Effects of blend and extrusion processing on the quality of extrudates made from milk protein and maize

Abstract

The quality of extrudates is determined by consumers acceptance based upon the main criteria like colour and appearance along with some other parameters. We studied some of the characteristics of extrudates, colour value, Water Absorption Index (WAI), Water Solubility Index (WSI), expansion ratio of extrudates from different blends of milk protein and maize flour as affected by the composition of blends during extrusion processing. Maize flour was extruded with two different milk protein sources i.e Whey protein concentrate-70 (WPC-70) and rennet casein at different proportion (90:10, 80:20), feed moisture content 12%, feed rpm 340 rpm and extrusion temperature 100°C. Increasing the milk protein content resulted in higher L*, a*, b* value, lower expansion ratio, WAI, WSI in the final extruded product