[Effect of zataria multiflora boiss. essential oil on the growth of listeria monocytogenes in salted fish]

Essential oils and their components have antimicrobial effects. They use with spices as flavoring agents all over the world. They have been used safely since ancient times as herbal medicines. Zataria multiflora Boiss. is one of medicinal herbs in Iran and its antimicrobial effects on foodborne pathogens have to investigate in foodstuff. The aim of this study was to determine of the effect of Zataria multiflora Boiss. Essential oil on the growth of Listeria monocytogenes in salted [4%] silver carp. Effect of different concentrations of this Essential oil [0.0%, 0.045%, 0.135%, 0.405%, and 0.810%] on behavior of Listeria monocytogenes was determined by evaluation of the bacterial growth in salted fish fillets. The essential oil in used concentrations had significant inhibitory effect on the growth of Listeria monocytogenes in salted fish during the storage time. The higher concentration until 0.405%, the more significant inhibitory effects on the growth of Listeria monocytogenes [p<0.05] but 0.405% and 0.810% concentrations had no different significant inhibitory effects on the growth of Listeria monocytogenes [p>0.05]. Organoleptical survey showed that the concentrations of the essential oil used until 0.405% not only had no undesirable effect on flavoring but also it improve taste and flavor of salted fish. The result suggested that the Zataria multiflora Boiss. Essential oil can be considered as a natural preservative in salted fish

Effect of gamma irradiation and frozen storage on microbial, chemical and sensory quality of fish fillet

In this study the effects of gamma irradiation and frozen storage on sensory, chemical and microbial quality of fish fillets was investigated. Hypophtalmyctis molitrix were equally divided to 12 fillets, then these 12 fillets were equally arranged in 4 groups [1-4]. One group considered as control with no treatment and the other 3 groups was treated by 0.75, 3 and 5 KGy of gamma irradiation, respectively. All of the groups were kept in -18?c for 3 month. All of the samples were examined for microbial, chemical and sensory examinations at day zero and 3 months later. The data were analysed by ANOVA [Kruskal-Wallis] using SPSS 10. The results showed treatment with 0.75 KGy of gamma irradiation plus frozen storage in extension of shelf life of fish fillets without any unacceptable effects on sensory and chemical characteristics of them