The improved atmosphere within the packages with low o2 concentration, and high concentration of co2 has been shown to significantly long time the shelf life of suitable fish at freezer. Vacuum packing is known to be as one of the methods of extending the shelf life of seafood. The purpose of the present study is to scrutinize the effect of vacuum packaging on oxidative spoilage indexes in fish Lethrinus atkinsoni fillet under freezing at −18°C in 0, 20, and 40 days. To this end, it was initially purchased 20 kg fish from a conventional market in Behbahan, Khuzestan Province, Iran. The total remaining fish after washing and waste removal was divided into packages of 150 g as the required samples and kept in a freezer. The fillets were divided into two groups: The first group was packed in polyethylene bags under vacuum, and the other group was considered as a case of treatment control, kept in freezer at −18°C. The results showed progress spoilage indexes in samples packed in vacuum during 0, 20, and 40 days found lower than control treatment with significant different (p < .05). The peroxide and thiobarbituric acid and free fatty acids contents decreased in frozen samples in 20 and 40 days in vacuum, but pH value increased. The results showed packed samples in freezing and in vacuum conditions, were a suitable method for low lipid oxidation in the L. atkinsoni fillets which led to the samples’ extended shelf life. It is concluded that packaging in vacuum as combined with freezing treatment prevails over freezing in individual by an acceptable long‐term fish shelf preservation.

The Lethrinus lentjan fish is economically and nutritionally important in Iran. Therefore, knowledge of their chemical composition can help in the development of functional foods. In the present study, proximate and fatty acid compositions were determined in fresh and marinated Lethrinus lentjan fish . Fatty acids were identified by gas chromatography. The 24 pieces of fresh L. lentjan fish with an average weight of 470 ± 125 g were prepared. After removing wastes, the fish fillet was placed in a dish containing acetic acid, salt, garlic, and red pepper. The marinade product contained n‐6PUFA (7.94%) and n‐3PUFA (3.46%). The results showed that moisture content in the marinade sample decreased, while fat, protein, and ash contents increased and carbohydrate content was also decreased compared to the raw sample. The marinating process increased PUFA percentage (19.32%) and ratio of PUFA and SFA (0.61). The fresh and processed samples showed superior nutritional quality and the lowest h/H ratio, but AI and TI ratios were relatively favorable ( p < .05). The thrombogenicity index (TI) (0.46) and atherogenicity index (AI) (3.56) were more than the recommended in terms of risk of coronary heart disease. It can be concluded that fresh and processed fish samples represent an excellent source of high‐quality fat, demonstrating that this fish species’ freshwater can be considered optimal for human consumption.

The use of plant material in a diet to increase the growth of fish may be beneficial and can reduce the production cost. This research was carried out at Behbahan University, Iran, in 2016 with a view to determining effects of Beta vulgaris powder on feeding, growth and survival of common carp (Cyprinus carpio). A total of 360 individuals (mean weight, 20 g; mean standard length, 9 cm) were randomly divided into 12 tanks for treatments. Fish were fed diets with 0% (control), 0.5% (T1), 1% (T2) and 2% (T3) of B. vulgaris powder for six weeks. The results showed that the addition of B. vulgaris to fish diets had a positive effect on survival index and feed conversion index of fish. The presence of B. vulgaris in the diet had increased specific growth rate, and hepatosomatic and viscerosomatic indices.

The purpose of this study was to evaluate the nutritional quality and concentration of heavy and toxic metals in the fresh and canned tuna Thunnus tonggol at different storage periods. The content of iron, zinc, copper, mercury, and also macronutrient compounds in the Iranian fresh and canned tuna fish and the effects of thermal processing and subsequent storage on metal contents were evaluated using atomic absorption spectroscopy. The results showed that the levels of iron, zinc, copper, and mercury after the 6th, 9th, and 11th months of storage were 26.52, 10.83, 6.22, and 0.04 mg/kg, respectively. The concentrations of iron, zinc, copper, and mercury in the fresh fish were 11.03, 7.11, 1.71, and 0.03 mg/kg, respectively. The results of the statistical analysis of the samples showed that canning process and sterilization by autoclave increased the contents of elements except mercury to a significant level (p < .05). The results showed that the amount of fat significantly increased in all samples after storage (p < .05), but the ash and protein content significantly decreased (p < .05). The moisture content significantly increased (p < .05) except for the 9th month of storage. The obtained results showed that the energy value after 6 months of storage was the highest (297.53 kcal/100 g). The results showed that the bioaccumulation of copper, iron, zinc, and mercury in the fresh and canned muscles was lower than the standard concentration recommended by the FAO and WHO. This type of fish was a high‐quality food source and it was safe after 11 months of storage and was suitable for human consumption. Therefore, the consumption of Iranian canned tuna can be safe for human health despite the possible contamination with heavy metals.

The fish diet is one of the essential factors in the development of aquaculture. The purpose of present study was to evaluate using grape pomace as a main feed ingredient on growth performance, body chemical composition, survival rate, and morphological indices of the carp (Cyprinus carpio). 200 fish with an average weight of 7 ± 0.4 g were randomly distributed in four tanks for total of 56 days. The fish were fed with a diet containing 5%, 10%, and 15% grape pomace in different feeding groups designated as G1, G2, and G3. The average daily weight gain (g), weights gain (g), and specific growth rate (%) were significantly higher (p < .05) in G3 as compared to G1 and G2 groups. The lowest feed conversion ratio was recorded in G3 group. The morphological indices, condition factors, viscerosomatic index, and hepatosomatic index were significantly higher in G3 group as compared to other treatments. The protein, fat, moisture, and ash contents in the C. carpio fillets were significantly influenced by feeding rate. The results showed that grape pomace had a positive effect on growth, survival, and nutritional indices in the carp fish. According to the obtained results, grape pomace (150 g/kg food) can be considered as the diet component for the carp fish.

The purpose of this study was to evaluate the utilization of Beta vulgaris powder as feed ingredient in the diet of Cyprinus carpio for a period of 56 days. Common carp fry with an average weight of 20 ± 0.2 g were fed using the diet containing B. vulgaris leaves with different concentrations. Fry of Cyprinus carpio were equally distributed in four feeding groups having three replicates each. The study was conducted indoors, in FRP tanks, and aeration was provided to individual rearing units, and it was a flow‐through system. The basal diet was replaced at 0.5%, 1%, and 2% with B. vulgaris powder. The basal diet without B. vulgaris powder (0%) served as control (T1). Significantly higher feed conversion ratio, protein efficiency ratio, and fat and protein indices were recorded in fish fed with B. vulgaris powder in treatments. Different feeding groups showed greater acceptability of B. vulgaris powder mixed diet without any adverse behavioral response. The protein and fat average percentages were 43.32 and 10.79 g, when fish reached commercial weight (48.02, 11.85 g) after 56 days for treatment 2%. After fish feeding with the B. vulgaris, for treatment 2% lower moisture than the control was recorded. The carp fish diet containing 1% B. vulgaris leaf powder caused a significant decrease in the fish fat content. It can be concluded that the diet containing 2% B. vulgaris leaf powder in the common carp led to better growth performance. The presence of B. vulgaris leaves in the fish diet increased the fillet protein and ash content.

The present study aimed to investigate the effect of extracts of turmeric, cinnamon, and lemon on shelf life, macronutrients, and oxidative spoilage of the carp fish in cold storage at 4°C. Fishes were divided into five groups: control (NT); immersed fish in extracts of cinnamon, turmeric, and lemon (CTL); immersed fish in extracts of lemon and turmeric (LT); immersed fish in extracts of cinnamon and turmeric (CT); and immersed fish in extracts of lemon and cinnamon (LC). Results showed immersion of the carp fillet in extracts of turmeric, cinnamon, and lemon improved spoilage indices such as thiobarbituric acid, volatile nitrogen bases, and pH. The used extracts maintained the nutritional value and increased the fish’s shelf life. The compounds existed in the studied extracts decreased the values of the spoilage indices during cold storage. The highest spoilage indices were found for CL and CT treatments, and the lowest was for CTL treatment. The total bacterial load as well as the number of psychrophilic bacteria in the fish fillet found a significant decrease compared to the NT. Therefore, the best treatment was CTL, and inappropriate treatments were CT and CL. The fish shelf life for nine days was extended with the used extracts because the total count of cryophilic bacteria was 0.41 × 104 ± 0.50, which was the lowest compared to other treatments.

Freezing and canning are suitable methods to delay the spoilage of marine products and improve their physico-chemical and organoleptic properties. The fish were transported to the ice in proportion to 1 to 3 (w/w) inside the boxes, and then moved wastes. The purpose of this project is to analyse and to compare the nutritional value of fresh, frozen the fish and canned tuna fish. Nutrient composition and pH of the fresh fish fillet and moisture and ash contents and other nutrient composition were measured by the standard AOAC method. The results showed that the percentage of frozen fish protein was 17.41 and the highest moisture percentage for frozen fish with 72.23. The level of energy (kcal) of canned fish with 393.36 kcal was the highest level. The pH of the canned fish with 7.28 was the highest pH. The percentage of drip and WHC in frozen fillet found 6.7% and 6% respectively. From the obtained results, it can be concluded that despite the low amounts of protein and ash in canned fish, the fat and energy content was the highest. The protein content of the fish is frozen, and its pH indicates that it was better than fresh fish from point of quality.