Comprehensive Evaluation of Blueberry Quality Based on Principal Component Analysis and Cluster Analysis

Objective: To explore the comprehensive quality characteristics of blueberries. Methods: 20 indexes including sensory morphology, nutritional function, free amino acids and volatile flavor substance content of six varieties of blueberries in Sichuan were detected by automatic amino acid analyzer and gas chromatography-mass spectrometry and other instruments. Furthermore, its comprehensive quality was evaluated by the principal component analysis and cluster analysis. Results: There were differences among different blueberry varieties. The single fruit weight (2.06 g) and transverse diameter (14.39 mm) of Brigita were the highest, while the gumminess (151.96 N) and total phenol content (1.64 mg/g) were the lowest; Mistry had the highest free amino acid content (453.72 mg/100 g), and the proportion of umami and sweet amino acids was higher; Emerald had the lowest free amino acid content (122.93 mg/100 g) and the least variety; Gardenblue had moderate hardness, its sugar-acid ratio (28.23), anthocyanin content (2.09 mg/g), total phenol content (5.78 mg/g) and flavor substances content (14.60 μg/g) were the highest. Conclusions: According to principal component analysis, the optimal variety was Gardenblue. Cluster analysis divided blueberries into three categories, suitable for fresh-eating varieties including Gardenblue and Legacy; suitable for both processing and fresh-eating varieties were Emerald, Brigitta and Misty; while Bluerain had outstanding processing advantages.