Xing Zengtao, Wang Yaosong, Feng Zhiyong, Zhao Zhihui, Liu Xinghua
Institute for Agri-food Standards and Testing Technology, Shanghai Academy of Agricultural Sciences, Shanghai 201106, People's Republic of China.
J Agric Food Chem. 2007 Oct 3;55(20):8126-32. doi: 10.1021/jf070941w. Epub 2007 Sep 12.
Hypsizygus marmoreus fruit bodies were exposed to different doses of (60)Co gamma-irradiation, stored at 4 degrees C and 65-70% relative humidity, and various physiological changes associated with postharvest deterioration, as well as the activities of selected enzymes widely considered to play a role in the process of senescence, were monitored over a subsequent storage period of 25 days. Exposure to 0.8 kGy irradiation was clearly beneficial in maintaining the postharvest appearance of the mushroom sporophores compared to non-irradiated samples and fruit bodies exposed to higher doses (1.2-2.0 kGy) of irradiation. Samples treated with 0.8 kGy also exhibited smaller initial declines in soluble protein, smaller increases in reducing sugar content, and lower levels of malondialdehyde accumulation during the early storage period. Smallest increases in proteinase activity were recorded in samples dosed with 0.8 and 2.0 kGy, and levels of superoxide dismutase were significantly higher in samples exposed to 0.8 kGy compared with non-irradiated controls. Large initial increases in catalase activity were detected in samples irradiated with 0.8, 1.2, and 1.6 kGy and, although enzyme levels gradually decreased in all samples during further storage, residual levels after 25 days were still severalfold higher in irradiated samples compared with controls. The data increase the current understanding of the effects of gamma-irradiation on the biochemical changes associated with postharvest senescence and should lead to more targeted strategies for reducing postharvest quality loss in H. marmoreus and other mushrooms.
将真姬菇子实体暴露于不同剂量的（60）Coγ射线辐照下，在4℃和相对湿度65 - 70%的条件下储存，并在随后25天的储存期内监测与采后变质相关的各种生理变化以及被广泛认为在衰老过程中起作用的特定酶的活性。与未辐照的样品以及接受更高剂量（1.2 - 2.0 kGy）辐照的子实体相比，暴露于0.8 kGy辐照明显有利于维持蘑菇子实体的采后外观。用0.8 kGy处理的样品在储存初期还表现出可溶性蛋白的初始下降幅度较小、还原糖含量的增加较小以及丙二醛积累水平较低。在剂量为0.8和2.0 kGy的样品中蛋白酶活性的增加最小，与未辐照的对照相比，暴露于0.8 kGy的样品中超氧化物歧化酶水平显著更高。在接受0.8、1.2和1.6 kGy辐照的样品中检测到过氧化氢酶活性的大幅初始增加，并且尽管在进一步储存期间所有样品中的酶水平逐渐下降，但辐照样品在25天后的残留水平仍比对照高几倍。这些数据增进了目前对γ射线辐照对与采后衰老相关的生化变化影响的理解，并应能带来更有针对性的策略以减少真姬菇和其他蘑菇的采后质量损失。
