Molecular aspects of nutritionally improved sorghum and buckwheat, two sustainable crops

Drought and global warming are the most prominent abiotic stresses limiting crop production and productivity. Buckwheat is a short-season crop that grows well in low-fertility or acidic soils, while sorghum does best in semi-arid and arid tropics. Both crops are a major staple for roughly a billion people, mostly in developing countries. Buckwheat and sorghum are gluten-free grains, since their proteins do not contain coeliac-toxic sequences. In spite of their high protein and fiber content, the use of these crops in human nutrition may be limited by the presence of several anti-nutritional factors that limit nutrient bioavailability. Processes based on the use of eso- or endo- enzymes represent a suitable method for improving the bioavailability of both micro- and macro- nutrients, and are a sustainable way to obtain high quality foods from sustainable species. The biochemical changes ensuing from the action of endogenous seed proteases after short-time sprouting (48-72h) of buckwheat and sorghum grains included a less compact protein structure and a high release of peptides. The overall features of proteins in the sprouted grains made them more suitable for formation of the inter-protein network fundamental for appropriate texturing of specific foods. Sprouting-associated enzymes also decreased the levels of anti-nutritional factors such as enzymatic inhibitors, phytates and chelating compounds, increasing the bioavailability of metals, fatty acids, and free polyphenols. All together these result suggest that flour from germinated buckwheat and sorghum may be regarded as a nutritionally and technologically improved food ingredient. This research is part of the project “MIND FoodS HUB (Milano Innovation District Food System Hub) cofunded by POR FESR 2014-2020_BANDO Call HUB Regione Lombardia.