Inhibitory Effects of 1-MCP and DPA on Superficial Scald of Dangshansuli Pear

Dangshansuli pear is one of crisp pears and has a non-climacteric respiratory pattern. Dangshansuli pear fruits were treated with 1 000 or 2 000 uL L-1 diphenylamine (DPA) for 1 min, or with 0.5 uL L-1 1-methylcyclopropene (1-MCP) for 12 h before cold storage at (2±0.5)°C for up to 210 d. Incidences of superficial scald and related physiological indexes were investigated during storage. The results showed that superficial scald occurred in control fruit with a rate of over 90% after 210 d at cold storage plus 10 d at room temperature. Treatments with 1 000 and 2 000 uL L-1 DPA and 0.5 uL L-11-MCP inhibited the accumulation of a-farnesene, conjugated trienes, total phenolic contents, and malondialdehyde (MDA) during storage. The treatments also decreased leakage of cell membrane and the activity of polyphenol oxidase (PPO) in the peel. These results indicate that 1-MCP and DPA treatments inhibit and postpone the occurrence of superficial scald of Dangshansuli pears remarkably in cold storage and post-storage shelf life, respectively, while the mechanisms were different. The results above may provide a theoretical evidence for the agriculture production.