A Evaluation Model Of Eating Quality For Japonica Rice From Heilongjiang Province

Heilongjiang Province is located in the northeastern part of China in sub-arctic region, has one of only three black soil zones in the world. Quality of japonica rice in Heilongjiang Province is one of the best. With the improvement of people’s living standards, people’s attitude towards eating was being changing from eating to eating well. In order to meet the market demand, to find a scientific and effective evaluation method of rice eating quality is necessary. In this study,15varieties of japonica rice grown in Heilongjiang province were chosen and investigated. Their physical and chemical properties, cooking properties and textural features were determined. And their eating qualities were measured by sensory evaluation method. Correlation analysis between physicochemical properties, pasting properties, texture characteristics and eating quality was researched. A normal Principal Component Analysis (PCA) was used to investigate the properties of rice quality.The main findings are as follows:1. Differences among qualities of15varieties of japonica rice grown in Heilongjiang province. The result of16properties including amylose, protein, fat, water, gelatinization temperature, breakdown, setback, hardness, adhesiveness, cohesiveness explained that the characteristics show significant difference between different kinds of rice. Moreover, in the physical and chemical properties, the fat content, adhesive strength, amylose content had great differences; between textural properties, chewiness, resilience, had great differences in the viscosity of species; in pasting properties, the highest viscosity, low viscosity had significant differences between species.2. Correlation analysis between rice characteristics and eating quality of rice. Pearson correlation analysis was used to explain the correction of rice characteristics and eating quality of rice.The results showed that:The content of protein was significantly positively correlated with the smell and color (p≤0.05); was significantly positively correlated with cold rice texture (p≤0.05). Rice moisture content was significantly negatively correlated with integrity (p S0.05). Starch content was significantly negatively with stickness (p≤0.05); was very significantly negatively correlated with flexibility (p≤0.01). Amylose content was very significantly positively correlated with stickness, hardness, cold rice texture, taste (p≤0.01); was significantly positively correlated with flexibility (p≤0.05). Adhesive strength was very significantly positively correlated with integrity, stickness, hardness, taste and texture of cold rice (p≤0.01); was significantly positively correlated with flexibility (p≤0.05). Fat content had a significant negative correlation with color (p≤0.05); had a very significant positive correlation with gloss, flexibility (p≤0.01).In textural properties, hardness was significantly negatively correlated with integrity, firmness of eating quality (p≤0.05). Flexibility, cohesiveness, chewiness, resilience had a significant correlation with eating qualities (p≤0.05); cohesiveness had a extreme significant correlation with flexibility, firmness of eating quality, taste, cold rice texture (p≤0.01). In gelatinization properties, pasting temperature was very significantly negatively correlated with firmness of eating quality, taste (p≤0.01). Breakdown was very significantly negatively correlated with taste, cold rice texture, firmness of eating quality (p≤0.01). Setback had a very significantly negatively correlation with stickness, taste, cold rice texture firmness of eating quality (p≤0.01).3. A evalutation model of eating quality for japonica rice grown in Heilongjiang Province. A normal Principal Component Analysis (PCA) was used to analyse properties of15varieties of japonica rice. The result of PCA reported that the dedication from the first to fifth principal component was43.59%,14.19%,9.22%,8.54%and6.44%, respectively, and the accumulative dedication was81.98%. An evaluation model of eating quality of japonica rice grown in Heilongjiang Province was established in the method of principal component analysis (PCA). The consistency of result of eating qualities evaluated by the model and sensory evaluation method was80%.