Polyphenolic Components and Composition Differences of Fruit Polyphenols in Apple Landraces Grown in Cold Regions

The composition and content of polyphenols in fruit pericarp and pulp  of 12 Apple landraces grown  of Heilongjiang Province were determined by ultra-high performance liquid chromatography (UPLC), and the differences in the composition and content characteristics of polyphenols in different varieties were studied, and the main factor analysis and cluster analysis were carried out. The results showed that 5 kinds of 20 kinds of polyphenols were detected in 12 Apple landraces , the main phenolic substances in pericarp were epicatechin and catechin, and the main phenolic substances in pulp were chlorogenic acid, catechin and procyanidin. There were significant differences in the composition and content of polyphenols among different varieties, the smallest coefficient of variation was quercetin 3-glucoside (37.48%), and the largest coefficient of variation was rutin (267.18%). It was found that the content of proanthocyanidins in pericarp and pulp was higher by principal component analysis. Based on the content of polyphenol components, it was found that the results of pulp clustering were more consistent with the field phenotypic identification results and kinship. The results provide data support and theoretical basis for processing and utilization of phenolic substances and breeding of local varieties in Heilongjiang province.