Determination of folate content in ready-to-eat food products

Abstract

In the last years, the consumption of ready-to-eat foods has become an increasing part of the current Spanish diet. Accordingly, the nutritional composition of these food categories should be investigated in order to estimate its contribution to vitamin and nutrient intakes, in particular its folate content. The broad lack of folate data in food composition tables and databases justifies this approach. The aim of this work was to screen the current availability and to supply new folate data in ready-to-eat commercial products in the Spanish market. Seventeen ready-to-eat foods, including mainly vegetable ingredients, were analysed for total folate content using a validated method that relies on Lactobacillus casei ssp. rhamnosus chloramphenicol-resistant folate dependent growth. The accuracy of the analytical procedure was checked using a certified reference material and by a recovery test. Mean TF content ranged from 13.6 to 103.8 μg/100 g in different food matrices on a fresh weight basis. Higher TF quantity was found for vegetable hamburguers, recipes including chickpeas, peas or artichockes. Selected precooked products were also analysed after a soft heat treatment as recommended by the manufacter before its consumption. No significant differences were found in the folate content after processing. The coefficient of variation for the duplicates of the same product was less than 15%. Folate content in ready-to-eat products indicates the potential to considerably increase folate intake by choosing folate-rich foods. There have been no previous reports on folate data in chilled ready-to-eat meals. The present data will assist dietary studies to estimate and evaluate the adequacy of population folate intakes.