| Spices make food taste more delicious, and also have function of enhanceing appetite, promoting digestion and absorption for human body. Spices are widely used in pharmaceutical and cosmetic industries with the increasing research on physiological substances, and their world's import and export volume increased yearly. But excessive microorganism level of finished or semi-finished products was one of the main problems of during spices processing. Therefore, applying irradiation sterilization techniques to spices is great important to keep our food safety.The pollution of cumin powder, Chinese prickly powder, chili powder, fennel powder and ginger powder were investigated. Results showed that all spices except ginger were polluted seriously by coliforms with average value of 4.11×106 MPN/100g. With the increase of radiation dose, the content of microorganisms reduced significantly. The death rate of bacteria and bacillus were 70%～90% and 40%～60% at 1.84kGy radiation dose, indicating significant sterilization effects on spices. Coliforms was sensitive to irradiation, its D 10 va1ue was 2.05～3.21kGy and was the indicating bacteria of radiation dose set. Recommended dose of radiation were 14.98kGy, 9.34kGy, 12.10kGy and 15.08kGy. Coliforms was not detected in ginger, and the total number of bacteria was indicating bacteria and its D 10 value was 2.49kGy.Results also showed that water activity and packaging were not significantly affected the sterilization under the conditions. The bacteria population decreased signifcanlty after 2 days of irradiation, and then began to increase and reached a peak at 7 days. But with the extension of storage time, microbiological numbers of irradiation samples reduced significantly, which proves obvious subsequence domino effect. Considering the effectiveness and cost of storage, PE and composite kraft paper might be the best packaging.Radiation-resistance bacteria were isolated, purified and identificated as Bacillus cereus. The separate strain had strong resistant to radiation especially No.3 bacteria, which D 10 values were significantly different in the saline, nutrient broth and cumin. D 10 values in cumin powder was 2.56～3.56kGy. Combining microwave and irradiation may enhance sterilization efficacy for spices.Irradiation dose of spices could be determined rapidly and accurately by using of control charts to monitor the initial bacteria pollution of spices. The introduction of HACCP system during spices processing could improve quality and hygiene of final product.The effects of irradiation on the antioxidant properties of the cumin were investigated by using the radical-scavenging effects on the 1,1-diphenyl-2- picrylhydrazyl (DPPH) radicals. The contents of tannin of irradiation samples were significantly decreased with the increased dose. The recommended does did not affect significantly the total polyphenols or flavonol contents and the DPPH radical-scavenging activity of the ethanol extraction or essential oils.38 kinds of essential oil compounds were detected by GC-MS, Cuminal(53.26%) and Cumin alcohol(14.49%) were the main components in volatile compounds of cumin. There was no significant difference in content of Cuminal, while the content Cumin alcohol significantly reduced by 99.03% at 25kGy. Irradiation dose had no significant impacts on color of cumin and the variety of terpenes. Therefore, recommended dose did not affect significantly the quality of spices.
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