External Scientific Report - Updated food composition database for nutrient intake

This report is the final report of the EFSA contract CFT/EFSA/DCM/2011/03. The aim of the project was to provide EFSA with an updated food composition database covering approximately 1750 foods in combination with additional FoodEx2 facet descriptors included in the EFSA FoodEx2 classification system, and to expand the dataset to include harmonised information on the most common composite recipes of European countries and harmonised information on food supplements. Proposals for models of nutrient composition, composite dishes and food supplement databases were developed as well as guidelines for mapping food data in national datasets to EFSA FoodEx2 codes and facet descriptors. A model for data transfer, compatible with the EuroFIR technical annex and CEN Food Data Standard, and the EFSA data structure was developed and tested. Fourteen national food database compiler organisations supplied initial food lists mapped to the EFSA food list. Information on commonly consumed composite dishes was provided by compilers from thirteen countries and information on food supplements was provided by compilers from eight countries. Datasets compatible with EFSA‟s data structure were produced based on the models. In addition, guidelines developed and limitations of the data produced are discussed.EFS

Folate bioavailibility: UK Food Standards Agency workshop report

The UK Food Standards Agency convened a group of expert scientists to review current research investigating folate bioavailability. The workshop aimed to overview current research and establish priorities for future research. Discrepancies were observed in the evidence base for folate bioavailability, especially with regard to the relative bioavailability of natural folates compared with folic acid. A substantial body of evidence shows folic acid to have superior bioavailability relative to food folates; however, the exact relative bioavailability still needs to be determined, and in particular with regard to mixed diets. The bioavailability of folate in a mixed diet is probably not a weighted average of that in the various foods consumed; thus the workshop considered that assessment of folate bioavailability of whole diets should be a high priority for future research

Improvements in the determination of vitamins in foods: Method intercomparison studies and preparation of certified reference materials (CRMs)

Accurate methods for the determination of vitamins in food are required for nutritional labelling, and for the production of food composition data for nutritional research on relationships between diet and health. The Standards, Measurement and Testing Programme of the European Commission is supporting a collaborative project involving 48 laboratories to improve their measurement in food. The research programme involves the use of method intercomparison studies to identify and control systematic errors, optimization of sample extraction and clean-up procedures, and the preparation of suitable food reference materials (RMs). Results are presented for the determination of vitamin D3 by HPLC and folates by microbiological assay in various foods demonstrating improved agreement between laboratories and possible reasons for improvements. In addition, examples of the food RMs produced and their potential use are described

Certification of B-group vitamins (b1, b2, b6, and b12) in four food reference materials

In 1989, the Community Bureau of Reference started a research program to improve the quality of vitamin analysis in food. To achieve this task, vitamin methodology was evaluated and tested by interlaboratory studies and the preparation of certified reference materials, which will be used for quality control of vitamin measurements. The main improvements in methodology were achieved by testing and standardizing the extraction condition and enzymatic hydrolysis procedures. Results for each individual material are derived from five replicate determinations using at least two independent methods: Liquid chromatography (HPLC) and microbiological assay for vitamins B1, B2, and B6; and radioprotein binding and microbiological assays for vitamin B12. The certificate of analysis for four reference materials gives mass fraction values for water-soluble vitamins. These certified values were based on the acceptable statistical agreement of results from collaborating laboratories. Certified values with uncertainties (mg/kg dry matter) for each CRM are as follows: 4.63 (0.20) and 4.10 (0.51) for vitamins B1 and B6, respectively, in CRM 121 (wholemeal flour); 6.51 (0.24), 14.54 (0.3), 6.66 (0.43), and 0.034 (0.003) for vitamins B1, B2, B6, and B12, respectively, in CRM 421 (milk powder); 3.07 (0.17) and 4.80 (0.40) for vitamins B1 and B6, respectively, in CRM 485 (lyophilized mixed vegetables), and 8.58 (0.55), 106.8 (2.8), 19.3 (1.5), and 1.12 (0.044) for vitamins B1, B2, B6, and B12, respectively, in CRM 487 (lyophilized pig liver)

Third EU MAT intercomparison on methods for the determination of vitamins B-1, B-2 and B-6 in food

An intercomparison study on the determination of vitamin B-1, B-2 and B-6 was performed as part of the EU MAT project involving 16 laboratories. Each laboratory was requested to analyse three different food samples (lyophilized pig's liver, mixed vegetables and wholemeal flour, respectively) using their 'in-house' method as well as an 'optimal extraction protocol' and using a common batch of takadiastase enzyme. High-performance liquid chromatography (both normal-phase and reversed-phase HPLC), microbiological assay and chemical methods were used. For vitamins B-1 and B-2 the agreement between laboratories (using their 'in-house' methods) was generally good (vitamin B-1: CV(w) < 5%, CV(b) = 16-28%; vitamin B-2: CV(w) < 8%; CV(b) = 12-40%, respectively, where CV(w) is the within-laboratory coefficient of variation and CV(b) is the between-laboratory coefficient of variation) with no apparent differences between the 'in-house' and 'optimal' extraction protocols. For vitamin B-1 microbiological results tended to be higher (e.g. ca 20-50%) than HPLC results. Some further improvement could result from optimalization (i.e. lowering) of the sample-enzyme ratio. Enzyme efficiency needs to be checked with each new batch of enzyme. For vitamin B-6 results were much more at variance (CV(w) = 6-13%, CV(b) = 36-63%), especially with the pig's liver. Some discrepancy was found between laboratories using dilute mineralic acid for extraction without enzyme treatment and those using trichloroacetic acid (TCA) and/or included takadiastase treatment. It is concluded that for vitamin B-6 further standardization and method improvement is needed in order to obtain acceptable variation between laboratories. In particular, B-6 vitamer interconversion during extraction and peak interference needs further study

[6S]5-methyltetrahydrofolate or folic acid supplementation and absorption and initial elimination of folate in young and middle-aged adults

Objectives: To assess the effects of supplementation with the diastereoisomer of 5-methyltetrahydrofolate ([6S]5-methylTHF), as an alternative supplement for folic acid, on folate absorption and elimination, in two age groups. Design: A randomized, double-blind intervention study. Subjects: A total of 12 young (<30 y) and 12 middle-aged (≥50 y) healthy volunteers were recruited. Methods: Volunteers were randomized to receive daily supplementation with 400 μg folic acid or equimolar amounts of [6S]5-methylTHF during 5 weeks. Before and after supplementation, absorption and initial elimination were calculated following oral [2H2]folic acid test doses using isotope kinetics in plasma. Results: Folic acid absorption was lower in the middle-aged as compared to the young adults, both before (P=0.03) and after (P=0.05) supplementation. In the young adults, absorption decreased by 22% after [6S]5-methylTHF and increased by 21% after folic acid (P=0.02). In the other age group, no such changes were found. The folate rate constant of elimination increased after folic acid supplementation in the young (+50%; P=0.05) but not in the middle-aged (+18%; P=0.5) adults. Conclusions: Young adults show increased folate turnover after folic acid supplementation relative to the effect of [6S]5-methylTHF supplementation. Similar differences are not observed in middle-aged adults, in whom folic acid absorption was found to be lower as compared to the young adults

Research goals for folate and related B vitamin in Europe

In the past decade, the understanding of folate bioavailability, metabolism and related health issues has increased, but several problems remain, including the difficulty of delivering the available knowledge to the populations at risk. Owing to the low compliance of taking folic acid supplements, for example, among women of child-bearing age who could lower the risk of having a baby with a neural tube defect, food-based strategies aimed at increasing the intake of folate and other B-group vitamins should be a priority for future research. These should include the development of a combined strategy of supplemental folate ( possibly with vitamin B-12), biofortification using engineered plant-derived foods and micro-organisms and food fortification for increasing folate intakes in the general population. Currently, the most effective population-based strategy to reduce NTDs remains folic acid fortification. However, the possible adverse effect of high intakes of folic acid on neurologic functioning among elderly persons with vitamin B12 deficiency needs urgent investigation. The results of ongoing randomized controlled studies aimed at reducing the prevalence of hyperhomocysteinemia and related morbidity must be available before food-based total population approaches for treatment of hyperhomocysteinemia can be recommended. Further research is required on quantitative assessment of folate intake and bioavailability, along with a more thorough understanding of physiological, biochemical and genetic processes involved in folate absorption and metabolism