脉冲微波对大米寄生曲霉致死效应研究.pdf

现代食品科技 Modern Food Science and Technology 2015, Vol.31, No.7 脉冲微波对大米寄生曲霉致死效应的研究 曾淑薇，黄晶晶，赵思明，车丽，黄琪琳 （华中农业大学食品科学技术学院，环境食品学教育部重点实验室，湖北武汉 430070 ） 摘要：以大米污染物寄生曲霉为研究对象，分析了脉冲微波剂量、脉冲宽度、微波总时间、间歇时间对寄生曲霉生长、细胞通 透性以及表面形态的影响及规律，以期为大米储藏过程中寄生霉菌的微波控制提供理论依据。研究结果及结论如下：随着脉冲微波强 度的增加，霉菌的蛋白质和核酸渗透量、电解质渗透率以及细胞内 Ca2+的荧光强度呈先增大后减小的趋势，说明脉冲微波可引起寄 生曲霉的细胞膜出现电穿孔，导致其细胞内物质溶出量突然增大，而且推测出脉冲微波灭霉的热效应和非热效应的临界条件为微波剂 量5~7.5 W/g、脉宽200 ms、微波总时间20 s、间歇时间150 ms。超越临界条件，脉冲微波处理可导致寄生曲霉生长量显著降低，对 其生长有明显的抑制作用。脉冲微波处理后寄生曲霉表面形态发生卷曲皱缩，进一步证实脉冲微波可改变寄生曲霉的细胞膜及其通透 性。 关键词：脉冲微波；寄生曲霉；生长曲线；细胞膜通透性 文章篇号：1673-9078(2015)7-86-91 DOI: 10.13982/j.mfst.1673-9078.2015.7.015 Effects of Pulsed Microwaves on Aspergillus parasiticus in Rice ZENG Shu-wei, HUANG Jing-jing, ZHAO Si-ming, CHE Li, HUAGN Qi-lin (College of Food Science and Technology and MOE Key Laboratory of Environment Correlative Dietology, Huazhong Agricultural University, Wuhan 430070, China) Abstract: The potential application of pulsed microwave radiation in the control of Aspergillus parasiticus growth in rice during storage was evaluated in terms of fungal growth and cell membrane permeability. The parameters evaluated were microwave dose, pulse width, total time, and interval time. The results showed that fungal DNA, protein, and electrolyte leakage, as well as intracellular Ca2+ fluorescence intensity, of A. parasiticus increased with an increase in microwave intensity, followed by a slight decrease. This indicated that pulsed microwaves could cause electroporation of the cell membrane, leading to increased cell membrane permeability and accelerated leakage of the cytoplasm. Moreover, threshold values of pulsed microwave irradiation on A. parasiticus under thermal and non-therma