高CO_2短时处理对茎瘤芥采后衰老的影响

Effects of Short-term High CO_2 Treatment on Senescence of Postharvest Tumorous Stem Mustard

目的以茎瘤芥为试材,研究不同浓度的高CO2短时处理对新鲜茎瘤芥采后衰老的影响。方法将预冷后的茎瘤芥分别充入CO2（30%）＋N2（70%）,CO2（40%）＋N2（60%）,CO2（50%）＋N2（50%）等3种混合气体（均用体积分数表示）,以相同条件下充入空气的处理作为对照,然后置于温度为（4±1）℃、相对湿度为90%~95%的气候箱中处理48 h。结束处理的茎瘤芥用厚度为0.03 mm的聚乙烯袋包装,置于温度为（4±1）℃、相对湿度为90%~95%的条件下贮藏,定期测定其呼吸强度、衰老相关酶活性、VC含量等指标。结果高CO2（30%,40%,50%）短时处理可有效降低茎瘤芥的呼吸强度,高CO2（30%,40%）处理使贮藏后期的茎瘤芥果皮保持了较高的超氧化物歧化酶（SOD）和过氧化氢酶（CAT）活性,同时抑制了果皮过氧化物酶（POD）、多酚氧化酶（PPO）活性上升和果皮VC含量的降低,高CO2（40%）短时处理效果最明显;高CO2处理对于茎瘤芥果肉衰老相关指标无显著影响。结论高CO2（40%）短时处理能有效延缓茎瘤芥采后衰老进程,保鲜效果最好。

Effects of short-term high CO2 treatment at different concentrations （30% and 40% and 50% ） on the senescence of postharvest tumorous stem mustard were investigated. Fresh tumorous stem mustards were treated with mixed gas of CO2（30% ） ＋ N2（70%）, CO2（40% ） ＋ N2（60%） and CO2（50% ） ＋ N2（50%） respectively after pre-cooling, using ambient atmosphere as the control, and stored in Climate box at （4 ± 1） ℃ and 90% -95% relative humidity （RH） for 48 h. After short-term CO2 treatment, tumorous stem mustards were stored in polyethylene package with a thickness of 0.03 mm at （4 ± 1） ℃ and 90%-95% RH, and the respiration intensity, activity of senescence-related enzyme, Vitamin C content were determined at regular time interval during the storage. The experimental results showed that short-term high CO2 treatment at the concentrations of 30% and 40% and 50% could significantly reduce the respiration intensity of tumorous stem mustards. Short-term high CO2 at the concentrations of 30% and 40% could keep higher activities of superoxide dismutase （SOD）, catalase （CAT）, and inhibit the increase of peroxidase （POD） and polyphenol oxidase （PPO） activities as well as the decline of Vitamin C content in peel of tumorous stem mustards. The effect of short-term CO2 at the concentrations of 40% was the most remarkable. However, short-term high CO2 treatment could not obviously affect the senescence-related indicators of tumorous stem mustard pulp. Short-term high CO2 at the concentrations of 40% could delay the senescence progress of postharvest tumorous stem mustard.