Lack of data on folate in convenience foods: Should ready-to-eat products be considered relevant for folate intake? The European challenge

Folate Content and Yolk Color of Hen Eggs from Different Farming Systems

This study aimed to compare folate contents in hen eggs from four different farming systems, namely organic, free range, barn, and cage one. Folate retention during egg boiling was studied as well. The contents of individual folate vitamers were determined using the high-performance liquid chromatography method (HPLC), following trienzyme treatment. Folate content in eggs differed significantly (p < 0.05) due to the rearing system, with the highest mean content determined in the eggs from organic farming (113.8 µg/100 g). According to this study, one egg (60 g) may provide 40-86 µg of folates, which corresponds to 10-22% of the recommended daily intake for adults, 400 µg according to the Nutrition Standards for the Polish Population. The predominant folate form found in egg was 5-methyltetrahydrofolate, which showed considerably greater stability under boiling compared to 10-formylfolic acid present in a lower amount. In most eggs tested, the losses in total folate content did not exceed 15%. The color of yolk of the most folate-abundant organic eggs, had the highest value of lightness (L*) and the lowest value of redness (a*). This, however, does not correspond to consumer preferences of intense golden yolk color.

Supplementation with fruit and okara soybean by-products and amaranth flour increases the folate production by starter and probiotic cultures

The ability of two starter cultures (Streptococcus (S.) thermophilus ST-M6 and St. thermophilus TA-40) and eleven probiotic cultures (St. thermophilus TH-4, Lactobacillus (Lb.) acidophilus LA-5, Lb. fermentum PCC, Lb. reuteri RC-14, Lb. paracasei subsp. paracasei, Lb. casei 431, Lb. paracasei subsp. paracasei F19, Lb. rhamnosus GR-1, and Lb. rhamnosus LGG, Bifidobacterium (B.) animalis subsp. lactis BB-12, B. longum subsp. longum BB-46, and B. longum subsp. infantis BB-02) to produce folate in a modified MRS broth (mMRS) supplemented with different fruit (passion fruit, acerola, orange, and mango) and okara soybean by-products and amaranth flour was investigated. Initially, the folate content of each vegetable substrate was determined: passion fruit by-product showed the lowest folate content (8±2ng/mL) and okara the highest (457±22ng/mL). When the orange by-product and amaranth flour were added to mMRS, all strains were able to increase folate production after 24h of fermentation. B. longum subsp infantis BB-02 produced the highest concentrations (1223±116ng/mL) in amaranth flour. Okara was the substrate that had the lowest impact on the folate production by all strains evaluated. Lb. acidophilus LA-5 (297±36ng/mL) and B. animalis subsp. lactis BB-12 (237±23ng/mL) were also able to produce folate after growth in mMRS containing acerola and orange by-products, respectively. The results of this study demonstrate that folate production is not only strain-dependent but also influenced by the addition of different substrates in the growth media.

Folates: Chemistry, analysis, occurrence, biofortification and bioavailability

Folates (Vitamin B₉) include both naturally occurring folates and synthetic folic acid used in fortified foods and dietary supplements. Folate deficiency causes severe abnormalities in one-carbon metabolism can result chronic diseases and developmental disorders, including neural tube defects. Mammalian cells cannot synthesize folates de novo; therefore, diet and dietary supplements are the only way to attain daily folate requirements. In the last decade, significant advancements have been made to enhance the folate content of rice, tomato, common bean and lettuce by using genetic engineering approaches. Strategies have been developed to improve the stability of folate pool in plants. Folate deglutamylation through food processing and thermal treatment has the potential to enhance the bioavailability of folate. This review highlights the recent developments in biosynthesis, composition, bioavailability, enhanced production by elicitation and metabolic engineering, and methods of analysis of folate in food. Additionally, future perspectives in this context are identified. Detailed knowledge of folate biosynthesis, degradation and salvage are the prime requirements to efficiently engineer the plants for the enhancement of overall folate content. Similarly, consumption of a folate-rich diet with enhanced bioavailability is the best way to maintain optimum folate levels in the body.

Folates in Fruits and Vegetables: Contents, Processing, and Stability

Folates play a key role in human one-carbon metabolism and are provided by food. It is well established that folates are beneficial in the prevention of neural tube defects and cardiovascular and neurodegenerative diseases. Fruits and vegetables, and especially green vegetables, are the main sources of folates. In parallel, fruits and vegetables, with high contents of folates, are mostly consumed after processing, such as, canning, freezing, or home-cooking, which involve folate losses during their preparation. Hence, it is important to know the percentage of folate losses during processing and, moreover, the mechanisms underlying those losses. The current knowledge on folate losses from fruit and vegetables are presented in this review. They depend on the nature of the respective fruit or vegetable and the respective treatment. For example, steaming involves almost no folate losses in contrast to boiling. Two main mechanisms are involved in folate losses: (i) leaching into the surrounding liquid and (ii) oxidation during heat treatment, the latter of which depending on the nature of the vitamer considered. In this respect, a vitamer stability decreases in the order starting from folic acid followed by 5-HCO-H₄ folate, 5-CH₃ -H₄ folate, and, finally, H₄ folate. Further studies are required, especially on the diffusion of the vitamers in real foods and on the determination of folate degradation products.

Contribution of folic acid-fortified foods to fertile women's folate Recommended Nutrient Intake through breakfast simulation models

OBJECTIVE

To assess the potential contribution of foods fortified with folic acid (FA) to target population intakes when included as part of a healthy breakfast.

DESIGN

Breakfast models aligned with the Spanish Dietary Guidelines were studied using the recommended, average and 95th percentile of serving sizes consumed by women of childbearing age. Food composition data were obtained from a database including FA analytical data from sixty-eight products and the Spanish food composition tables. Different scenarios were assessed with the inclusion of one, two or three FA-fortified products and with two different fortification levels: ≤ 33 µg/serving (L1) and ≥ 70 µg/serving (L4). FA contents provided by the different models for each scenario were compared with the Recommended Nutrient Intake (RNI) for folate and the Upper Level (UL) of intake for FA.

SETTING

Madrid Region, Spain.

SUBJECTS

Women aged 16-49 years were considered.

RESULTS

Overall, simulation of ten breakfast models and three scenarios of product inclusion accounted for 20-25% of total daily energy recommendations for women. Unfortified breakfast models provided on average 4-23% of the folate RNI. Inclusion of one L4 FA-fortified food contributed 20-60% of the RNI. Fortified yoghurt and milk had the highest FA contents per serving. Scenarios with two or three fortified products delivered 40-80% of the RNI. None of the evaluated models exceeded the FA UL.

CONCLUSIONS

At existing levels of FA fortification, inclusion of fortified products as part of a regular breakfast meal could positively impact the nutritional quality of women's diet without involving a risk of excessive FA exposure.

Diet, cognition, and Alzheimer's disease: food for thought

INTRODUCTION

The prevention of Alzheimer's disease (AD) has become a real challenge due to its rising prevalence and the lack of an effective cure. Diet and nutrients have gained significant interest as potentially modifiable protective factors.

PURPOSE

The aim of this review is to provide an updated summary of evidence related to the effect of diet and nutritional factors on the risk of AD and cognitive aging, and discuss the potential mechanisms and confounding factors involved.

METHODS

A search was conducted in Medline and Web of Knowledge for epidemiological and clinical studies in the international literature from January 2000 to February 2013 using combinations of the following keywords: "Alzheimer's disease", "mild cognitive impairment", "cognitive function", "dietary factors", "omega-3", "antioxidants", "B vitamins", "dietary patterns", and "Mediterranean diet".

RESULTS AND CONCLUSION

Data from observational studies point to a protective role for certain nutrients, such as omega-3 fatty acids, antioxidants or B vitamins, and dietary patterns (Mediterranean diet). However, data from randomized controlled trials do not show a consistent effect. Whether confounding factors such as age, disease stage, other dietary components, cooking processes, and other methodological issues explain the divergent results remains to be established. Moreover, if certain nutrients protect against dementia, it is as yet unknown whether they may have a general effect on brain vascular health or directly interfere with the etiopathogenesis of AD.