Quality characteristics of nine kiwifruit varieties cultivated in Sichuan

To clarify the characteristics of kiwifruit varieties in Sichuan, eight commercialized varieties and one native wild variety were selected as research subjects. The color, physicochemical properties, antioxidant activity, sugar and acid compositions and volatile compounds of nine varieties of kiwifruit were analyzed. The results revealed that the quality characteristics of the 9 varieties were diverse. Ruiyu and Hongyang presented the highest pH values (5.79 and 4.81), highest soluble solids contents (SSCs) (17.68 ° Brix and 16.37 ° Brix), higher sugar levels, sugar‒acid ratios (SRs) and maturity indices (MIs) and lower titratable acidity (TA) levels (1.33 g/L and 1.42 g/L) and organic acid contents, which are suitable for ready-to-eat consumption. Jinshi-4 presented the highest total phenolic content (TPC) (98.95 mg RE/100 g), total flavonoid content (TFC) (34.55 mg GAE/100 g), and vitamin C (Vc) (50.90 μg/mg) and the strongest antioxidant activity, which is suitable for health product production. Furthermore, Hayward, Donghong and Jinyan had prominent fruity, floral grassy, and fresh flavors because of their high levels of ethyl butanoate, ethyl hexanoate, methyl benzoate, 2-hexen-1-ol (E)-, 2-octanol, (S)-, 2-hexenal, hexanal and linalool, making them ideal varieties for processing into juice, wine, fruit vinegar and other products. In conclusion, this study provides important guidelines for selecting kiwifruit varieties for different applications and presents significant implications for the cultivation, variety selection, industrial enhancement, and overall industry development of kiwifruit. • 9 varieties of kiwifruits are different in color, soluble solids content, titratable acid, sugar and organic acid composition, as well as antioxidant activities. • The terpenoids, alcohols and esters cause the differences of volatile compounds among the 9 varieties of kiwifruits. • GC-MS combined with PCA, scatter plot of the loadings, VIP values and heat-map can effectively distinguish among 9 varieties of kiwifruits.