Abstract
This study was undertaken to determine the effects of shading during mid- to late-ripening stages on the palatability of cooked rice. The changes in protein content, amylose content, and amylographic characteristics effected by shading were also studied. Rice plants grown in a paddy field were shaded for 10 days by cheesecloth beginning from 15, 20, 25, and 30 days after heading time. About 70% of solar radiation was eliminated by the treatment. All of the shading treatments clearly deteriorated the palatability. The degree of the deterioration was larger in the rice shaded at earlier stages. The shading also increased protein and amylose content and decreased the maximum viscosity and breakdown values in amylographic characteristics. It was estimated that the deterioration of palatability by shading was related to the increase of protein and amylose content and changes in the gelatinization properties of the rice starch.
