Lentil Flours as Sustainable Source of Proteins for the Food Industry

Abstract

The growing transition toward a plant-based diet, coupled with the need for sustainable dietary protein sources, has driven interest in legumes. Lentils, due to their accessibility, sustainability, and high nutritional value, emerge as a promising option as protein flour for food development. This study aims to evaluate different functional and nutritional properties of lentil flours: brown lentil flour (BF), dehulled red Turkish lentil flour (DTF), and dehulled brown lentil flour (DBF). The lentil type and its processing (dehulling) influenced the chemical composition of the products. DTF exhibited the highest protein, whereas BF had the highest ash and total dietary fiber, and DBF showed the highest starch content. Protein digestibility was significantly higher in dehulled flours (78%) than in BF (68%). Regarding techno-functional properties, DBF excelled in gel textural characteristics, exhibiting greater hardness, resilience, cohesiveness, and elasticity—key attributes for industrial applications requiring specific textures and high stability. Concerning bioactive properties, ABTS+ radical scavenging and reducing power were higher for BF-aqueous extracts (34.91% and 7.77 mmol Trolox/gAG, respectively). Meanwhile, β-carotene bleaching inhibition was greater in the aqueous extracts of BF and DBF (~34.5%). These findings position DTF as a high-quality protein source due to its nutritional composition and high digestibility. DBF, on the other hand, is a promising option for developing foods where textural properties are critical for consumer acceptance, while BF stands out for its high bioactive compound content. Lentil flours are established as sustainable protein sources and versatile ingredients for the food industry, contributing to the promotion of healthier foods.