Abstract
We investigated some palatability properties of Ibaraki rice cv. Koshihikari, specifically examining the correlation of palatability with grain weight and thickness. We investigated the rice from 20 paddy fields in which common management methods were applied using chemical fertilizers. Raising seedlings, transplantation, fertilization, watering, and harvesting were done using various farmers’ methods. After harvest, yield and yield components, brown rice grain size, and palatability were investigated. Yield was 330—617 kg/10a. Brown rice thickness was 1.93—2.02 mm (mean 1.99 mm). The mean 1000-grain brown rice weight (20.3—22.7 g) was 21.5 g which was the same as that in the ‘Promotion Campaign to Purchase Ibaraki Rice’ campaign objective. No relationship was observed between brown rice thickness and 1000-grain weight. The mean percentage of milled-rice protein contents was 6.4% : less than the campaign objective. The mean milled rice amylose content (18.3—19.8%) was 18.9%. Percentages of protein, amylose content, and the palatability index of milled rice were not significantly correlated with the 1000-grain weight or brown rice thickness. These results indicate that in thick brown rice with a high 1000-grain weight, protein and amylose contents of milled rice are not related with the brown rice size. Moreover, Koshihikari rice of Ibaraki prefecture of 2005 used in this study seemed to have a high palatability.
