Abstract: In the present study, the fruit quality of 22 blueberry varieties introduced in Shandong province was analyzed and comprehensively evaluated. The results showed that nine quality indicators were greatly different among different blueberry varieties. The coefficients of variation (CVs) for single fruit mass, specific gravity, hardness, soluble solid content, valid acidity value (pH), anthocyanin content and vitamin C content were greater than 10.00%, indicating significant differences between varieties. Meanwhile, the CVs for fruit shape index and peel brightness index (L* value) were less than 10.00%, suggesting that they were more stable indicators. Five quality indicators including fruit shape index, hardness, L* value, soluble solids content and pH were screened out by using correlation analysis and principal component analysis (PCA) as the core indicators to comprehensively evaluate the fruit quality of different blueberry varieties. The analytical hierarchy process was applied for weight analysis of the core indexes, and a mathematic model was established to calculate the comprehensive evaluation index and evaluate the fruit quality and processing suitability of each blueberry cultivar. Moreover, according to the main quality indexes of blueberry, cluster analysis (CA) was carried out by using the Pearson correlation method. Consistent results were obtained using PCA and CA, indicating that both can be used to analyze blueberry fruit quality index and comprehensively evaluate the fruit quality and processing suitability of different blueberry varieties.

Key words: blueberry, quality characteristics, core indicators, coefficient of variation, principal component analysis, cluster analysis