Abstract
The global food system is under pressure to shift toward protein sources that can sustain a growing population without depleting natural resources. This review discusses plant-derived proteins in the context of human nutrition, focusing on their composition, quality, biological effects, and potential for dietary use. Protein content, amino acid profiles, and digestibility differ widely across legumes, cereals, pseudocereals, oilseeds, and novel sources. Soy and potato proteins show the highest quality among plant sources under the DIAAS scoring system, approaching values typical of animal proteins. Cereal proteins are generally lower in quality, largely because they lack sufficient lysine and are less digestible. Processing methods such as heating, fermentation, enzymatic treatment, and non-thermal techniques can reduce antinutritional compounds while preserving amino acid availability. Beyond providing essential nutrients, plant proteins appear to influence appetite regulation, support muscle maintenance, improve gut health through microbial metabolites, and offer protection against several chronic conditions, including cardiovascular disease, type 2 diabetes, and kidney dysfunction. These benefits, however, are not easily realized. Barriers related to cultivation, manufacturing, sensory properties, affordability, and regulation continue to limit their broader adoption. With appropriate processing and careful blending of complementary sources, plant-derived proteins can serve as a practical and sustainable component of human diets.