Valorization of Fruit and Vegetable By-Products for Protein Extraction and their Functional Applications in Food and Non-Food Sectors

The fruit and vegetable processing sector generates substantial quantities of underutilized by-products, creating both economic losses and environmental challenges. Addressing these issues requires innovative strategies for converting these byproducts into valuable resources. This review explores the potential for recovering proteins from by-products of different fruits and vegetables and highlights their uses in the food and non-food sectors. Various extraction techniques, including conventional methods and emerging green extraction techniques, such as pressurized liquid extraction, enzyme-assisted extraction, and pulsed electric extraction, have been evaluated for their effectiveness in isolating proteins while preserving their functional characteristics. The extracted proteins provide substantial nutritional and functional benefits, making them ideal for use in the development of functional foods, fortification, and nutraceuticals. Non-food applications of the extracted proteins, including animal feed, edible films, bioplastics, and biopolymers, are also discussed. To maximize the potential of proteins, future studies should focus on improving sustainable extraction techniques, as well as their regulatory, economic, and safety aspects, and expand the functional applications of these proteins. The purpose of this review is to contribute to healthier and more sustainable food systems by emphasizing the recovery of proteins from fruit and vegetable processing waste streams.