High demands for plant-based proteins have led food technologists to search for new and alternative sources. This review presents and discusses recent developments in the recovery of proteins from plant origin by-products. The innovative protein extraction techniques have advantages over conventional methods as they are cheap, eco-friendly, high efficiency as well as produce versatile final products. Different recovery techniques provide variable yields and features whereas the resulting protein isolates/hydrolysates are dependent upon the type of material and process conditions. Future studies are required to exploit potential plant-origin agro-industrial by-products, and to investigate the efficiency of recovery.

Sour (tart) cherry is an industrial fruit where a considerable amount of by-products remain after processing. Sour cherry by-products consist of pomace (skin and flesh) and seeds (pit, stone) which remain after the fruit juice and IQF processes. Sour cherry pomace is characterized with a high content of phenolic compounds and the seed constitutes a high oil yield with beneficial effects on human health because of their antioxidant, antimicrobial, and anti-inflammatory properties. There has been a great interest in sour cherry by-products due to the increasing production rate of sour cherry worldwide and the increasing efforts on seeking bioactive compounds from natural sources as functional food. Thus, there have been a number of studies regarding the sour cherry pomace and sour cherry seed, especially in the last five years. The present review summarizes the chemical, biological, functional, and technological properties of the sour cherry pomace and sour cherry seed with their current and potential applications.