Abstract:

Objective: The aim of this study was to evaluate the contents of total polyphenols and total flavones and in vitro antioxidantactivity in crabapple fruits. Methods: Crabapple fruits from 14 varieties were evaluated in this study. 1,1-diphenyl-2-picrylhydrazylradical 2,2-diphenyl-1-(2,4,6-trinitrophenyl) hydrazyl (DPPH), 2,2’-azinobis-(3-ethylbenzthiazoline-6-sulphonate) (ABTS) andferric ion reducing antioxidant power (FRAP) methods were used to evaluate in vitro antioxidant activity of the fruits. The content ofpolyphenols was measured using the Folin-Ciocalteau method. The composition of polyphenol extracts was also analyzed using highperformance liquid chromatography (HPLC). Correlation between polyphenol content and antioxidant capacity was analyzed. Principalcomponent analysis (PCA) and hierarchical cluster analysis (HCA) were also used to classify the tested crabapples. Results: Totalpolyphenols and total flavones of the crabapples were 62.96–287.86 mg GAE per 100 g of fresh fruits and 83.77–604.11 mg RE per 100 gof fresh fruits, respectively, which were similar to the reported levels in apple skin. Comparatively, Chaenomeles speciosa had the highestvalues of total polyphenol content, total flavone content and in vitro antioxidant activity, which was followed by Malus halliana Koehne.A total of 13 polyphenols, including chlorogenic acid, epicatechin, rutin and phlorizin were identified in the tested crabapples. Antioxidantcapacity was significant positively correlated with the contents of total polyphenols and total flavones. The 14 crabapple varietieswere classed into three clusters in the PCA analysis on the basis of the contents and composition of polyphenols. Cluster A had highcontents of chlorogenic acid, Cluster B had high contents of catechin, rutin and phlorizin and Cluster C had high contents of epicatechinand hyperosode. The crabapples with vanilla acid were also in cluster C. Conclusion: Crabapple is a rich source of polyphenols, andChaenomeles speciosa has the highest value of total polyphenol content and in vitro antioxidant activ

Key words: crabapple, polyphenols, flavones, in vitro antioxidant activity, principal component analysis (PCA), hierarchical cluster analysis (HCA)