Abstract: Northern erect panicle type rice is one of the important super-rice strains. However, the palatability of this kind of rice is generally unsatisfactory. In this study, 70 samples of erect panicle type and non-erect panicle type rice were chosen to identify the variability in the palatability of erect panicle type rice and to analyze the possible causes. Textural analyzer and rapid viscosity analysis (RVA) were used to detect the viscoelasticity of cooked rice and rice starch, respectively; meanwhile, the differences in rice protein and apparent amylose contents and amylopectin fine structures (Fa, Fb1 + 2 and Fb3) were analyzed. The results showed that: 1) all samples were classified by the Ward method into three categories, and erect panicle type rice could not classified into one of these categories; moreover, the categories with high proportions of erect panicle type rice possessed low adhesiveness and stringiness, high hardness and chewiness, small breakdown and high setback value, which revealed poor palatability, and endosperm composition presented high apparent amylose content (AAC), protein content (PC) and Fb3 content as well as low Fa/Fb3 ratio; 2) generally, viscoelasticity had a close correlation with AAC, Fb3 content and Fa/Fb3 ratio, but the correlation among these categories was different. Compared with RVA characteristics, texture properties had greater correlation with endosperm composition; 3) the major texture parameters were closely related with the RVA results. All the above results indicate that there may be no direct correlation between panicle type and viscoelasticity. Some erect panicle type rice cultivars have poor palatability such as high hardness and low viscosity which may be related to endosperm starch composition. Compared with RVA characteristics, texture analyzer is a more direct and simpler method to evaluate rice palatability.

Key words: japonica rice, texture properties, rapid viscosity analyzer characteristics, endosperm composition, panicle type