1-MCP对不同成熟度猕猴桃电特性的影响

摘要

In this study, ＇Hayward＇ kiwifruit at the appropriate harvest （maturity Ⅰ, with a TSS of 6.2%） and late harvest （maturity Ⅱ, with a TSS of 8.8%） was used to investigate the effect of 0.5μL/L 1-methylcyclopropene （1-MCP） on postharvest electric properties of fruits at room temperature （20 ℃）. Kiwifruits at maturity I revealed a remarkable increased in impedance （Z） at the frequency of 1 MHz when compared with those at maturity II and a significant difference in Z value began appearing on storage day 7 （P 〈0.05）. The same results were observed for capacitance in the parallel equivalent circuit mode （Cp） at 10 kHz. 1-MCP inhibited the decrease of Z value in kiwifruit with prolonged storage period at 0.1 kHz or 1 MHz. 1-MCP-treated kiwifruit presented a significantly higher Cp at 10 MHz than the control. However, inductance in parallel equivalent circuit mode （Lp） and impedance phase angle （θ） had insensitive response to fruit maturity and 1-MCP, and consequently was not a measure of maturity and 1 MHz treatment or not.%以适期采收（成熟度Ⅰ，可溶性固形物6．2％）和晚采收（成熟度Ⅱ，可溶性固形物8．8％）的‘海沃德’猕猴桃为试材，研究0．5L／L1-MCP处理对在室温（20℃）贮藏条件下果实电特性的影响。结果表明，在1MHz频率下，成熟度Ⅰ的果实复阻抗明显高于成熟度Ⅱ的果实，而且从贮藏7d开始，两成熟度果实复阻抗（Z）值差异达显著水平（P〈0．05）。在10kHz频率下，成熟度Ⅰ果实并联等效电容（Cp）值明显高于成熟度Ⅱ的果实，而且从贮藏7d开始，两成熟度果实C。值差异达显著水平（P〈0．05）。在0．1kHz和1MHz电激励频率条件下，随着贮藏时间的延长，1-MCP有抑制果实复阻抗下降的趋势；在10kHz频率条件下，1-MCP处理果Cp值明显高于对照果；但并联等效电感（Lp）和阻抗相角（θ）对成熟度和1-MCP处理的响应不灵敏，不能作为区分成熟度或1-MCP处理的敏感电参数。