Study on non-enzymatic browning of pear juice of different cultivars in storage

【Objective】To explain the characteristics of Maillard reaction with pear juice of different varieties during storage.【Method】The 10 cultivars were used as experimental materials to study the changes of main materials of non-enzymatic browning in pear juice.【Result】Results showed the browning degree of different pear juice rose all together during storage time at 25 ℃.The browning degree rose fast at the earlier stage and rose smoothly at the later stage.‘Housui' was most seriously browning and‘dahebai' was the least browning after storing 35 d at 25 ℃.The 5-HMF content of 10 cultivar juice increased significantly during storage;the value of pH and the ammoniacal nitrogen content of of 10 cultivar juices decreased during storage;the TSS content of 10 cultivar juices changed irregularly during storage;reducing sugar content of juices of 10 cultivars increased early and decreased finally.The 5-HMF and reducing sugar content had positive correlation with browning degree;the value of pH,TSS and ammoniacal nitrogen content had passive correlation with browning degree.【Conclusion】The pear juice of ‘Xibaqingshui' and ‘Xinxiang' were good for storage,and the pear juice of sensory quality and nutritional quality changed less than other varieties during stored,they were excellent varieties for storage.