Fatty acids, selenium, and vitamin B12 in chub mackerel (Scomber colias) as nourishment considering seasonality and bioaccessibility as factors.

Chub mackerel (Scomber colias) is an underutilised fish abundant in the North Atlantic and a nutritious food with high docosahexaenoic acid (DHA), selenium (Se), and vitamin B12 contents, affected by seasonality. Hence, the bioaccessibility of fatty acid (FA), Se, and vitamin B12 in chub mackerel was studied. Daily consumptions of 51 g, 35 g, and 14 g of March, June, and October chub mackerel, respectively, would ensure EPA + DHA requirements. Vitamin B12 requirements would be met by daily consumptions of 15-18 g of chub mackerel. For Se, larger amounts would be needed, 126-133 g/day. For FA, bioaccessibility often exceeded 80 %. Additionally, Se and vitamin B12 bioaccessibilities were 91-95 % and 77-83 %, respectively. Thus, bioaccessibility-based consumption frequencies for meeting dietary requirements are similar to those above, being the highest consumption frequencies associated to Se requirements, 137-146 g/day. Chub mackerel proved to be an excellent source of bioaccessible essential nutrients.

Collaborative study: Quantification of total folate in food using an efficient single-enzyme extraction combined with LC-MS/MS.

Quantification of the specific folate vitamers to estimate total folate in foods is not standardized. A collaborative study, including eight European laboratories, was conducted in order to determine the repeatability and reproducibility of the method for folate quantification in foods using the plant-origin γ-glutamyl hydrolase as part of the extraction procedure. The seven food samples analyzed represent the food groups; fruits, vegetables, dairy products, legumes, offal, fish, and fortified infant formula. The homogenization step was included, and six folate vitamers were analyzed using LC-MS/MS. Total folate content, expressed as folic acid equivalent, was 17-490 µg/100 g in all samples. Horwitz ratio values were within the acceptable range (0.60-1.94), except for fish. The results for fortified infant formula, a certified reference material (NIST 1869), confirmed the trueness of the method. The collaborative study is part of a standardization project within the Nordic Committee on Food Analysis (NMKL).