Effects of Scrophularia striata water extract on quality and shelf life of rainbow trout [oncorhynchus mykiss] fillets during superchilled storage

The purpose of this study was to evaluate the effects of Scrophularia striata water extract on the quality and shelf life of the rainbow trout fillet during superchilled storage. Fish samples were treated with 1% and 3% S. striata water extract and then stored at -2[degree]C for 20 days. The samples were analyzed periodically for chemical, microbial and sensory characteristics. Results indicated that incorporation of S. striata water extract on rainbow fillets caused the delay of lipid peroxidation and hydrolytic spoilage in 3% treated sample in comparison with the control sample at the last day of the experiment [P<0.05]. Moreover, fish fillets containing 3% S. striata water extract showed lower bacterial count than the control and 1% water extract supplemented samples [P<0.05] during the experiment. According to sensory analysis results, 3% treated samples were acceptable even at the end of the 20-day storage. It was concluded that the effect of S. striata extract on fish samples was to retain their good quality characteristics and extend the shelf life during superchilled storage

[Effect of zataria multiflora boiss. essential oil on enterotoxin production by staphylococcus aureus ATCC 6538]

Staphylococcal food poisoning does not result from the ingestion of S. aureus per se, but rather from enterotoxins which are pre-formed within the food. There is no report on effect of Zataria multiflora Boiss. essential oil on enterotoxin production by this microorganism. The aim of this study was to evaluate the effect of different concentrations of Zataria multiflora Boiss. essential oil on enterotoxin production by S. aureus. This study was done as a factorial model using different concentrations of EO [0, 0.005, 0.015 and 0.03%].The bacterial growth was evaluated during 43 days of incubation and enterotoxin production was analyzed using a enterotoxin assay kit. The growth of the organism was completely inhibited by the EO=0.03%. Enterotoxin production was not affected by sub-inhibitory concentration of EO at level of 0.005%, while it was significantly [p < 0.05] inhibited by increasing subinhibitory concentration of EO to 0.015%. The adverse effect of sub-inhibitory concentration of Zataria multiflora Boiss. EO on enterotoxin production by S. aureus, demonstrated in this study, suggests the potential application of this EO as a natural antimicrobial in foods