Physical Characterization, Nutrient, Phenolic Profiles and Antioxidant Activities of 16 litchi Cultivars Grown in the Upper Yangtze River Region

Litchi grown in the upper Yangtze River region have the advantage of being late-maturing owing to the geographical location. This study aimed to evaluate the physical characteristics, nutritional values, phenolic composition and antioxidant activities of 16 litchi cultivars grown in the upper Yangtze River region. Litchi grown in this region had total soluble solid and ascorbic acid contents comparable with those of cultivars grown in other locations. The total polyphenol contents were determined using the Folin-Ciocalteu assay, and the phenolic profiles were determined using UPLC-QqQ-MS/MS. Nine phenolic compounds were identified and quantified in this study. Naringin, rutin and p-coumaric acid were the major phenolic compounds in all the litchi cultivars. Statistical analysis of all the physiochemical results was performed using principal component analysis. Our results indicated that litchi grown in the upper Yangtze River region not only showed the late-maturity characteristic but were also good dietary sources of phenolic compounds and antioxidants. In particular, 'Fei Zi Xiao' and 'Jing Gang Hong Nuo', characterized by high polyphenol contents and high antioxidant capacities, were of superior comprehensive quality. This study provides important information for the development of late-maturing litchi industry.