Chemical, Physical, and Organoleptic Properties of Twelve Varieties of Rice

摘要

Twelve varieties of polished rice, two grown in Australia and ten elsewhere, have been compared objectively by chemical and physical means and subjectively by tasting panels. Amylose contents ranged between 21.9 and 31.3%, gelatinizing temperatures between 55 and 69C, 'setback' values between -50 and +410 Brabender units, water uptake between 1.9 and 3.2 g/g, and bulk densities between 0.776 and 0.846 g/ml. Eating qualities of these varieties, cooked by two different methods, were assessed by analytical and consumer tasting panels. Statistical analyses of the results showed that there were varietal differences in colour, gloss, and separation of grains; for five other qualities there was little evidence of varietal differences. High amylose contents were associated with better colour and, for the Asian cooking method, were positively correlated with texture. Amylose content was also positively correlated with the viscosity of cooked rice after it had been cooled to 50C; it was similarly correlated with the lowest viscosity during cooking and with gelatinizing temperature. (Author)