The role of scientific and expert advisory committees in food product research and approval.

Scientific and expert advisory committees responsible for food products often have the advantage of being relatively unhindered by rigid regulations and the simultaneous disadvantage of having few guidelines to clarify their role in directing the research and approval process. Committees can thus miss opportunities to function in a proactive advisory capacity, and to assist in predetermining what research and documentation are necessary for regulatory approval of a particular food product. This paper examines the ways scientific and expert committees for nutritional products can contribute to formulation of procedures for effective hypothesis and study design development, preparation of well-structured, complete dossiers for product approval, and transparent interactions with petitioners.

Towards internationally acceptable standards for food additives and contaminants based on the use of risk analysis.

Internationally acceptable norms need to incorporate sound science and consistent risk management principles in an open and transparent manner, as set out in the Agreement on the Application of Sanitary and Phytosanitary Measures (the SPS Agreement). The process of risk analysis provides a procedure to reach these goals. The interaction between risk assessors and risk managers is considered vital to this procedure. This paper reports the outcome of a meeting of risk assessors and risk managers on specific aspects of risk analysis and its application to international standard setting for food additives and contaminants. Case studies on aflatoxins and aspartame were used to identify the key steps of the interaction process which ensure scientific justification for risk management decisions. A series of recommendations were proposed in order to enhance the scientific transparency in these critical phases of the standard setting procedure.

The assessment of food additive usage and consumption: the Commission perspective.

Directive 89/107/EEC on food additives authorized for foodstuffs intended for human consumption includes the requirement that 'all food additives must be kept under continuous observation and must be re-evaluated whenever necessary in the light of changing conditions of use and new scientific information'. During the period June 1994 to March 1995, three specific directives have been adopted, each of them including an obligation for Member States to introduce systems to monitor the usage and consumption of food additives and to report their findings to the Commission within 3 years. They also require the Commission to submit reports to the European Parliament on changes in the additives market, the levels of use and consumption, and to propose amendments to the conditions of use if necessary within 5 years. This paper examines the legal obligations of the Member States and the Commission and proposes practical interpretation of the requirements which would allow realistic and comparable monitoring systems to be set up in the Member States within the limits of their scarce resources. The importance of focusing on public health-related aspects is stressed and consideration is given to the role of the various interested parties and the nature of the Commission's co-ordination responsibility.

Measurement of glucosinolates in rapeseeds.

Several ring tests have been organized by the International Organisation for Standardization (ISO) and the Measurement and Testing Programme (BCR) for improving glucosinolate methods. Finally, HPLC of desulphoglucosinolates is recommended by ISO, the European Committee for Standardization (CEN), and the European Commission (EC) as the official method. X-ray fluorescence has also become particularly common for fast analysis. After checking stability of intact glucosinolates in whole rapeseeds, the BCR has three reference materials (CRM 366, CRM 190, CRM 367) available, certified for their total glucosinolate and sulphur contents. Currently, the Measurement and Testing Programme is supporting a research project concerning the stability of desulphoglucosinolates and intact glucosinolates extracts. At the present time, best results are observed with lyophilized extracts sealed in brown glass ampoules and stored at -18 degrees C.

The development of five animal feed reference materials, certified for their aflatoxin B1 content.

The development of three peanut meal and two compound feed reference materials and the certification of their aflatoxin B1 content is described. The materials were prepared and certified within the Measurements and Testing Programme of the Commission of the European Communities as part of a broad activity to improve accuracy and agreement of results of measurements on food and agriculture. RM 262 (peanut meal) was prepared from uncontaminated peanut products. RM 263 and RM 264 (peanut meals) were prepared from naturally contaminated peanuts which were blended with uncontaminated ones, to achieve the desired aflatoxin B1 mass fractions. RM 375 and RM 376 (compound feeds) were made by blending decontaminated dairy feed together with commercial feed ration and contaminated dairy feed with several feed compounds, respectively. Details are given of the preparation and the investigations to verify homogeneity and stability of the materials. The certification exercise was carried out by 17 laboratories using a variety of extraction and clean-up procedures. Most laboratories used liquid chromatography as the determinative step, although operating under a variety of chromatographic conditions. A few laboratories applied thin layer chromatography with densitometric quantification. Peanut meal RM 262 was certified as containing aflatoxin B1 at a mass fraction of < 3 micrograms/kg, RM 263 at 43.3 +/- 2.1 micrograms/kg and RM 264 at 204 +/- 10 micrograms/kg. Compound feed RM 375 was certified as containing aflatoxin B1 at a mass fraction of < 1 micrograms/kg and RM 376 at 9.2 +/- 0.5 micrograms/kg. The materials can be employed either to establish or confirm a calibration curve, or to check the performance of a method.

Intercomparison of methods for the determination of vitamins in foods. Part 1. Fat-soluble vitamins.

An intercomparison of methods involving 18 European laboratories was organized to assess the state-of-the-art of vitamin determination in foods. Each laboratory received identical samples of dry food reference material (homogeneous powders, milk powder, pork muscle and haricot vert beans), which were recently certified for major dietary components and elements. Each laboratory was requested to perform the analyses by its own methods. Results for fat-soluble vitamins are reported. All participants isolated the fat-soluble vitamins by alkaline saponification. For retinol, only high-performance liquid chromatography (HPLC), reversed- or normal-phase, was applied, with both ultraviolet (UV) and fluorescence detection. Results in milk powder showed a relative standard deviation of reproducibility (RSDReprod) of only 10%. Carotene was determined by HPLC (reversed- and normal-phase) and with open-column chromatography at atmospheric pressure. For beta-carotene results in milk powder agreed very well; the RSDReprod was 14%. The values reported for haricot vert beans showed poor agreement; the RSDReprod was 52%. A major part of this variability was due to differences in methodological principles. The results for alpha-tocopherol in milk powder and haricot vert beans agreed very well, with RSDSReprod of 16 and 15%, respectively. Only HPLC (reversed- and normal-phase) with UV and fluorescence detection was applied.

Intercomparison of methods for the determination of vitamins in foods. Part 2. Water-soluble vitamins.

An intercomparison of methods involving 18 European laboratories was organized to assess the state-of-the-art of vitamin determination in foods. Each laboratory received identical samples of dry food reference material (homogeneous powders, milk powder, pork muscle and haricot vert beans), which have recently been certified for major dietary components and elements. Each laboratory was requested to perform the analyses by its own routine methods. The results for water-soluble vitamins are reported. The reproducibility for the determination of vitamin B1 in milk powder, pork muscle and haricot vert beans with high-performance liquid chromatography (HPLC), fluorimetric and microbiological methods was good, with the relative standard deviation of reproducibility (RSDReprod) ranging from 11 to 18%. Differences between laboratories for the determination of the vitamin B2 content of milk powder, pork muscle and haricot vert beans determined using HPLC and microbiological methods were very high, with RSDReprod ranging from 28 to 74%. The extraction and hydrolysis procedures were probably the most important sources of variation. For vitamin B6 various HPLC and microbiological methods were used. The variation in the results for vitamin B6 was high, except in milk powder. The RSDReprod ranged from 18 to 51%. A major part of this variability was due to differences in the extraction and hydrolysis procedures and problems with the identification of the vitamin B6 vitamers by HPLC. Variation in the results for niacin obtained with the microbiological methods in milk powder, pork muscle and haricot vert beans, was small; RSDReprod = 9-15%.(ABSTRACT TRUNCATED AT 250 WORDS)

Deoxynivalenol in wheat and maize flour reference materials. 2. Preparation and certification.

The preparation of four cereal reference materials (two wheat and two maize) and the certification of their 4-deoxynivalenol (DON) contents is described. The materials were prepared and certified within the BCR programme of the Commission of the European Community as part of a broad activity to improve accuracy and agreement of measurements of importance in food and agriculture. Reference material RM 379 was prepared from naturally contaminated wheat four blended with 'blank' material to achieve the desired DON content. The reference material RM 378 was prepared from naturally contaminated maize identified as containing approximately the desired DON content. Details are given of the milling, blending and packaging procedure, and the checks to ensure homogeneity and stability of the materials. The reference materials RM 396 and 377 were similarly prepared from the blank wheat and maize samples respectively. The certification exercise was carried out by five laboratories (with a further two to three laboratories providing supporting data) using a variety of extraction and clean-up procedures with either high performance liquid chromatography (HPLC) or gas chromatography (GC) as the determinative stages. Wheat RM 379 was certified as containing DON at a level of 673 +/- 21 micrograms/kg and wheat RM 396 as containing less than 50 micrograms/kg. Maize RM 378 was certified as containing DON at 425 +/- 38 micrograms/kg and maize RM 377 as containing less than 50 micrograms/kg. The materials are intended for the verification of methods used to determine DON in cereal samples.

Deoxynivalenol in wheat and maize flour reference materials. 1. An intercomparison of methods.

To provide a basis for the certification of wheat and maize flour reference materials containing deoxynivalenol, a series of three preliminary intercomparisons of methods was carried out between 1985 and 1988. The first intercomparison, involving 10 laboratories was designed to examine the determinative step and used a solution of deoxynivalenol in ethyl acetate and a spiked wheat extract solution. The second intercomparison involving 13 laboratories established minimum extraction times for naturally contaminated samples, demonstrated the absence of matrix effects in purified extracts and showed that there was no evidence of differences in the use of any of three different end determinations. The third intercomparison involving 15 laboratories used naturally contaminated cereals and acted as a preliminary to the final certification exercise. Over a period of four years there was a steady improvement in the range of results submitted by participants thought to be due to the application of improved analytical methods, increased expertise in the analysis and through experience gained through the intercomparisons.

The preparation, validation and certification of the aflatoxin content of two peanut butter reference materials.

The preparation of two peanut butter reference materials and the certification of their aflatoxins B1, B2, G1, G2 and total aflatoxin contents is described. The materials were prepared and certified within the BCR Programme of the Commission of the European Community as part of a broad activity to improve accuracy and agreement of measurements of importance in food and agriculture (Wagstaffe and Belliardo 1990). Reference material RM 385 was prepared from naturally contaminated peanuts, roasted and ground into a paste and then blended with uncontaminated peanut butter to achieve the desired aflatoxin concentrations. Details are given of the blending and canning procedure, and the checks to ensure homogeneity and stability of the material. Reference material RM 401 was similarly prepared but from an uncontaminated peanut butter. The certification exercise was carried out by nine laboratories using a variety of extraction and clean-up procedures, but all using high performance liquid chromatography (HPLC) as the determinative stage although operating under a variety of chromatographic conditions. RM 385 was certified as containing aflatoxins B1, B2, G1 and G2 at levels of 7.0 +/- 0.8 micrograms/kg, 1.1 +/- 0.2 micrograms/kg, 1.7 +/- 0.3 micrograms/kg and 0.3 +/- 0.2 micrograms/kg respectively (total aflatoxin content of 10.1 +/- 1.5 micrograms/kg) and RM 401 as containing aflatoxin B1, B2 and G2 at less than 0.2 micrograms/kg and aflatoxin G1 at less than 0.3 micrograms/kg (total aflatoxin content less than 0.9 micrograms/kg). The materials are intended for the verification of methods used to determine aflatoxins in nuts and nut products.

Aflatoxin B1 in compound-feed reference materials: an intercomparison of methods.

The BCR has undertaken a project to prepare compound-feed reference materials to provide a basis for analytical quality control for this assay. The first phase of the project, an intercomparison of methods for aflatoxin B1 in compounded feedstuffs at a level of ca 15 micrograms/kg is now described. The study involved 24 European laboratories who analysed two pairs of compounded feedstuffs. Each pair of feeds consisted of a contaminated and an almost uncontaminated sample (a near-blank) of otherwise identical composition. The feed pairs differed essentially only in their citrus-pulp and barley contents. The participants used a variety of methods of analysis, including chloroform, methanol-water and acetonitrile-water for extraction, TLC, reversed phase disposable cartridges and immunoaffinity columns for extract clean-up and TLC, HPLC and ELISA in the determinative step. Several performance characteristics were checked and the aflatoxin B1 contents were determined. Recoveries were found to range from approximately 70 to 110%. Coefficients of variation calculated from all the results obtained with the two pairs of contaminated samples were 16 and 19%. The study showed that, when properly applied, a number of methods employing variations in extraction, clean-up and end-method gave results which were in close agreement. It is concluded that there exists a sound basis for the establishment of reference values for the aflatoxin B1 content of compound feed reference materials which have been prepared in this project.

Validation of a quantitative procedure for the extraction of sterols from edible oils using radiolabelled compounds.

The work described in this paper is integrated in an analytical programme organised by the Community Bureau of Reference with the aim of developing reference materials certified for sterol content. Preliminary inter-comparison of methods showed that the level of agreement of the results was insufficient for certification purposes. Errors could occur in the different steps before the final determination by gas-liquid chromatography. It was, therefore, decided to validate a quantitative procedure for the isolation of sterols. A well defined saponification-extraction method was tested using labelled sterols ([3H]cholesterol and [3H]cholesteryl oleate) and radiochemical measurements. The study has shown that total cholesterol recovery reached 100.5 +/- 1.4%, that cholesteryl ester was saponified quantitatively and that there were no appreciable amounts of degradation products. The procedure has been used as the basis for the certification of three reference materials and it has been shown that the saponification and extraction procedure leads to the quantitative recovery of sterols regardless of the nature of the fatty material tested.

Aflatoxin B1 in peanut meal reference materials: intercomparisons of methods.

The Community Bureau of Reference (BCR) is preparing a series of animal feed reference materials to provide a basis for analytical quality assurance for aflatoxin B1 analysis, a problem of particular importance in view of Community legislation. Before reference values can be assigned to the reference materials the major errors in the underlying measurements must be identified and reduced. This paper presents the results of two intercomparison exercises involving some 20 European laboratories who applied a wide variety of analytical methods. It is shown that the major source of error and discrepancy is connected with incomplete extraction and/or losses during clean-up and that, provided correction for recovery/background interference is made, many methods can achieve acceptable accuracy. Sources of error and their control are discussed, and essential details of the methods used are presented. It is concluded that analytical QA is more important than the use of standardized methods when a high degree of accuracy and comparability are required.

Development of milk powder reference materials certified for aflatoxin M1 content (Part II): Certification of milk powder RM 283.

The development of a full cream milk powder reference material, certified for its aflatoxin M1 content (target concentration: 0.1 microgram/kg), is described. The material (RM 283) was prepared and certified within the Reference Material Programme of the Community Bureau of Reference, along with other members of a series of milk powder reference materials. Homogeneity, evaluated by determining the aflatoxin M1 content of 30 units, was found to be acceptable (coefficient of variation of analysis results: 9.1%); stability has been demonstrated in a long-term study. The certification exercise involved 7 laboratories. Calibration, control of recoveries, blank values, and independence of the replicate measurements were emphasized. All sets of results of the certification exercise were accepted for statistical evaluation. A certified value for the aflatoxin M1 content: 0.09(+0.04)(-0.02) micrograms/kg was derived. The certification of RM 283 completes the series of 4 milk powder reference materials having certified aflatoxin M1 contents.

Aflatoxin M1 in whole milk-powder reference materials.

The development of three full cream milk powder reference materials, certified for their aflatoxin M1 content, is briefly described. The materials were prepared and certified within the Reference Material Programme of the Community Bureau of Reference. The three reference materials RM's 282, 284 and 285 contain aflatoxin M1 at concentrations of: less than 0.05 microgram/kg, 0.31 +/- 0.06 microgram/kg, and 0.76 +/- 0.05 microgram/kg.

Development of milk powder reference materials certified for aflatoxin M1 content (Part I).

The development of 3 full-cream milk powder reference materials, certified for their aflatoxin M1 content, is described. The materials were prepared and certified within the Reference Material Programme of the Community Bureau of Reference (BCR). The 3 reference materials, RMs 282, 284, and 285, contain aflatoxin M1 at concentrations of less than 0.05, 0.31 +/- 0.06, and 0.76 +/- 0.05 micrograms/kg, respectively. The preparation, testing for homogeneity, stability of the reference materials, and the certification exercise, which was preceded by 2 intercomparisons of methods, are discussed. Particular emphasis was placed on the independence of the measurements in the certification exercise and the control of errors associated with extraction efficiency and the aflatoxin M1 calibrant. Finally, some guidance is given on avoiding the principal sources of errors in the determination of aflatoxin M1. Details concerning the supply of the reference materials will be provided by BCR on request.