en Radiation Biology Radiation Biology گزارش کوتاه Short Report <span style="font-weight: bold">Background:</span> Saffron, the dried stigmas of crocus sativus, is the world's most expensive spice which has been used as food additive and flavoring agent. The aim of the present study has been to investigate the combination effects of gamma irradiation and silver nano particles packing on the chemical properties of saffron during storage time. A combination of hurdles can ensure stability and microbial safety of foods. <span style="font-weight: bold">Materials and Methods:</span> To investigate the combination effects, saffron samples were packed by Poly Ethylene films which were possed up to 300 ppm nano silver particles as antimicrobial agents and then irradiated in cobalt – 60 irradiator (gamma cell Model: PX30, dose rate 0.55 Gy/sec ) to 0, 1, 2 ,3 and 4 kGy at room temperature. UVspectrophotometer was used to quantify the most important components crocin, picrocrocin and safranal which were respectively responsible for color, taste and odor. <span style="font-weight: bold">Results: </span>Statistical analysis showed that irradiation and silver nano particles films packing could increase the flavor and aroma of saffron, and the best optimum dose of irradiation was 2 kGy. Also, sensory evaluation showed no significant difference between them (P<0.05). <span style="font-weight: bold">Conclusion:</span> Hurdle technology has been more effective than irradiation or nano-silver particles packing methods. Therefore combined method can be used for microbial decontamination of saffron with no significant differences on chemical characteristics and sensory attributes. <span style="font-weight: bold">Iran. J. Radiat. Res., 2012 9(4): 265-270</span> Saffron, gamma irradiation, silver nano particles, crosin, picrocrocin, safranal 265 270 http://ijrr.com/browse.php?a_code=A-10-1-412&slc_lang=en&sid=1 E. Hamid Sales 790031947532846002475 790031947532846002475 No S. Rajabifar srajabifar@nrcam.org 790031947532846002476 790031947532846002476 Yes F. Motamedi Sedeh 790031947532846002477 790031947532846002477 No