Comprehensive Evaluation of Quality Characteristics of Parboiled Rice Based on Principal Component Analysis and Cluster Analysis

In order to explore the nutritional value of parboiled rice and establish a parboiled rice quality evaluation system, 12 rice varieties were selected to prepare the parboiled rice. The quality attributes of parboiled rice were analyzed for milling quality, appearance quality, nutritional quality, taste quality and gelatinization properties, and the differences of the quality indexes in parboiled rice prepared by different rice cultivars were investigated. The quality of parboiled rice was comprehensively evaluated by principal component analysis (PCA) and cluster analysis (CA), and the evaluation model of parboiled rice quality was established. The results showed that there were significant differences in quality indexes among parboiled rice (P<0.05), and the coefficient of variation of the quality indexes were different, indicating that the parboiled rice presented varieties between different quality attributes. PCA showed that six principal components represented the 23 quality indicators parboiled rice, making 91.083% cumulative contribution to the total variance. According to the cluster analysis, eight quality indexes including the crack ratio, yellow rice, appearance, protein, the breakdown, the peak viscosity, the final viscosity and setback first were sufficient to evaluate the quality of parboiled rice. Among the parboiled rice prepared by 12 rice cultivars, the parboiled rice of ‘Yuzhenxiang’ had the best quality, and that of ‘Dalixiang’ had the worst quality, followed by ‘Yuefeng B’. The comprehensive evaluation method of principal component analysis and cluster analysis can provide reference for the quality evaluation of parboiled rice prepared by different rice varieties, and provide theoretical basis for the breeding of special rice for parboiled rice, and the development and utilization of the germplasm resources of parboiled rice.