Circular reuse of bio-resources: the role of Pleurotus spp. in the development of functional foods

The basdiomycetes fungi belonging to the genus Pleurotus could make an important contribution to sustainable functional food design because they possess an elevated protein content with a valuable essential amino acid scoring pattern, a unique dietary fibre profile, mainly comprised of branched beta-glucan, high levels of some vitamins of the B group, vitamin D, Fe, Zn, Cu, Se and some bioactive mycochemicals, while the Na and fat contents are low. Moreover, Pleurotus spp. can grow efficiently on various clean by-products of food processing, such as wheat straw, wheat stalk and spent beer grain, thus representing a sustainable food source. This review illustrates the compositional variability of Pleurotus spp. grown on various by-products, in order to clarify its potential ability to address the needs of populations with endemic nutritional deficiencies as well as those populations at risk or affected by some chronic diseases. The perspectives for Pleurotus applications in functional foods decisively depend on consumers' acceptability. Hence, the sensory properties of Pleurotus spp. are also clarified herein. Lastly, the three main strategies of functional food development using Pleurotus spp. are summarized, namely its use as a fortifying agent, high-cost protein replacer and prebiotic ingredient.