Physical Properties of Refabricated Rice as Affected by Extrusion: A Response Surface Analysis

摘要

The aim of this study was to optimize the extrusion conditions for production of refabricated rice using a response surface modeling approach. The effects of feed moisture content, screw speed, and barrel temperature on the physical properties of rice grains refabricated using a corotating twin-screw extruder were investigated. Rice flour (variety PR-116) obtained from broken grains (smaller than one-eighth of a whole grain) was used in the study. Screw speeds at five levels between 49 and 150 rpm, barrel temperatures between 59 and 110 degrees C, and feed moisture contents between 31 and 45% were tested. All of the physical properties of the refabricated rice grains that were evaluated (thousand kernel weight, length/breadth ratio, bulk density, and breaking strength) were significantly (P < 0.01) affected by these three process variables. Response surface regression models were established to correlate the physical properties of refabricated rice grains to the process variables. Understanding the effects of process variables on the physical properties and optimization of extrusion conditions was deemed useful for the development of high-quality refabricated rice.