Abstract:Contents of several compounds (polyphenols, Vc, etc.) in fresh peach juice made by heating at high pressure during 120-day storage were analyzed by HPLC. It was found that the oxidation and polymerization of polyphenols mainly accounted for the non-enzymatic browning of peach juice during the storage, which could be avoided by low-temperature storage of the juice. The non-enzymatic browning of the juice was enhanced and the loss of polymeric proanthocyanidin, epicatechin, chlorogenic acid and Vc in the juice increased by increasing the storage time and temperature. During the storage of the juice, L* value decreased, a* value increased and b value changed little. Free amino acids also contributed to the browning of juice. Besides, the mean degree of polymerization for polymeric proanthocyanidin increased as improving the storage time and temperature. The size distribution analysis showed that new particles formed during the storage of juice.
