Valorization of fruit and vegetable processing by-products/wastes

Fruit and vegetable processing by-products and wastes are of great importance due to large quantities of functional compounds. Particularly, apple, grape, citrus, and tomato pomaces, potato peel, olive mill wastewater, olive pomace and olive leaves are the main by-products that occur during production. Besides conventional techniques, ultrasound-assisted extraction, microwave-assisted extraction, pressurized liquid extraction (sub-critical water extraction), supercritical fluid extraction, enzyme-assisted extraction, and fermentation are emerging tools for the recovery of target compounds. In addition to these, on the view of valorization, it is possible to use them in active packaging applications, as a source of bioactive compounds (oil, phenolics, carotenoids), as a functional ingredient and as biofertilizer and biogas sources. This chapter will explain the formation of fruit and vegetable processing by-products/wastes. Moreover, the valorization of functional compounds recovered from the fruit and vegetable by-product and wastes have been identified in detail by emphasizing the type of the by-products and wastes, functional compounds gained from by-products/wastes, extraction conditions and application areas.