Legume proteins with a focus on seed fractions: Unraveling structural foundations for health-promoting applications

Legume seeds are a rich source of protein and possess high nutritional value, serving as an important source of food and energy. The composition, content, structure, function, and biological activity of proteins vary among various legume species. This study presents a review of innovative advances across ten commonly used leguminous plants: soybean, peanut, chickpea, pea, black soybean, mung bean, astragalus, alfalfa, kidney bean, and cassia seed. The crude protein content in legume seeds generally ranges from 20% to 36%. The review summarizes the functional activities of these protein fractions in terms of antioxidant, cholesterol-lowering, antitumor, antihypertensive, and flavor-enhancing capabilities, as well as their application in product development such as plant-based meat, plant-based beverages, animal feed, cosmetics, and pharmaceuticals. Future work must prioritize standardized extraction, protein-level mechanism, human trials, and cost-effective modification of legume proteins. This review provides theoretical foundations for the further research and development of legume protein resources.