Bio-functional properties of extruded corn gluten meal after simulated gastrointestinal digestion.

The objective of the research was to employ extrusion to increase the yield of simulated gastrointestinal digestion of protein corn gluten meal (CG). A single-screw extruder and a full factorial design with two center points were used. The optimal extrusion parameters were 40 % sample moisture, 140 °C and 54 rpm, resulting in a gastrointestinal digestion yield of 37.3 %. The influence of the optimized extrusion condition on other bio-functional properties of CG after simulated gastrointestinal digestion was assessed. Unextruded undigested CG (control), unextruded digested CG, extruded undigested CG, and extruded digested CG were compared in terms of bio-functional properties. Extruded digested CG showed higher nitrogen content, degree of hydrolysis, digestibility, ABTS•+ scavenging activity, reducing capacity, and angiotensin-converting enzyme inhibitory activity than the other samples. In addition to facilitating the gastrointestinal digestion of CG proteins, extrusion also increases their bioactive potential, adding value to this residue for use in human food.