Combined effects of gamma irradiation and silver nano particles packing on the chemical characteristics and sensory properties of saffron, using hurdle technology

ABSTRACT

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. 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. 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]. 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