Research On Relativity Between Rice’s Physical-chemical Properties And Edible Quality

As the main food of Chinese, rice is various. The method for judging diversity of different rice’s tasting quality is very important for researcher on cereals. The traditional way sensory evaluation is in the boundness of human’s subjective judgment, and it is difficult to the evaluation results objectively or accurately. So, to find a method for judging rice’s tasting quality is quite important.Sensory evaluation and3kinds of physic-chemical analysis which include raw rice’s agronomic characters analysis, cooked rice’s physic-chemical analysis, texture analysis were carried out. Regression analysis and PCA were carried out on the4kinds of indexes, and correlation analysis was carried out respectively between the3kinds of physic-chemical indexes and sensory evaluation indexes, for exploring the relationship between physic-chemical indexes and sensor evaluation indexes, so to replace the evaluation of sense with physic-chemical indexes for judging rice’s tasting quality objectively and accurately. Main results are as follow.1. By variance analysis, the results indicate that there existing obvious genetic difference in agronomic characters indexes, cooked characters indexes, texture indexes and sensory evaluation indexes of8kinds of rice.2. By correlation analysis and regression analysis, the results indicate that every sensory evaluation index has significant correlation with at least1physic-chemical index. Sensory hardness has very significant positive correlation with light transparency difference, very significant negative correlation with moisture and significant positive correlation with protein content. Sensory spring has very significant positive correlation with amylose and protein content and very significant negative correlation with light transmittance in rice soup. Sensory viscosity has significant negative correlation with chalkiness degree. Palatability has very significant negative correlation with amylose content and very significant negative correlation with light transparency difference. Flavor has significant correlation with amylose content and cohesiveness. Odour has very significant positive correlation with fat, protein content and dry matter in rice soup, very significant negative correlation with chewiness and significant positive correlation with light transmittance in rice soup. Sensory luster has very significant positive correlation with amylose content and light transparency difference, very significant negative correlation with light transmittance in rice soup, significant positive correlation with chalkiness degree and cohesiveness and significant negative correlation with resilience. Grain integrity has very significant positive correlation with amylose content and resilience, very significant negative correlation with water absorption and significant negative correlation with iodine content. Sensory color has very significant negative correlation with fat content, chalky grain percentage, hardness, tackiness and resilience, significant positive correlation with cohesiveness. Appearance evaluation has very significant positive correlation with light transmittance in iodine solution and light transparency difference, very significant negative correlation with water absorption and transmittance in rice soup, and significant positive correlation with iodine content. Cool texture has very significant negative correlation with moisture. Total evaluation has very significant positive correlation with light transmittance in iodine solution, very significant negative correlation with iodine content, and significant positive correlation with amylose content.3. By principal component analysis, the results indicate that the cumulative of the selected5principal components from22physical-chemical indexes influencing cooked rice’s sensory indexes reaches to97.46percent, so the5components can evaluate the edible quality of rice instead of physical-chemical indexes.