Determination of Freshness and Chemical Compositon of Scad ( Trachurus trachurus, L. 1758) Stored in Refrigerator


Abstract: This study was carried out to determine the freshness and chemical composition of scad stored at +2C - +4°C. As a result of bacterial activities and chemical changes in fish meat TMAO breaks down to TMA, DMA and FA. In the fish meat the amounts of these compounds are important for the determination of the freshness of fish meat. Breakdown of TMAO into DMA and FA has an effect on the properties of the texture of the fish. Hence we attempted to distinguish the textural characteristics of the stored fish with sensorial analysis. It was detected that the results of the sensorial analysis were in parallel with those of chemical analysis. The pH value of fish meat has a very strong effect on connective tissue. With the increase in pH value in fish tissue, enzymes with a bacterial effect become active. The pH value in this study increased as storage time increased in parallel with chemical analysis. After seven days of storage the following average values were recorded; 6.61 pH, 50.4 mg/100g TVB-N, 12.683 mg/100g TMA-N, 3.234 mg/kg FAex. and 4.688 mg/kg FAdest. Except FAdest. and FAex. all the values were determined to be beyond acceptable values. Investigating the chemical composition of fish meat, and determining the processing and storage conditions have a great importance on human nutrition. Fatty fish with weak tissue has limited cold and frozen storage time. For this reason the chemical composition of the species under study was determined. As a result the fish was found to be with medium fat, high in protein with the following values of 1.73 % fat, 1.48 % ash, 72.15 % moisture and 21.02 % protein on average.

Keywords: Scad, trimethylamine, formaldehyde, sensorial analysis.

Full Text: PDF