A Comprehensive Review of Cowpea Proteins: Chemistry, Extraction, Techno-Functionality, Modification, and Food Applications

Cowpea (Vigna unguiculata) is a versatile legume crop recognized for its nutritional profile and potential as an alternative protein source in the food industry. The protein content of cowpea is about 20%–32%. The growing demand for sustainable and cost-effective plant proteins has increased research into cowpea protein (CP) chemistry, extraction methods, functional properties, and applications. CPs are mainly comprised of albumins, globulins, and glutelins, with globulins being the dominant fraction. Extraction methods, including wet techniques such as alkaline, acid, water, and salt extractions, as well as dry fractionation, significantly influence the yield, purity, and functional properties of CPs. The functional attributes can be further enhanced through enzymatic, physical, and chemical modifications. Despite notable progress, challenges such as poor functionality, resource-intensive extraction methods, and beany off-flavor limit their broader applications. Recent advancements in protein modifications and eco-friendly extraction technologies have opened new possibilities for CPs in novel applications, such as meat analogs, edible films, and encapsulation. However, the effects of individual modification methods and their combinations on functional properties and underlying mechanisms remain underexplored. This review provides a comprehensive analysis of the chemistry, processing methods, functionality, modifications, and food applications of CPs. It also highlights future trends and aims to guide further research while advancing processing technologies for CPs.