Efeitos do armazenamento em parâmetros de avaliação de qualidade de grãos de quatro genótipos de arroz

Abstract

In rice grains from two hybrids cultivars and two varieties, milled immediately after harvest and after 6 months of storage of grains with husk at the temperature of 20°C, were analyzed levels of 18 amino acids, total protein, amylose, moisture, gelatinization temperature (estimation), plus the parameters of industrial quality, cooking, texture, viscosity and sensory attributes, also preference and acceptance. The results allowed to conclude that: (a) the increase of storage time causes reductions in the amino acid content and changes in amino acid profile, with no significant differences among varieties and hybrids; (b) total protein content from endosperm does not define the degree of loose cooked grains (or of grain stickiness) and it is not associated with the consumer preference for the rice after cooking, (c) elevation in cysteine content causes an increase in loose cooked grain (reduction of stickiness) during storage; (d) parameters of texturometric and rheological evaluations reflect the results from sensory analysis and acceptance of the rice after cooking; and (e) the increase of storage time causes an initial increasing in industrial yield and leads to reductions in whiteness and polishing degree (milling degree), but does not change the transparency of rice .