Effect of antioxidant activity and change in quality of chemical composition and polyphenol compound during long-term storage

摘要

Changes in polyphenol, free sugar, and organic acid concentrations and their antioxidative activities in Korean pear during storage were investigated. The antioxidant activity of polyphenols was evaluated. Polyphenol concentration in different partsof pear, peel, pulp and core, reached 25.7 percent. pH decreased while concentrations of free sugars, including fructose, glucose, and sucrose, increased during storage. Four organic acids, citric, malic, succinic, and fumaric acids, were determined. Succinic acid was the major organic acid in the pulp and decreased after 5 month of storage. The antioxidative activities of polyphenol fractions I, II, and III on cottonseed, linseed, and fish oils were higher than those of the control group.