Waxy wheat extrusion: Impacts of twin-screw extrusion on hard red waxy wheat flour

Background and objectives Two varieties of hard red spring waxy wheat were extruded with varying barrel temperatures, screw speeds, feed moistures, and screw profiles to determine their extrusion processing characteristics. A nonwaxy control wheat was also extruded to examine differences that occur in the extrusion of waxy wheat. Findings It was found that radial expansion ratios of waxy wheat were approximately 4.5 with specific conditions and were similar to expansion ratios obtained from nonwaxy wheat. However, specific mechanical energy requirements for nonwaxy wheat far exceeded both of the waxy wheat varieties to produce this expansion. In doing so, the nonwaxy wheat also produced extrusion pressures that were nearly double that of pressures generated from waxy wheat. Conclusions The results demonstrated that hard red waxy wheat may offer a low-energy extrusion alternative to conventional wheat flour extrusion. Significance and novelty This study highlights the differences in the processing energy consumption between hard red waxy wheat and nonwaxy wheat. The results demonstrate that waxy wheat may offer lower operational costs for extrusion and presents excellent potential in the development of new consumer food products.