Kinetic study of extrusion cooking of corn-rice flour blend fortified with nutraceutical concentrates with respect to various physical parameters

摘要

Purpose - The purpose of this paper is to investigate the effect of residence time distribution in extrudersalong with the incorporation of nutraceuticals on the final quality of the products with respect to severalpivotal responses.Design/methodology/approach - Corn-rice flour blend fortified with isolated nutraceutical concentratesat two (low and high) levels was extruded at barrel temperature (110°C), screw speed (260 rpm) and feedmoisture (17 percent). Extrudates were collected at an interval of 24 s followed by analysis for radialexpansion (RE), bulk density (BD), water absorption index (WAI), sensory score (SS), textural hardness,colorimetric values (L*, a* and b*) and color difference (E).Findings - The entire data were fitted to zero- and first-order kinetic models. There was a gradual decreasein RE, SS and L* value, whereas an increase in BD, textural hardness and a* value of extrudates fortified withthe three nutraceutical concentrates was observed with the successive time interval of 24 s along with a morepronounced effect on color difference (E) observed during the last stages of extrusion time. The zero-orderkinetic model was well fitted for BD and a* value, whereas the first-order kinetic model showed better resultsfor RE, WAI, SS, textural hardness, L* value, a* value and b* value of fortified extrudates.Originality/value - Nutraceuticals like β-glucans, lignans and y oryzanol exhibit numerous health-beneficialeffects. This study analyzes the kinetics of changes in various responses of extrudates fortified with thesenutraceutical concentrates during extrusion.