Polyphenolic Compound and Substances Determination of Enzymatic Browning in Pear

The phenolic compound content,categories,and substrate for enzymatic browning in 10 cultivars,which belong to different species and inter-specific hybridization of pear(Pyrus L.)in China, were investigated intensively in this paper. The results showed that 10 different phenolic compounds were identified in fresh fruit with high performance liquid chromatography(HPLC)analysis. The content of phenolic compounds exhibited high difference among different cultivars and species,and average content of chlorogenic acid was the highest,and followed by vanillin,violaquereitrin,epicatechin and catechin in sequence. Thus,these five phenolic compounds were major phenolic substances in pear fruit;Whereas, average content of caffeic acid was the lowest. The gray correlation of total phenols,chlorogenic acid, epicatechin,catechin and antioxidative activity with browning revealed that total phenols showed the primary effects on browing and followed by chlorogenic acid. Comparatively,the antioxidative activity showed the lowest effect on browning. Chlorogenic acid should be the primary browning substance because of the highest content in fruit and capacity in combination with polyphenol oxidases(PPO).