Solid-State Fermentation for the Recovery of Phenolic Compounds from Agro-Wastes

Polyphenolic compounds are a group of secondary metabolites in plants; these molecules are widely distributed in fruits, vegetables, and herbs and can be found in the vacuoles of plant cells. The current trend in these compounds is their extraction to study their applications in several areas, such as the food, cosmetic, and pharmacology industry. This review article presents a critical analysis of polyphenol extraction using solid-state fermentation. The parameters of extraction, such as the substrate, temperature, pH, inoculum of the microorganism, moisture, and water activity, are discussed in detail. This biotechnological extraction method affects the concentration and recovery of polyphenolic compounds. Some polyphenolic sources that are rising for their biological properties belong to agro-industrial wastes, such as peels, seeds, and the pulp of some fruits. Solid-state fermentation is an innovative and environmentally friendly tool that can contribute to generating value-added agrifood from agro-industrial wastes.