Studies on Direct Sowing Culture of Rice in Northern Kyushu. III. Palatability and physicochemical properties of milled rice under direct sowing culture.

Abstract

We aimed to clarify the palatability and physicochemical properties of milled rice under direct sowing Culture in comparison with those under a transplanting culture which had mostly the same ripening period as that of the direct sowing culture. The objective was the selection of a good eating-quality rice cultivar well adapted to the direct sowing culture in Northern Kyushu. Highly palatable cultivars under a transplanting culture showed relatively high palatability for milled rice under the direct sowing culture. The palatability under the direct sowing culture was superior to that under the transplanting culture. Cultivars with highly physicochemical properties under the transplanting culture showed relatively high physicochemical properties for milled rice under the direct sowing culture. The milled rice under the direct sowing culture showed a higher protein content, lower amylose content, and higher maximum viscosity and breakdown values than those under the transplanting culture. Although the directly seeded rice showed a lower yield than the transplanted rice due to the decreased number of panicles per m2, it showed heavier l000grain weight and a higher percentage of ripened grains than those of the transplanted rice. Therefore, it was concluded that the superiority of palatability under the direct sowing culture was caused by the reduction of amylose content and an increase in the maximum viscosity and breakdown values, which was closely related to the extent of grain filling under the direct sowing culture.