Value-Added Processing of Food Legumes Using Extrusion Technology: A Review

Extrusion processing of legumes has gained increased commercial significance in recent years. Food legumes or pulses are a rich source of protein, total dietary fiber, starch, minerals, selected vitamins, and other bioactive compounds with antioxidant activity. The relatively higher protein and lower carbohydrate contents than cereal grains make legumes a healthy choice for developing new food products. While legumes are a staple in many developing countries, their consumption remains to be very low in most of the developed countries. Developing legume-based ready-to-use ingredients and ready-to-eat products can potentially increase legume consumption, especially in developed countries. In addition to traditional legume processing methods, extrusion cooking offers a cost-effective option to manufacture legume-based products and ingredients. In recent years, increased concerns by consumers about environmental sustainability and food security have resulted in promoting plant-based proteins as meat substitutes and meat analogs, which are primarily produced by extrusion or wet/dry extraction. In this regard, extrusion is more sustainable and environment-friendly processing technology due to its process efficiency and minimal effluents. Legumes processed by extrusion cooking have wide applications in a variety of food products, for example, flour mixes and doughs, snack items, baked foods, meat alternatives, meat extenders, gluten-free products, and nutraceuticals. Furthermore, extrusion process improves the digestibility and functional properties, and lowers or eliminates the antinutrients found in most legumes. This comprehensive review article discusses extrusion processing technology/systems, legumes extrusion, and nutritional quality, functional properties, food safety, and consumer acceptance of extruded legume products.