Triacylglycerol profiling by using chromatographic techniquesTriacylglycerols (TGs) make up the major part of naturally occurring fats and oils. The composition and fine structure of TGs determine to a large extent the functionality of fats and oils as food ingredients and the physiological effects of fats and oils as component of the human diet. Analysis of intact TGs is usually performed by chromatographic methods. In this article the application of gas-liquid chromatography, highperformance chromatography in normal and reversed phase mode, thin-layer chromatography and supercritical fluid chromatography for the qualitative and quantitative determination of TGs is reviewed. Emphasis is put on those factors that are decisive for obtaining reliable quantitative data. Furthermore, techniques for the stereospecific analysis of the fatty acid distribution along the glycerol backbone of TGs are presented briefly.

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This document provides supplemental guidance on specifications for the development and implementation of studies to validate the performance characteristics of quantitative ELISA methods for the determination of food allergens. It is intended as a companion document to other existing publications on method validation. The guidance is divided into two sections: information to be provided by the method developer on various characteristics of the method, and implementation of a multilaboratory validation study. Certain criteria included in the guidance are allergen-specific. Two food allergens, egg and milk, are used to demonstrate the criteria guidance. These recommendations will be the basis of the harmonized validation protocol for any food allergen ELISA method, whether proprietary or nonproprietary, that will be submitted to AOAC and/or regulatory authorities or other bodies for status recognition. Regulatory authorities may have their own particular requirements for data packages in addition to the guidance in this document. Future work planned for the implementation and validation of this guidance will include guidance specific to other priority allergens.

Allergen detection and quantification is an essential part of allergen management as practiced by food manufacturers. Recently, protein MS methods (in particular, multiple reaction monitoring experiments) have begun to be adopted by the allergen detection community to provide an alternative technique to ELISA and PCR methods. MS analysis of proteins in foods provides additional challenges to the analyst, both in terms of experimental design and methodology: (1) choice of analyte, including multiplexing to simultaneously detect several biologically relevant molecules able to trigger allergic reactions; (2) choice of processing stable peptide markers for different target analytes that should be placed in publicly available databases; (3) markers allowing quantification (e.g., through standard addition or isotopically labeled peptide standards); (4) optimization of protease digestion protocols to ensure reproducible and robust method development; and (5) effective validation of methods and harmonization of results through the use of naturally incurred reference materials spanning several types of food matrix.

This review describes the European Union and the US regulations applicable to food colours. Despite the different regulatory frameworks, the overall approach is similar, based on wellestablished risk-assessment procedures and risk-management measures. However, differences impacting free movement of goods can be found in the details and implementation of regulations. Using additives approved only in the US or in the EU implies that producers aiming to export need to adjust their product composition to the export market. Failure to comply may give rise to claims of adulteration, misbranding or non-compliance and rejection at the border or recall from the market. A careful comparison of the level of protection provided by the two sets of regulations, the criteria of good manufacturing practice (GMP) inspections and the certification requirements could be key to aligning the rules and to negotiating mutual recognition agreements. This review provides an extensive overview of the similarities and differences in regulating food colours in the EU and the US. ARTICLE HISTORY

The concept of theoretical response factors is not directly applicable to methyl esters of short-chain fatty acids (FA), since their carbon deficiency is larger than expected from theory. Substituting the methyl group by an ethyl, propyl, or butyl group improved the flame-ionization efficiency of fatty acid esters gradually, up to the point where the empirical response factors of the butyl esters were identical within experimental error to the theoretical values. Butyl esters of FA have a uniform flame-ionization detection (FID) response irrespective of the number of carbon atoms contained in the FA. They exhibit a carbon deficiency of 1.0, i.e. the carbonyl carbon atom does not respond, as expected from theory. Compared to methyl esters, which have a carbon deficiency of 1.4-1.5 for shortchain FA, use of butyl esters has the advantage that a precalculation of the FID response enables the analyst to judge whether the analytical system employed works properly and the data produced are accurate and reliable. Both acid (BF 3 or H 2 SO 4 )-and alkali (butoxide)-catalyzed butyl ester preparation were equally effective, giving the analyst a choice of methods so that different analytical needs can be addressed efficiently. Computing response factors and comparing the theoretically expected values with those obtained experimentally gives the experimenter an indication whether the analytical system employed for FA profiling (transesterification plus the subsequent gasliquid chromatographic separation and quantitation by FID) works properly. This setup is particularly useful for an accurate analysis of the FA profile of milk fat.Paper no. J8919 in JAOCS 76, 263-266 (February 1999). KEY WORDS:Fatty acid esters, flame-ionization detector, gas-liquid chromatography, response factors.Fatty acid (FA) profiling of edible fats and oils by gas-liquid chromatography (GLC) is an analytical procedure widely applied in the oils and fats industry. One of the major problems associated with this technique is discrimination of substances differing to a larger extent in molecular weight during sample introduction (1). Cold on-column injection (OCI) eliminates discrimination in the injector (2). Factors contributing to the fact that an FA profile expressed as area-% is mostly not equal to weight-% are: (i) discrimination effects occurring during sample introduction, (ii) irreversible adsorption of analytes in the chromatographic system, (iii) thermal instability of analytes, and (iv) uneven detector response towards different compounds (3-5). Bannon, Craske and co-workers (3,4,6-8) investigated thoroughly the accuracy of fatty acid methyl ester (FAME) analyses and concluded that by using an optimized analytical setup only theoretical response factors (TRF), calculated according to Ackman and Sipos (5), are necessary to convert FAME area-% to weight-%. The concept proved to be valid for fats with FA containing four or more carbon atoms. Milk fat (MF) is the only natural fat containing substantial amounts of short-chain FA. This unique featur...

The current essential therapy of celiac disease is a strict adherence to a gluten-free diet. Besides food products that are naturally gluten-free, “very low gluten” and “glutenfree” bakery products have become available. The availability of immunochemical and other analytical methods to determine gluten markers in foods is of utmost importance to ensure the well being of gluten-sensitive individuals. The aim of this review was to evaluate if currently available methodologies are suitable to meet the requirements of food labeling standards for individual gluten source declaration, in order to achieve policy objectives. Codex Alimentarius and European Union (EU) legislation and gluten detection methodologies applicable at present have been summarized and compared. In 2009, the European Commission issued Regulation No. 41/2009 concerning the composition and labeling of foodstuffs suitable for people intolerant to gluten. This review constitutes a basis to investigate the possibility to develop a proteomic-based method for the specifc detection of gluten-containing cereals in food products, especially at or around the limits specifed in EU legislation.