Cold pasteurization of rainbow trout fillet (Oncorhynchus mykiss) with gamma rays and shelf life assessment at refrigerated condition

The present study was conducted to evaluate the effect of different doses of gamma rays on shelf life and fatty acids composition of Rainbow trout fillet (Oncorhynchus mykiss) during refrigerating condition. Quality and shelf life of non-irradiated and irradiated (0, 0.75, 1.5, 2.25, 3, 3.75 and 4.5 kGy) Rainbow trout stored at +4 C was investigated by measurement of microbiological, chemical and sensory analysis .Irradiation of fillets was performed by gamma rays from a Co60 source. Microbial counts for non-irradiated trout fillet samples were higher than respective irradiated fish. Total volatile base nitrogen (TVB-N) values was increased from 7 mg/100 g for non-irradiated to 52.7 mg/100 g after 15 days storage at refrigerator, whereas for irradiated fish lower values of 39.4, 37.6, 28.7, 25.6, 24.8 and 23.2 mg/100 g were recorded at 0.75, 1.5, 2.25, 3, 3.75 and 4.5 kGy, respectively (day 15).initial amount of peroxide value in non irradiated sampleswas 0.8 meq/kg and was increased to 7 meq/kg (7 day).Highest amount of peroxide after irradiation process was belonged to samples irradiated by 4.5 kGy (1.5 meq/kg). Also, total viable count of irradiated samples were decreased significantly (p<0.05). On nutritional aspect, results showed that total saturated fatty acid concentrations increased significantly (p<0.001) with increasing irradiation dose , so that the control sample and fish muscles that irradiated with 4.5 kGy had the lowest and highest amounts of total saturated fatty acids (20.454 ± 0.011% and 19.228 ± 0.040% , respectively). The amount of total polyunsaturated fatty acids (PUFAs) in irradiated samples were significantly lower than control sample (p<0.001) and amounts of total monounsaturated (MUFAs) were significantly higher than control samples (p<0.001). The results were indicated that the highest content of MUFAs and PUFAs were in samples irradiated with 3.75kGy (37.783± 0.092 %) and control samples (37.677± 0.104 %), respectively .The lowest level of MUFAs and PUFAs were in control samples (36.596 ± 0.024%) and 4.5 kGy (36.459 ± 0.047%), respectively. Altogether, results of this study were determined that irradiation treatment changes significantly the fatty acid composition especially polyunsaturated fatty acids in rainbow trout muscle (P<0.001). Overall, irradiation of fillet by 3.75 kGy had best results on increasing shelf life of fillet at refrigerator (between 11-15 days) and had no advers effect on fatty acid composition of Rainbo trout fillet

The effect of natural preservative (rosemary and thyme) on minced meat of silver carp

The aim of this study to investigate the antioxidant potential of ethanolic extract of Rosmary(Rosmarinusofficinalis) and Thyme (Zatariamultiflora) on fatty acids stability and shelf life of frozen minced silver carp fish(Hypophtalmictysmolitirix). Treatments include frozen meat in conventional packaging (control), frozen minced fish+200 ppm thyme(treatment 1), frozen meat+200 ppm rosemary (T2), frozen meat + rosemary (100 ppm) and thyme (100 ppm)(T3). Treatments packed in polyethylene bags and were freezed at -36°C by spiral freezer and IQF method, then were transferred to freezer to keep at -36°C during the storage. Treatments were analyzed for 10 days intervals in the First month and 15 days intervals in the second month of storage. In the next few months, treatments were analyzed once a month. In this study, various levels of both saturated and unsaturated fatty acids in the three treatments and control treatment were identified. The results showed that Keeping of Minced Fish containing thyme and rosemary extract in freezing conditions led to stability of fatty acids (MUFA, PUFA, omega- 3 and omega-6) and the changes in fatty acid oxidation during storage is not significantly. The profile of fatty acids and their related indicators results as well as statistical tests showed that treatments containing rosemary extract were more stable (-18°C) in comparison with the control and other treatments during frozen condition. Also these teratmentshad less oleic acid and linoleic acid , ά-linolenic and palmitic acid in compared with others .more According to the results treated minced meat with rosemary extract was kept the quality for six months and more

Study the added value and acceptance of fish patty produced by FPC of Abramis brama

Abrams brama distribution in the Caspian and most of it is in the Anzali lagon. Completed in the rivers to spawn or hibernate done, hibernation mass takes place in the well of the rivers, which feed the crustaceans, mollusks and aquatic insects are born. This fish is almost vertical and is able to search for food in the mud in shallow waters and residents due to competition for food with other species of plankton and plants inevitably feed. This fish has an economic value and good taste for meat consumption has become common. Fish patty prepared food that is easy to cook and good demand. The benefits of fish patty are the most of fresh fish, good use of raw materials, availability of several species of fish in the product, socio-economic benefits for fishermen and fishing industry, product nutritional value and high in protein rejection. Fish Protein Concentrate is a healthy food products, durable and of high nutritional value of fish and hygienic manner in which the protein and other nutrients found in fresh fish and more compact than the long-term maintenance and diverse the second is for the production of food products. The study aimed at producing FPC type A string of fish, fish cakes prepared by the FPC obtained and reviewed the nutritional value, acceptance and endurance cookies generated at room temperature for one month . After examination of the nutritional value, shelf-life tests using factors of corruption, TVB-N, pH, TBArs and sensory tests showed that the most important indicator of the value of food, especially protein product treatments with better FPC and the factors corruption is not much difference between 5% FPC and blank treatment. The final product is important in terms of nutritional value and shelf life, group 2 has a significant difference with other treatments and the final product can be made on the basis of treatment 2