Sensory evaluation of cooked rice in relation to water-to-rice ratio and physicochemical properties

Abstract

The effects of cooking water-to-rice (W/R) ratio on the sensory characteristics of cooked rice eating quality of 14 varieties of Thai rice were investigated in relation to their physicochemicai properties. Milled rice samples were cooked with five W/R ratios ranging from 1.3 to 2.5 on a weight basis and presented to 12 trained panelists for sensory evaluation. A three-way analysis of variance and a principal component analysis identified the intensity of sensory hardness as the main characteristic of cooked rice. It decreased with increasing W/R ratio whereas sensory stickiness decreased. The overall acceptability based on appearance, texture and flavor attributes reached peak levels corresponding to optimum W/R ratios for different rice varieties, and was highly correlated with sensory hardness and stickiness. Partial least squares regression models of optimum W/R ratio and peak overall acceptability gave coefficients of determination of 0.991 and 0.980, respectively, thus indicating that the optimum W/R ratio and the acceptability ratings of cooked rice could be reliably predicted from the physicochemical properties such as the apparent amylose content, protein content, gel consistency, alkali spreading value and grain elongation ratio of milled rice. © 2007, Blackwell Publishing.