高能电子束辐照对大米中微生物的杀灭效果

采用单因素试验和正交试验方法，以辐照剂量、辐照时间、物料厚度为变量，研究高能电子束辐照对大米中微生物的影响，探明高能电子束辐照对大米中主要微生物产生明显作用效果的最佳作用条件。结果表明，不同辐照条件对大米中菌落总数、霉菌和酵母菌以及大肠杆菌杀菌效果不同。随着辐照剂量的增大，对大米中微生物杀菌效果越好。正交试验优化得出高能电子束辐照最佳条件为：辐照剂量4 kGy、辐照时间6 s、辐照物料厚度10.5 cm。此条件下，测得大米中菌落总数为82 CFU/g，霉菌和酵母菌总数为2 CFU/g，大肠菌群未检出，高能电子束辐射对大米中微生物杀灭率均超过99%。

Killing Effect of High Energy Electron Beam Irradiation on Main Microorganisms in Rice

The killing effect of high energy electron beam (HEEB) irradiation on main microorganisms in rice as a
function of irradiation dose, irradiation time and material thickness was examined using single factor and orthogonal array
experiments, aiming to find the optimal conditions for microbial inactivation of rice. Results showed that the efficacy of
HEEB irradiation against the total number of colonies, total combined molds and yeasts count (TYMC) and E. coli. varied
with the treatment conditions, showing a positive correlation with irradiation dose. The optimum conditions for HEEB
irradiation were determined as follows: irradiation dose, 4 kGy; irradiation time, 6 s; and material thickness, 10.5 cm. Under
these conditions, the total number of colonies in rice was 82 CFU/g, the total number of mold and yeast colonies was 2 CFU/g,
and E. coli was not detected. Thus, the microbial inactivation efficiency of HEEB irradiation for rice was more than 99%.