Relation of Nitrogen Content and Mg/K Ratio of Brown Rice to Stickiness of Cooked Rice

Abstract

The relation of nitrogen content and Mg/K chemical equivalent ratio to varietal difference in stickiness of cooked rice of nonwaxy japonica rice in war]TLer area were evaluated. 30 varieties ih 1984 and 35 varieties in 1986 were grown on the Institute's farm. The stickiness of varieties was evaluated by sensory test. The scale employed for the test was 1 1 grades from 5 (much more sticky than Nipponbare) to - 5 (not very well sticky com-pared with Nipponbare), and the stickiness ranged from - 1.04 to 1.00 in 1984 and - 0.79 to 1.00 in 1986, respectively. The samples of 1984 ranged in composition from 1.20 to 1.54% for nitrogen and 1.17 to 1.73 for Mg/K ratio. The samples of 1986 ranged in com-position from 1.02 to 1.51% for nitrogen and 1.23 to 1.73 for Mg/K ratio. Stickiness cor-related negatively with nitrogen content, but the correlation coefficient in 1984 was not siguificant. Since the coefficient of variation of nitrogen content in 1984 was small compared with that in 1986, no significance of the correlation coefficient in 1 984 may be due mainly to its narrow varietal difference of nitrogen content. On the other hand, the correlation be-tween stickiness and Mg/K ratio was positively significant in each year (Table 2).