The potential of fermentation on nutritional and technological improvement of cereal and legume flours: A review

Nowadays there is an increasing demand for vegetable protein sources as an alternative to that of animal origin, not only for its greater environmental sustainability but also for its relationship with lower risk of suffering cardiovascular diseases. Legumes, cereals and seeds are seen as a good proteinaceous source providing as well dietetic fiber and phytochemicals with antioxidant properties. However, their digestibility and bioavailability are limited by the presence of anti-nutritional factors (ANFs) but susceptible of being improved by soaking, cooking or fermentation. The objective of this work is to review the solid-state and submerged fermentation effect on nutritional and functional properties of legumes, cereals and seeds. The microorganisms involved (bacteria, fungus and yeasts) are able to produce enzymes that degrade ANFs giving rise to more digestible flours with a more interesting nutritional, sensorial and technological profile. Solid-state fermentation is more commonly used for its higher efficiency, accepting agro-industrial residues as substrates and its lower volume of effluents. Fermented legumes had their technological properties enhanced while an increment in antioxidant properties was characteristic of cereals. The present review highlights fermentation of cereals and legumes mainly as a key process that at industrial scale could generate new products with enhanced nutritional and technological properties.