为了探讨微波杀灭玉米霉菌过程中是否存在非热效应，对烟曲霉、黑曲霉、产黄青霉和桔青霉等四种霉菌微波处理前后的菌体生长情况进行研究。通过霉菌菌体生长量的测定建立了生长模型，对蛋白质和DNA的吸光度值以及电解质的渗透率进行测定，同时应用原子力显微镜观察微波处理前后黑曲霉孢子的形态变化以及渗出物情况。结果表明：与相同温度的水浴加热相比，微波处理后霉菌生长的延滞期较长、种群容纳量较低，蛋白质、DNA的吸光度值和电解质的渗透率较高，说明相同温度下微波处理对霉菌的伤害要大于水浴，杀菌过程中存在非热效应。应用原子力显微观察发现，微波处理前后黑曲霉孢子的形态差异较大，未处理的黑曲霉孢子体态饱满且表面较为平整，处理后孢子表面产生皱缩；经微波处理后孢子细胞内溶物渗出较多，说明微波处理对孢子细胞膜有一定的破坏作用

In order to discuss the presence of non-thermal effect during the process of killing molds in corn by microwave treatment, growth situation of Aspergillus funigatus, Aspergillus niger, Penicillium chrysogenum and Penicillium citrinum before and after microwave treatment were studied. The growth models of molds were established through the determination of mold growth amount, the absorbance values of protein and DNA, the permeability of electrolyte, and morphological changes of A. niger spore and situation of exudates were observed by atomic force microscope (AFM). Results showed that the lag phases of four kinds of molds became longer, population capacities lessened, and absorbance values of protein and DNA largened after microwave treatment, compared with water bath heating at the same temperature. It was indicated that more damages in molds occurred by microwave than water bath, suggesting non-thermal effects existed in the process of microwave sterilization. AFM examination showed that the morphology of A. niger spores’ before and after microwave treatment was quite different. The form of spores was full and the surface was relatively smooth before the microwave treatment, but they shrinked after the microwave treatment. More cellular content overflowed after microwave treatment, which proved that microwave treatment had damage effect on cell membrane of molds.

吉林省科技发展计划项目(20120717);吉林大学基本科研业务费项目（450060487501）;吉林大学本科教学改革研究项目（2013138）