Novel extrusion-based plant protein separation technology and its effect on the techno-functional properties of faba bean protein

• A novel extrusion-based protein separation technology is introduced. • Faba bean flour was fractionated to protein-rich and starch-rich extrudates. • The protein fraction had high protein content (71-77%) and protein yield (60-85%). • The protein fraction had similar functionality as textured vegetable proteins. • The starch-rich fraction had cold-water swelling capacity. This study introduces a new, efficient processing technology for separating protein from plant materials, responding to the growing demand for sustainable, cost-effective, and healthy protein alternatives. The separation process is based on a novel dry extrusion which allows for the simultaneous production of both protein-enriched and starch-enriched fractions. The produced protein-enriched granules can be further processed into powder-type ingredient by grinding, but the granules could also be used without grinding similar to conventional textured vegetable protein (TVP). The raw material used in this study was faba bean, a promising yet underutilized source of plant protein. By studying different extrusion conditions in laboratory scale, a protein-rich fraction with high protein content (71-77% of dry matter) and protein yield (60-85%) was obtained. The protein fractions had bulk density of 453-523 g/l, water and oil absorption capacity of 2.3-2.5 g/g and 0.94-1.01 g/g, respectively, and hardness of 753-845 g, which align with the properties of commercial TVPs. The starch-rich fraction had cold-water swelling capacity, offering potential in diverse food applications. This new protein separation technology opens new opportunities in the development of sustainable and cost-efficient high-quality plant protein ingredients and alternatives for animal protein-based foods.