Evaluation of the content and the potential bioavailability of minerals from gluten-free products.

INTRODUCTION Gluten-free products usually contain low amounts of protein and minerals. However, the information about their nutritional quality is limited. The objective of this study was to determine the content and release of minerals from selected gluten-free products. MATERIAL AND METHODS The content and release of Ca, Mg, Fe, Zn and Cu from selected gluten-free products was determined. The samples were subjected to enzymatic digestion under in vitro conditions. The content of minerals in samples before and after enzymatic digestion was determined by the fl ame atomic absorption spectrometry. RESULTS The content of minerals varied considerably among the types of foods. The amount of calcium in gluten-free products ranged (mg/100 g d.w.) from 3 in corn porridge to 45 in peas puff, magnesium: from 13 in peas puff to 33 in corn porridge, iron: from 1.1 in bread to 2.6 in pasta, zinc: from 0.8 in biscuits to 6.3 peas puff and copper: from 0.07 in bread to 0.4 in pasta. Among analysed products the significant higher release of calcium (~68%) and zinc (~62%) was found in corn porridge. The highest potential bioavailability for magnesium (~54%) in peas puff, for iron (~58%) in biscuits and for copper (~63%) in bread was observed. The relative low bioavailability of minerals was found in pasta (from 7% for Ca to 27% for Fe). CONCLUSIONS The content and amount of released minerals from gluten-free products are relatively low. The release of minerals from gluten-free products depends on the element and composition of the analysed product.