Effect of different extrusion treatments and particle size distribution on the physico-chemical properties of rice flour

Abstract

Rice flour is an interesting alternative for developing gluten free products, but its features do not meet the process requirements. The objective of this study was to modify the functional properties of rice flour by combining extrusion and size fractionation. Different extrusion conditions were applied to vary the severity of the treatment on the flour constituents. Extrusion and mechanical fractionation of the rice flours modified their behavior affecting hydration, thermal and pasting features, besides their susceptibility to enzymatic hydrolysis. Thermal properties (temperature and enthalpy) increased with the intensity of the extrusion and that effect was intensified with the greatest particle size of the flours. Fine flours with stronger extrusion showed the highest susceptibility to enzymatic hydrolysis and extrusion process increased that effect. Overall the combination of both physical treatment maybe an attractive alternative for obtaining clean label rice flours with modified features.