Effect of milling ratio on sensory properties of cooked rice and on physicochemical properties of milled and cooked rice

Abstract

Quantitative descriptive analysis of cooked rice was performed to investigate the effect of milling ratios (approximate to8.0-14.0%, based on brown rice) on sensory characteristics of cooked rice, in relation to physicochemical characteristics of milled rice and cooked rice. The proximate composition of uncooked rice decreased with increased milling while whiteness increased. The initial pasting temperature of rice flour decreased with increased milling while peak, breakdown, and setback viscosities increased. The instrumental texture profile of cooked rice revealed that hardness and chewiness decreased with increased milling while adhesiveness increased. A trained panel found that color, intactness of grains, puffed corn flavor, raw rice flavor, wet cardboard flavor, hay-like flavor, and bitter taste were lower while glossiness, plumpness, and sweet taste were higher with increased milling. Degree of agglomeration, adhesiveness, cohesiveness of mass, inner moisture, and toothpacking of cooked rice increased while hardness and chewiness decreased with increased milling. Sensory analysis of cooked rice was more discriminating than instrumental texture profile analysis in terms of hardness, adhesiveness, and cohesiveness. There were high negative correlations between descriptive attributes of sweet taste, degree of agglomeration, adhesiveness, cohesiveness of mass, and moisture (r = -0.94 to -0.87), protein (r = -0.96 to -0.83), and fat contents (r = -0.91 to -0.85). Instrumental hardness showed high correlation with sensory hardness (r = 0.80).