基于主成分分析和聚类分析综合评价蒸谷米的品质特性

为探讨蒸谷米的品质并建立其评价体系，本试验选取12个不同品种的稻谷原料制备蒸谷米，并对其碾磨品质、外观品质、营养品质、食味品质和糊化特性的品质指标进行测定分析，考察不同品种稻谷制得的蒸谷米各项品质指标之间的差异性。同时，采用主成分分析法和聚类分析法对蒸谷米的品质进行综合性评价并建立蒸谷米品质评价模型。结果表明，不同品种稻谷制得的蒸谷米各项品质指标之间均存在差异性（P<0.05），且品质指标间变异系数各不相同，说明蒸谷米在不同品质性状之间呈现不同程度的变化。由主成分分析发现23个反映不同品种稻谷制得的蒸谷米品质的指标可以用6个主成分表示，其累积方差贡献率为91.083%；根据聚类分析结果可知，爆腰率、黄米粒、外观、蛋白质、崩解值、峰值黏度、最终黏度和回生值8个品质指标可以用来综合评价蒸谷米品质的优劣。12个不同品种稻谷制得的蒸谷米中，“玉针香”的品质最佳，“大粒香”的品质最差，其次为“粤丰B”。主成分分析结合聚类分析综合评价方法可为不同品种稻谷制备蒸谷米的品质评价提供参考，并为蒸谷米专用稻的选育及蒸谷米资源的开发应用奠定理论依据。

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.