized in Figure 4:

Figure 4: Statistical tests used for the different study steps (see 3.1)

Step n°1 Step n°2 Step n°3 Step n°4 Step n°5

Normality test S-W S-W S-W S-W S-W A-D A-D A-D A-D A-D

Equality of variances

Levene Levene Levene Levene Levene

Means comparison

Tukey (p.test)

Tukey (p. test)

Tukey (p. test)

K-W (non-p. test)

Tukey (p. test)

(Legend: S-W = Shapiro-Wilk, A-D = Anderson-Darling, K-W = Kruskal-Wallis, p. test = parametric test, non-p. test = non-parametric test)

4. Results

4.1. Performance comparison of the different solvents proposed on the ISO 663 with aliquot

n°1

In this case, blank fat was used.

The influence of solvents on the percentage of impurities was assessed (see Figure 5). No difference

between filter weights before and after filtration (impurities percentages = 0%) has therefore to be

measured in this case (blank fat). An increase of this percentage shows an incomplete dissolution of

the fats which are not able to pass through the filter.

Figure 5: Boxplot: percentage of impurities by solvent with the ISO 663 method

The means of impurities percentages were greater than zero. These small percentages (less than

2*10-4 %) can be explained by small variations of the filter’s weights due to their hydrophilic

proprieties. This observation confirms the importance of the filters desiccation.

The multiple comparison of means showed that there was no significant difference between the

two solvents.

Both Petroleum Ether and N-Hexane can be used as a solvent. However, due to the higher toxicity

of N-Hexane, Petroleum Ether is recommended.

Pct = Percentage NH = N-Hexane PE = Petroleum Ether

4.2. Performance comparison of the different filters proposed on the ISO 663 with aliquot n°2

In this case, fat spiked with sand was used. According to the preceding results (4.1), Petroleum

Ether was used as solvent.

The influence of different filter types on the impurities recovery rate was assessed (see Figure 6).A

recovery rate close to 100% has therefore to be found. Decrease of this percentage shows an

inability of the filter to recover impurities or another deficiency in the method, for example

practical difficulties, rinsing deficiency…

Figure 6: Boxplot: recovery rate by solvent with the ISO 663 methods

The mean recovery rate of filter crucible was the highest.

The multiple comparison of means showed that there was a significant difference between

cellulose fibre filter and the other filters. On the other hand, there was no significant difference

between glass-fibre filter and filter crucible.

Furthermore beyond the statistical results, practical aspects are also important for the

harmonization of the method. Cellulose fibre filter and glass-fibre filter have to be manipulated

separately and apart from their Buchner funnel. This delicate handling and the non-coaptation

(non-joining together) between the filter and the funnel lead to impurities lost.

4.3. Performance comparison of ISO 663 and AOCS Ca 3a-46 methods with aliquot n°2

In this case, fat spiked with sand was also used. According to the preceding results (4.1 and 4.2),

Petroleum ether and filter crucible were associated with ISO 663.

The influence of both methods on the impurities recovery rate was assessed (Figure 7: AOCS+Glass-

f. and ISO+F. crucible).

The mean recovery rate of AOCS method (see AOCS+Glass-f. in Figure 7) was higher and its

variability was lower. Nevertheless, the multiple comparison of means showed that there was no

significant difference between AOCS method and ISO method. This is explained by the high

variability of the ISO method.

4.4. Performance comparison of ISO 663 and modified AOCS Ca 3a-46 methods with aliquot n°2

In this case, fat spiked with sand was also used. According to the better practical aspects of filter

crucible (4.2), glass-fibre filter was replaced by filter crucible for the AOCS method (named modified

AOCS method). This data was compared with the data of the previous step (4.3).

The influence of both methods on the impurities recovery rate was assessed (Figure 7: AOCS+Glass-

f., AOCS+F.crucible and ISO+F. crucible).

Figure 7: Boxplot: recovery rate by method

The mean recovery rate of modified AOCS method was higher with the lowest variability.

Glass-f. = Glass fibre filter F. crucible = Filter crucible

The multiple comparison of means showed that there was no significant difference between

modified AOCS method and AOCS method and significant difference between modified AOCS

method and ISO 663 method. Nevertheless, modified AOCS method appears like the best

procedure to use in terms of accuracy and practical aspects.

4.5. Performance comparison of ISO 663 and modified AOCS Ca 3a-46 methods with aliquot n°3

In this case, fat spiked with MBM was used. By engraving filter crucible, a weight variation between

each use (on average 1mg) was noticed, probably due to their hydrophilic proprieties or dust. In

order to increase our precision, 20g of aliquot were used for the two methods to limit bias (3% bias

with 20g aliquot against 13% with 5g). Solvent volume was therefore adapted proportionately.

According to the preceding results (4.1, 4.2 and 4.4), glass-fibre filter was replaced by filter crucible

for the AOCS method (named modified AOCS method). Petroleum ether and filter crucible were

associated with ISO 663.

The influence of both methods on the impurities recovery rate was assessed (Figure 8:

AOCS+F.crucible and ISO+F. crucible).

Figure 8: Boxplot: recovery rate by method

The mean recovery rate of modified ISO 663 method was quite higher with a quite lower variability.

F. crucible = Filter crucible

The multiple comparison of means showed nevertheless that there was no significant difference

between ISO 663 method and modified AOCS method.

5. Discussion

The European Commission Health & Consumers Directorate-General requests the EURL-AP opinion

on 2 items:

5.1. Potential differences in performance between the analytical methods which are currently

in use and identification of an appropriate standard for analytical method

This study reveals major difference between the two official methods that can be explained by

different parameters such as the type of filters, the solvent and the aliquot size.

Filter crucible is the more accurate one. As regards practical level, it is also the easiest to handle.

Solvent performance is related to impurities constitution. Kerosene seems to increase the recovery

rate of high density impurities (like sand) whereas Petroleum Ether seems to increase recovery of

lower density impurities (like MBM). Our hypothesis is that it could be correlated with the higher

viscosity of Kerosene.

Tallow is highly heterogeneous. Therefore, composite subsampling made up of several increments

is recommended [9]. Aliquot size must be also large enough to process representative subsamples

and to obtain accurate results. According to the bias resulting from the filter weight variation, an

increase of the aliquot weigh also improves the precision of the method. However, it should be kept

in mind that solvent volume has to be adapted proportionally (10ml of solvent by 1g of aliquot. This

limits the aliquot size. Therefore, the use of 20g of aliquot is recommended.

5.2. EURL-AP’s view on which constituents of tallow should be included in the analysis.

As regards constituents, differences between methods concerns inclusion (ISO 663) or exclusion

(AOCS) of soaps from the analysis through the use of certain solvents.

In the view of the EURL-AP, and within the context of detection of material posing a possible BSE

risk, tallow must be free of protein impurities. Accordingly, standard method must be the more

sensitive as regards as proteins recovery, with inclusion or not of the others impurities.

6. Conclusions

From this study ISO 663 method associated with Petroleum Ether and filter crucible appears to be

the best method within the context of assessment of residual BSE risk in tallow by a best MBM

recovery.

However, the critical point remains the sampling. If sampling is not carried out correctly,

subsequent analytical efforts in the laboratory are futile. It is essential to provide an efficient

method adapted to the laboratory.

7. Acknowledgements

We would like to thank Dr. Viviane Planchon which participated in the statistical analysis for her

help and her guidance in statistical analysis. The authors are also grateful to Marie Collard and

Benoit Scaut for their efficient technical assistance.

References

[ 1 ] Regulation (EC) No 1069/2009 of the European Parliament and of the Council of 21 October

2009 laying down health rules as regards animal by-products and derived products not

intended for human consumption and repealing Regulation (EC) No 1774/2002 (Animal by-

products Regulation). Official Journal of the European Union L 300, 14/11/2009: 1-33.

[ 2 ] Commission Regulation (EU) No 142/2011 of 25 February 2011 implementing Regulation (EC)

No 1069/2009 of the European Parliament and of the Council laying down health rules as

regards animal by-products and derived products not intended for human consumption and

implementing Council Directive 97/78/EC as regards certain samples and items exempt from

veterinary checks at the border under that Directive. Official Journal of the European Union L

54, 26/2/2011: 1-254.

[ 3 ] ISO 663:2007 Animal and vegetable fats and oils – Determination of insoluble impurities

content.

[ 4 ] AOCS Official Method Ca 3a-46 (reapproved 2009) – Insoluble Impurities.

[ 5 ] 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. Official Journal of the European Union L 165,

30/04/2004: 1-141.

[ 6 ] Commission Regulation (EU) No 208/2011 of 2 March 2011 amending Annex VII to Regulation

(EC) No 882/2004 of the European Parliament and of the Council and Commission Regulations

(EC) No 180/2008 and (EC) No 737/2008 as regards lists and names of EU reference

laboratories. Official Journal of the European Union L 58, 3/3/2011: 29-35.

[ 7 ] Opinion of the European Food Safety authority’s Scientific Panel on Biological Hazards on the

‘Assessment of the human and animal BSE risk posed by tallow with respect to residual BSE

risk’ (Question No EFSA-Q-2003-099), adopted on 27-28 April 2005.

[ 8 ] Revised Opinion and Report on the safety of tallow obtained from ruminant slaughter by-

products adopted by the Scientific Steering Committee at its meeting of 28-29 June 2001.

[ 9 ] K.H.Esbensen and P. Paasch-Mortensen. Process Sampling: Theory of Sampling-The Missing

Link in Process Analytical Technologies (PAT).

Page I

Annex 1: Study organisation

Information in red is unspecified in the standard methods.

Table I: Performance comparison of the different solvents proposed on the ISO 663 with aliquot n°1:

Method : Aliquot : Dissolution : Filtration : Flask and Filter Rinsing : Repetition :

ISO

Cellulose fibre filter 3x33ml Hot N-Hexane n=6

200ml N-Hexane, Glass-fibre filter 3x33ml Hot N-Hexane n=6

conical flask, 250ml capacity Filter Crucible 3x33ml Hot N-Hexane n=6

20g

Cellulose fibre filter 3x33ml Hot P.Ether n=6

200ml P.Ether, Glass-fibre filter 3x33ml Hot P.Ether n=6

conical flask, 250ml capacity Filter Crucible 3x33ml Hot P.Ether n=6

Table II: Performance comparison of the different filters proposed on the ISO 663 with aliquot n°2:


ISO

Cellulose fibre filter 3x33ml Hot P.Ether n=12

20g 200ml P.Ether, Glass-fibre filter 3x33ml Hot P.Ether n=12

conical flask, 250ml capacity Filter Crucible 3x33ml Hot P.Ether n=12

Page II

Table III: Performance comparison of ISO 663 and AOCS Ca 3a-46 methods with aliquot n°2:


ISO

20g 200ml P.Ether, Filter Crucible 3x33ml Hot P.Ether n=12

conical flask, 250ml capacity

AO

CS

5g 50ml Kerosene Glass-fibre filter 5x10ml Hot Kerosene n=12

conical flask, 100ml capacity (with Gooch crucible) and

5x10ml P.Ether

Table IV: Performance comparison of ISO 663 and modified AOCS Ca 3a-46 methods with aliquot n°2:


ISO



AO

CS

5g 50ml Kerosene Filter Crucible 5x10ml Hot Kerosene n=12

conical flask, 100ml capacity and

5x10ml P.Ether

Table V: Performance comparison of ISO 663 and modified AOCS Ca 3a-46 methods with aliquot n°3:


ISO



AO

CS

20g

rr

200ml Kerosene Filter Crucible 5x10ml Hot Kerosene n=6

conical flask, 250ml capacity and

5x10ml P.Ether

Page III

Annex 2: European commission request

EUROPEAN COMMISSION HEALTH & CONSUMERS DIRECTORATE-GENERAL Acting Deputy Director-General

Brussels, SANCO/D1/MK/(2010)/D

Subject: Harmonisation of analytical methods for determining insoluble impurities in rendered

animal fat ('tallow')

Dear Sirs,

Tallow is used in animal feed, in the oleochemical industry or as a raw material for the production of biodiesel.

The European Food Safety Authority (EFSA) Biohaz Paneli was invited to assess the validity of the outcome of a

quantitative assessment of the residual BSE risk in tallow and to advise on how to interpret the results of the

calculation in order to make an estimate of the number of potential BSE (cattle) and vCJD (human) cases

expected per year in a population. In general, the exposure levels calculated in the case of tallow are so low that

they can be regarded as minimal. The EFSA opinion supports the Scientific Steering Committeeii opinion that

possible TSE risks associated with tallow will result from protein impurities that may be present in the end-

product.

Under Regulation (EC) No 1774/2002 tallow has to be purified so that the maximum level of remaining total

insoluble impurities does not exceed 0.15 % in weight. However, EU law does not specify the method by which

those insoluble impurities are to be determined. Furthermore, there are different constituents of tallow impurities,

such as mechanical impurities, mineral substances, carbohydrates, nitrogenous substances, alkaline soaps or

oxidised fatty acids, for which it is not established whether or not they are to be included in analytical methods.

According to information received from some Member States and from the rendering sector, in particular the

European Fat Processors and Renderers Association (EFPRA), there are currently two main methods in use,

which, according to the information submitted, would be likely to lead to different results. The first method is ISO

663 with different variations and the second one is method Ca 3a-46 developed by the American Society of Oil

Chemists (AOCS). Some rendering plants use in-house developed methods which are not comparable to the

above. Please see the information from Member States presented in the Annex.

Method ISO 663 has been developed for determining the insoluble impurities content of animal and vegetable fats

and oils. The method includes soaps in the insoluble impurities content.

Method AOCS Ca 3a-46 has been developed for determining sediment in crude fat and oils. This method

excludes soaps from the analysis through the use of certain solvents.

Community Reference Laboratory

for Animal Proteins in Feedingstuffs

Walloon Agricultural Research Centre

Quality of Agricultural Products Department

Chaussée de Namur, 24

B-5030 GEMBLOUX Commission européenne, B-1049 Bruxelles / Europese Commissie, B-1049 Brussel - Belgium. Telephone: (32-2) 299 11 11.

Office: F101-3/56. Telephone: direct line (32-2) 299.58.35. Fax: (32-2) 295.31.44.

http://ec.europa.eu/dgs/health_consumer/foodsafety_en.htm

http://ec.europa.eu/dgs/health_consumer/foodsafety_en.htm

Page IV

More information can be found on the AOCS homepage:

http://www.aocs.org/AOCSBOX/methodsbook/methodssearch/search_methods_view_method.cfm?method=ca3a

_46.pdf.

All in-house methods are based on centrifugation. They are not derived from any of the standard methods.

Method ISO 663 and method AOCS Ca 3a-46 present significant variations in test results. Since they perform

tests on different constituents of insoluble impurities it is possible to find for the same product a negative AOCS

test result and a positive ISO test result.

Furthermore, we would like to refer you to the joint opinion issued by the Federal Institute for Risk Assessment

(BfR) and the Friedrich Loeffler Institute at the request of the German Federal Ministry of Food, Agriculture and

Consumer Protection in response to the discussion paper submitted by EFPRA. In the opinion they present

differences between the ISO 663 and AOCS Ca 3a-46 standards. A translation by the Commission’s translation

service is attached.

At this point we would like to ask you:

1. to assess the potential differences in performance between the analytical methods which are currently in use

and identify an appropriate standard for analytical methods, and

2. to provide us with your view on which constituents of tallow should be included in the analysis.

Should you have any further technical question, my colleagues in Unit D1 are ready to assist.

Their contact details are indicated below.

Yours sincerely,

Bernard Van Goethem

Encl. Information from Member States on methods in use for the determination of insoluble

impurities in tallow

Opinion of the Federal Institute for Risk Assessment (BfR) and the Friedrich Loeffler Institute

Contact persons: Mr T. Gumbel (02-292.15.53)

Mr M. Klemencic (02-298.72.28)

Cc: E Poudelet, K Van Dyck, L. Terzi, A. Brouw, A. Laddomada, A.-E. Füssel, T. Gumbel, Mr F.

Barizzone (EFSA)

i Opinion of the European Food Safety Authority’s Scientific Panel on Biological Hazards on the ‘Assessment of the

human and animal BSE risk posed by tallow with respect to residual BSE risk’ (Question No EFSA-Q-2003-099),

adopted on 27-28 April 2005. ii Revised Opinion and Report on the safety of tallow obtained from ruminant slaughter by-products adopted by the

Scientific Steering Committee at its meeting of 28-29 June 2001.

http://www.aocs.org/AOCSBOX/methodsbook/methodssearch/search_methods_view_method.cfm?method=ca3a_46.pdf

http://www.aocs.org/AOCSBOX/methodsbook/methodssearch/search_methods_view_method.cfm?method=ca3a_46.pdf

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