Cottonseed proteins: A promising and undervalued non-grain protein source for aquafeed

The projected expansion of aquaculture production cannot rely solely on fishmeal (FM) due to its unsustainability and increasing price. Therefore, novel FM alternatives with high nutritional value, excellent digestibility, great palatability, low toxicity, and abundance without competing with human food sources is a crucial strategy for promoting sustainable aquaculture. Cottonseed proteins have been identified as valuable non-grain protein sources in aquaculture, with a production history tracing back to the 1950s. In recent years, the advancements in processing equipment and technologies have successfully optimized the production of cottonseed proteins that meet desired attributes of FM alternatives. Cottonseed protein concentrate is a prime example, obtained through low-temperature solvent extraction, de-gossypolization, and moderate raffinose isolation to enhance its nutritional value and palatability. This review provides a comprehensive overview of the research advancements concerning cottonseed proteins in aquafeed, including a detailed examination of their production processes, physicochemical properties, feed processing characteristics, nutritional values, and a meta-analysis on the growth performance of aquatic animals when cottonseed proteins are used as alternatives to fish meal in feed.