Comparison of Brewing Characteristics of Different Types of Rice and Prediction of Evaluation Indexes

In order to explore the relationship between the appearance quality and processing quality of different types of rice and the starch characteristics of special rice for brewing, screen rapid identification indexes and establish a special variety evaluation system, 17 indica rice varieties, 10 japonica rice varieties, and 11 indica/japonica types were used as experimental materials. A total of 12 indexes of amylose, amylopectin and total starch content, processing quality and appearance quality of rice were detected and analyzed. Taking amylose content ≥ 24 % as the threshold, the correlation analysis and principal component analysis were used for comprehensive evaluation. The results showed that there was a significant positive correlation between amylose content and amy-lopectin, total starch content, chalky grain rate and chalkiness degree, and a significant negative correlation with head rice rate; through principal component analysis, six identification indexes of wine indica rice were further screened, including amylopectin, total starch content, chalky grain rate, chalkiness degree, head rice rate and transparency. The thresholds of each index were determined as follows: amylopectin content ≥ 24.00%, total starch content ≥ 81.46%, amylose content ≥ 58.39%, head rice rate ≤ 81.83%, chalky grain rate ≥ 72.8%, Chalkiness ≥ 18.91%, transparency ≥ 47.98%. The indexes restricting amylopectin content of japonica and indica/japonica rice were significantly different from that of indica rice, and the thresholds of the above identification indexes were also predicted. The results can provide a basis for rapid screening of different types of rice varieties for brewing and evaluation of suitable raw material procurement, and provide a theoretical basis for the breeding of special rice varieties.