Legume byproducts as ingredients for food applications: Preparation, nutrition, bioactivity, and techno-functional properties

The demand for high-quality alternative food proteins has increased over the last few decades due to nutritional and environmental concerns, leading to the growing consumption of legumes such as common bean, chickpea, lentil, lupin, and pea. However, this has also increased the quantity of non-utilized byproducts (such as seed coats, pods, broken seeds, and wastewaters) that could be exploited as sources of ingredients and bioactive compounds in a circular economy. This review focuses on the incorporation of legume byproducts into foods when they are formulated as flours, protein/fiber or solid/liquid fractions, or biological extracts and uses an analytical approach to identify their nutritional, health-promoting, and techno-functional properties. Correlation-based network analysis of nutritional, technological, and sensory characteristics was used to explore the potential of legume byproducts in food products in a systematic manner. Flour is the most widely used legume-based food ingredient and is present at levels of 2%–30% in bakery products, but purified fractions and extracts should be investigated in more detail. Health beverages and vegan dressings with an extended shelf-life are promising applications thanks to the techno-functional features of legume byproducts (e.g., foaming and emulsifying behaviors) and the presence of polyphenols. A deeper exploration of eco-friendly processing techniques (e.g., fermentation and ohmic treatment) is necessary to improve the techno-functional properties of ingredients and the sensory characteristics of foods in a sustainable manner. The processing of legume byproducts combined with improved legume genetic resources could enhance the nutritional, functional, and technological properties of ingredients to ensure that legume-based foods achieve wider industrial and consumer acceptance.