Extraction, encapsulation, and bioaccessibility of polyphenols from fruit and vegetable by-products and their health effects: a decade overview.

The fruits and vegetable processing industry produces a huge amount of by-products that are rich in bioactive compounds. Therefore, the recovery of these biologically active compounds from industry by-products has received significant attention. Polyphenols are recognized for their therapeutic potential, including anti-carcinogenic, anti-inflammatory, and antioxidant properties. However, they are highly sensitive and easily degraded, and also have lower bioaccessibility due to their instability in gastrointestinal conditions. To increase stability and improve the bioaccessibility of polyphenols, encapsulation is considered an effective approach to enhance stability and facilitate proper release during digestion. The present review highlights different efficient techniques used for the extraction of bioactive compounds from fruit and vegetable by-products (FVBPs), including conventional (soxhlet, maceration) and green extraction (supercritical fluid, pulsed electric field, pressurized liquid extraction) techniques. These extraction techniques utilize different solvents (methanol, ethanol, acetone, diethyl ether, propanol) to extract bioactive compounds. Additionally, the review focused on polyphenols' encapsulation techniques, delivery systems, and encapsulating agents to maintain their stability, enhance their bioaccessibility, and ensure targeted delivery in the gastrointestinal tract, as well as the health-promoting effects of encapsulated polyphenols extracted from FVBPs.