Plant-based protein: A multi-nutritional sustainable alternative to animal foods and their structure, functions, and relationship: A review

Plant-based proteins are increasingly recognized as multi-nutritional and sustainable alternatives to animal-derived proteins. Derived from legumes, grains, seeds, and nuts, they provide essential amino acids such as leucine, lysine, methionine, and tryptophan. Soy protein offers 36–40 % protein content with a complete amino acid profile, while pea protein exhibits ~80 % digestibility and high arginine levels (~8.7 g/100 g). Substituting animal proteins with plant-based options may reduce LDL cholesterol by 5–10 % and lower type 2 diabetes risk by 18 %. Environmentally, they contribute up to 90 % fewer greenhouse gas emissions and use 75 % less water than red meat proteins. Structural variations in plant proteins influence their solubility, emulsification, and gelation—critical factors in food formulation. Improved emulsifying activity, such as a 25 % increase with heat-modified lupin proteins, enhances texture and stability. Additionally, plant proteins find applications in pharmaceuticals, cosmetics, and biodegradable packaging. This review highlights their composition, functional and structural properties, industrial applications, and novel processing technologies like enzymatic hydrolysis and fermentation to enhance digestibility and bioavailability, positioning plant proteins as vital agents of human health and sustainability.