[Objective]The aim of the research was to provide theoretical support for controlling and delaying the decrease of ascorbic acid ( ASA) content in post-harvest fruit and vegetable. [ Method j With post-harvest red globe grape and green pepper as test materials, the effect of heat shock and storage temperature on the variation of their ASA contents and metabolism-related enzyme activities was researched. [ Result]The decrease of ASA contents in green pepper and red globe grape at 15 ℃ was slower than that at 25 ℃. After heat shock treatment of 10 min,the ASA content in red globe grape was increased instantaneously and then rapidly decreased and that in green pepper got partial loss. It was indicated that heat shock treatment could not delay the decrease of ASA content in red globe grape effectively,but it could delay the decrease of ASA content in green pepper and enhance its storage quality. The activities of both ascorbate peroxidase (APX) and ascorbic acid oxidase (AAO) showed decreasing trend at different temperatures. After heat shock treatment of 10 min.the instantaneous decrease of activities of APX and AAO in red globe grape and AAO in green pepper was obvious,the activities of ascorbate reductase in red globe grape and green pepper was enhanced instantaneously and then rapidly decreased, the activity of mono - dehydroascorbate reductase (MDAR) in red globe grape was enhanced and that in green pepper was decreased. [Conclusion]During storage,the activity of DHAR may be an important factor influencing the variation of ASA content.%[目的]为控制和延缓采后果蔬抗坏血酸(ASA)含量的下降提供理论支持.[方法]以采后红提和青椒为试材,研究热激和储藏温度对其ASA含量及代谢相关酶活性变化的影响.[结果]15℃下青椒和红提的ASA含量下降比25 ℃下慢.经过10 min热激处理后,红提的ASA含量瞬间上升,随后迅速下降；青椒中ASA含量有部分损失.说明热激处理不能有效延缓红提ASA含量的下降,可以延缓青椒ASA含量的下降,提高青椒贮藏品质.不同温度下抗坏血酸过氧化物酶(APX)和抗坏血酸氧化酶(AAO)活性均呈下降趋势.经过10 min热激处理后,红提的APX和AAO以及青椒的AAO活性瞬间下降明显,红提和青椒中脱氢抗坏血酸还原酶(DHAR)活性瞬间提高,随后迅速降低;而红提中单脱氢抗坏血酸还原酶(MDAR)活性提高,青椒中MDAR活性降低.[结论]在储藏过程中,DHAR的活性可能是影响ASA含量变化的重要因素.
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