关键词: 优质粳稻, 南方粳稻, 北方粳稻, 品质特征

Abstract:

【Objective】The differences of physical and chemical characteristics related to appearance and taste of some high-quality japonica rice varieties in China were studied in order to provide some theoretical basis for improvement of high-quality japonica rice varieties.【Method】39 japonica rice varieties participating in the second national high-quality rice variety taste quality evaluation activities were used as materials to study the differences in appearance and cooking taste quality of different japonica rice varieties, and to analyze the relationship between various physical and chemical indexes of rice and taste quality. 15 japonica rice varieties that won the second national high-quality rice variety taste quality evaluation gold medal were divided into two major sources of south and north according to regions, and the differences in appearance and taste related physical and chemical indexes of japonica rice from different regions were compared and studied.【Result】(1) The 39 japonica rice varieties participating in the second national high-quality rice variety taste quality evaluation activities had great differences in grain type, chalkiness rate and chalkiness degree. In terms of cooking taste, the taste value measured by the rice taste meter and the sensory score of experts were 44.00-82.00 and 52.20-91.86, respectively. Amylose content of rice, setback, consistence in RVA spectrum, stickiness and balance in texture characteristics of rice were significantly negatively correlated with taste value of rice, with correlation coefficients of -0.39, -0.60, -0.57, -0.37 and -0.56, respectively. However, the peak viscosity and breakdown in RVA spectrum were significantly positively correlated with the taste value of cooked rice, with correlation coefficients of 0.32 and 0.36, respectively. (2) Compared with northern high-quality japonica rice, chalkiness rate and chalkiness degree of southern high-quality japonica rice increased by 178.78% and 139.11%, respectively; amylose content decreased by 28.25%, protein content increased by 7.37%; setback and consistence in RVA spectra of rice flour decreased by 12.00% and 21.19%, respectively. The absolute values of stickiness and balance in texture characteristics of cooked rice increased by 16.15% and 15.00%, respectively; There was no significant difference between the taste value measured by the rice taste meter and the expert sensory score between the high-quality japonica rice from the south and the north.【Conclusion】The appearance and cooking taste quality of japonica rice varieties participating in the second national high-quality rice variety taste quality evaluation activities were significantly different. The appearance of northern japonica rice was crystal clear, chalkiness degree was 0.50%-3.50%, amylose content of rice was high, protein content was low, and taste was 56.00-74.00. However, the appearance of southern japonica rice was relatively turbid with chalkiness degree of 1.86%-11.21%. Although the protein content was high in rice, the amylose content was low, the rice cooked was soft and sticky, and the taste value was 54.00-82.00.

Key words: high-quality japonica rice, southern japonica rice, northern japonica rice, quality characteristics