Effects of Different Temperatures on the Fruit Softening of Xizhoumi No. 25 Hami Melon during Storage

【Objective】 To study the effect of different storage temperatures on cell wall degradation enzymes in pulp of Xizhoumi No.25 Hami melon and explore the mechanism of temperature regulation on postharvest softening of the melon in the hope of providing theoretical reference for postharvest storage and preservation of Hami melon. 【Method】 The mature Xizhoumi No.25 Hami melon was taken as test material and stored in different temperatures (0℃,5℃,10℃,15℃), the fruit hardness and respiratory intensity were measured every 5 days. The effects of different storage temperatures on fruit softening were analyzed by analyzing the activity indexes of cell wall degradation enzymes such as β-galact osidase (β-Gal), polygalacturonase (PG), pectinase (PE) and cellulose (Cx). 【Result】 The effects of different storage temperatures on fruit hardness, respiration intensity and cell wall degradation enzyme activity of Xizhoumi No.25 Hami melon were significantly different. The lower the temperature was, the slower the pulp hardness decreased, the lower the peak value of fruit respiration intensity, and the lower the activity of pulp cell wall degradation enzyme. When the temperature was lower than 5℃,the pulp showed obvious symptoms of cold injury. 【Conclusion】 All things considered, 5℃ is the best for Xizhoumi No.25 Hami melon storage. The results of correlation analysis showed that the fruit hardness of Xizhoumi No.25 is negatively correlated with respiratory strength, and significantly negatively correlated with β-Gal, PG, PE and Cx activities.