Different applications in the evaluation of Turkish salmon (Oncorhynchus mykiss) in fishery products processing industry

Deterioration in fish, which is the most valuable example of animal protein source, occurs due to microbiological, enzymatic and chemical reactions after hunting and harvesting. In this study, the effects of not draining rainbow trout (Oncorhynchus mykiss Walbaum 1792) blood during harvesting on fish quality were investigated. In this context, the shelf life was determined by examining the changes in quality values during storage at 4±2°C after the head and internal organs of the bled (KA) and unblooded (K) rainbow trout were obtained. During the nine (9) days of fresh storage, the samples were given nutritional (crude ash, dry matter, crude oil, crude protein), physicochemical (pH and water activity, Quality monitoring was performed with total volatile basic nitrogen and thiobarbituric acid), sensory (color, odor, appearance and general acceptability) and microbiological (total aerobic mesophilic bacteria (TMAB), total psychrophilic bacteria (TPAB), total coliform) analyzes. On the 0th day of storage, the TVB-N value was 14.78±0.07 and 11.97±0.07 mg/100 g in the KA and K groups, respectively. This value was determined as 26.05±0.07 mg/100 g in the KA group on the 9th day, while a value of 30.98±0.14 mg/100 g was found for the K group and exceeded the limit value. In both groups, pH value decreased on day 9 compared to day 0, and this value was determined as 5.88 for the CA group and 6.03 for the K group on the last day. When TBA values were examined, no positive effect of bloodletting on the quality was observed at the end of the storage period. As a result of the sensory evaluations made by the panelists, no clear distinction was made between the bled group and the not-blooded group. As a result of the physicochemical, sensory and microbiological analyzes performed within the scope of the parameters affecting the quality, no significant difference was observed between the two groups. With this study, it has been predicted that the shedding of blood in the harvesting process may depend on the operator's preference.