ABSTRACT
Background: Vibrio paraheamoloyticus is one the causative agents of vibriosis with high mortality in farmed fish and shrimp and under predisposing conditions
Objectives: This study was aimed to assess the effect of gamma irradiation on the inactivation of V. paraheamoloyticus under fresh and freeze-dried conditions
Methods: Vials of 0.5 ml fresh culture of the bacterial suspensions at 1.5[asterisk]10[10] cfu/ml were subjected to 1, 1.5,2, 2.5, 3 and 4 KGy. Also, vials of 0.5 ml freeze-dried culture of the bacterial suspensions at 1.5 x 1010 cfu/ml were subjected to 2, 4, 7 and 8 KGy. The bacterial growth behavior was then evaluated on fresh medium
Results: The obtained results showed that the minimum doses of 4 and 10 KGy were sufficient for the inactivation of fresh and freeze-dried bacteria, respectively
Conclusions: The result of this study shows that inactivation of V. paraheamolyicus in fresh culture condition requires below half- dosage of gamma ray required for the inactivation of the freeze- dried of bacterial cells
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
Subject(s)
Gamma Rays , Nanoparticles , Silver , Crocus/chemistryABSTRACT
[[18]F]KF, considered as a reference standard for positron emission tomography of the skeletal system, was produced by the bombardment of enriched water [[18O]H2O>95%] with high energy protons in NRCAM cyclotron. After the extraction of fluoride from enriched water as KF, and passing it through microbial filter and fine adjustment of acidity and osmolality, it was converted into an injectable form. Pre-clinical investigations and biological controls were performed to determine radioisotope distribution in laboratory rats, thus suitable information was gathered for imaging in humans. This radiopharmaceutical was proved to be quite safe and of high quality as a result of testing in laboratory rats