Quality Evaluation of Nine Varieties of Blueberry Based on Principal Component Analysis

To investigate the quality characteristics of different varieties of blueberry, the quality differences on appearance, physicochemical properties, and sugar and acid composition were analyzed. At the same time, correlation analysis was employed to analyze the correlation of different indexes and principal component analysis was employed to evaluate the quality characteristics of 9 varieties of blueberry. The results showed that different varieties of blueberry exhibited rich diversity in appearance, physicochemical properties, and sugar and acid composition. There was a high correlation between multiple indicators such as glucose and fructose (r=0.93), FRAP and DPPH (r=0.755). PCA results indicated that citric acid, pH, b^*, total phenol, DPPH, flavonoid and juice yield were key indicators for evaluating the quality of blueberry, and the quality characteristics of 'Canlan', 'Laigexi' and 'Shuangfeng' were excellent fruit shape index (>0.73), good solid to acid ratio of 6.12~9.57 and suitable for fresh consumption. The quality characteristics of 'Baerdewen', 'Duke' and 'Weisan' included the high in sugar, acid and antioxidant capacity, suitable for juice and wine and other products development. The flavonoid contents of 'Weisan' and 'Duke' were 1.95 and 1.62 mg/g, and the total phenol contents were 1.34 and 1.38 mg/g, respectively. The quality characteristics of 'Weisan' and 'Duke' were high content of total phenol and flavonoid, suitable for functional product development. The results above will serve an important reference to screen blueberry varieties for different purposes.