Pre-Storage Treatment with Hypoxia or 1-MCP to Maintain 'Spadona' Pear Quality after Cold Storage

The 'Spadona' pear (Pyrus communis) grown in Israel is susceptible to two physiological disorders that develop in cold storage, superficial scald and internal browning. Application of hypoxia as a low-O-2 stress (LO2) for 7 d at 20 degrees C or 1-MCP (0.6 ppm for 20 h) to 'Spadona' pears, prior to cold storage, were both effective in inhibiting these disorders, thus maintaining fruit quality for up to 4.5 months in regular air (RA) cold storage at 0 degrees C plus 5 d shelf life at 20 degrees C. The effectiveness of LO2 was higher when the O-2 levels during treatment were kept below 0.5%, enabling accumulation of CO2, acetaldehyde and ethanol, while no ethylene was produced. If ethylene accumulated in the chamber headspace during treatment, the effectiveness of LO2 treatment was reduced and alpha-farnesene was produced later in storage, leading to more scald. The levels of alpha-farnesene in 'Spadona' peel after 2 months RA storage correlated negatively with fruit firmness and positively with fruit yellowing, indicating a delay in senescence. The 1-MCP treated fruit exhibited the best fruit quality and taste attributes after 4.5 months in RA storage plus 5 d shelf life. However, the LO2 treatment can serve as an organic alternative to 1-MCP, due to the fact that it maintained fruit firmness, green color and crispness. In addition, 1-MCP and LO2 treated fruit, did not exhibit internal browning around the seed cavity, which is a typical senescence disorder in pear, after 4.5 months RA cold storage and 5 d shelf life.