Microbial valorization of fruit processing waste: opportunities, challenges, and strategies

Fruit processing waste (FPW) is a major resource of carbohydrates that can be converted into valuable products through microbial fermentation. Thus, microbial processing of FPW represents a promising strategy to reduce the agroindustrial waste and gain the economic profit. Numerous studies have focused on technological breakthroughs associated with microbial fermentation process in FPW biorefineries. However, previously reported processes involving the preparation of biomass hydrolysate have been poorly described despite their substantial contributions to fermentation performance. This critical review discusses the opportunities and challenges associated with FPW-based microbial processing, with an emphasis on technical considerations on hydrolysate preparation specific to fruit biomass. Also, with selected product examples of biofuel, organic acid, single-cell protein, and enzyme, this study demonstrates the state-of-the-art fermentation strategies.