Valorization of Persimmon and Blueberry Byproducts to Obtain Functional Powders: In Vitro Digestion and Fermentation by Gut Microbiota

Globalization of fruit and vegetable markets generates overproduction, surpluses, and potentially valuable residues. The valorization of these byproducts constitutes a challenge, to ensure sustainability and reintroduce them into the food chain. This work focuses on blueberry and persimmon residues, rich in polyphenols and carotenoids, to obtain powders with high added value to be used as ingredients in food formulation. These powders have been characterized, and the changes in the bioactive compounds in in vitro gastrointestinal digestion have been evaluated. The results indicated that the type of residue, the drying process, as well as the content and type of fiber determine the release of antioxidants during digestion. In vitro colonic fermentations were also performed, and it was observed that the characteristics of digested powders had an effect on the composition of the growing microbial community. Thus, carotenoids and anthocyanins maintain an interplay with microbiota that could be beneficial for human health.