Effect of Smoking Time and Temperature on the Proximate Composition and Quality of Milkfish Steaks

The effects of additives as a marinade producer on nutritional quality parameters of Oncorhynchus mykiss fish during storage at 4°C

The purpose of the present study was to evaluate the utilization of additive ingredients on the proximate composition, energy value, yield percentage, and pH value of cold and cooked Rainbow trout marinade. In this study, the effect of the marinating solution with different concentrations of lemon juice and salt on various quality properties in the processed muscle was determined. Results showed the pH value of the cold marinade in treatments 2, 3, and 4 decreased to 5.57, 5.15, and 5.14 with significant differences, respectively. The results showed that the marinade yield range (27.1%-19.28%) was found as a result of the marinating process. There was a significant difference between the cold and cooked fish marinades in terms of water content, pH, proximate contents, and yield percentage. The protein content in cold marinade was highest at 16.43%, while in treatments 2, 3, and 4, it decreased to 16.42%, 14.00%, and 14.56%, respectively with a significant difference. The lipid content in cold marinade (2.31%) for treatment 4 was highest, while in treatments 3 and 4, it increased significantly. The cold marinade treatment 4 found the highest energy and nutrient values, while the yield of marinade was 61.21%. The treatment T2 in cooked marinade found the highest energy value and the lowest weight loss (89.7%). Moisture retention in fish-cooked marinade treatments was found to be 13.5%, 5.52%, and 9.77%. It can be concluded that treatment 2 was the best option for both cold and cooked marinades.

Evaluation of fatty acid-related nutritional quality indices in processed and raw (Lethrinus lentjan) fish fillets

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.