Effects Of Preharvest Bagging And Postharvest Treatments Of 1-MCP, GSH On Quality In 'Ya' Pear Fruit

In our research, effects of preharvest bagging or postharvest treatments of 1-Methylcyclopropene (1-MCP) and glutathione (GSH) on quality, physiology metabolism and brown heart in 'Ya' pear (Pyrus bertschneideri Reld.) fruit were investigated during storage.Results showed that decrease in Ya pear fruit firmness and soluble solids content (SSC) was inhibited and stem brown index was reduced by treatments with different concentrations of 1 -MCP (0, 0.01, 0.1, 0.2, or 0.5 μL/L) or different time of 1-MCP exposure for 12, 24, or 48 h, respectively, and stored at 20 ± 2 ℃, 85~95%RH.The most significant inhibition of fruit ripening of pear was obtained by the treatment with 0.1 μl/L 1 -MCP exposure for 48 h.Pear fruit was treated with 0.1 μL/L 1-MCP after harvest at 20 ±2 ℃ with 85-95% RH before storage (20 ℃). Results showed that 1-MCP effectively inhibited the ethylene evolution and respiration rate and ethylene climactic peak was also delayed. 1-MCP effectively remained the firmness and delayed the decline in titratable acid (TA) of the storage. Changes in antioxidant content and antioxidant enzymes were also estimated and reduced by 1-MCP. Furthermore the appearance of senescence BH and decay in pear were reduced by the treatment with 1-MCP.Pear fruit was treated with 500 mg/L GSH after harvest at 20±2 ℃ with 85-95% RH before storage (20 °C). Results indicated that GSH delayed the loss of fruit firmness, but had no obviously effect on other quality parameters. And GSH effectively reduced the appearance of brown heart, stem brown index and decay in pear fruit.Pear fruit bagged about one month after full flowering were harvested and stored at 20 ± 2 °C with 85-95% RH. Results showed that preharvest bagging effectively delayed the ethylene climactic peak in pear fruit but the ethylene evolution and respiration rate was not remarkably affected. Firmness and TA in bagged pear fruit was higher, but SSC and sugar content was lower than the un-bagged control fruit. Results indicated that preharvest bagging effectively increased the GSH content and decreased the activity of SOD, CAT and POD in ' Ya' pear fruit. Furthermore it reduced the PPO activity and phenolic compounds. As the result, the appearance of senescence BH and decay in bagging pear were absolutely lower than the control fruit.