Didem Üçok Alakavuk

Survival of Salmonella Enteritidis during salting and drying of horse mackerel (Trachurus trachurus) fillets

Survival of Salmonella Enteritidis inoculated (5-6 log cfu/g) on horse mackerel fillets was studied during salting and/or drying processes at 4 degrees C for up to 70days. Sample groups were as follows: group A (salt/fish=80/100), group B (salt/fish=30/100), group C (salted as group A and dried after 15days), group D (salted as group B and dried after 15days), and group E (dried without salting). The salt content increased in all groups with a maximum level of 29.36%. Final salt contents (%) were higher (P<0.05) in salted-dried groups (C and D) than the salted groups (A and B). Total reductions in a(w) values were found as group E>group D>group C>groups A and B (P<0.05). Salmonella survived 60days in group A, 65days in group B, 35days in group C, 45days in group D and 20days in group E. Drying process following salting accelerated the elimination of this pathogen. Salmonella survived longer in salted samples than in salted-dried and dried samples. This work demonstrated that Salmonella may be inhibited by one of salting, drying and salting-drying techniques; however, processing periods should be long enough to reduce a(w) sufficient to inhibit this pathogen.

Effect of Cooking Methods on Proximate Composition, Fatty Acid Composition, and Cholesterol Content of Atlantic Salmon (Salmo salar)

The effects of different cooking methods (baking, steaming, grilling, and microwaving) on proximate composition, fatty acid composition, and cholesterol contents of salmon were investigated. The moisture, protein, lipid, and ash contents of raw salmon were 61.07 ± 0.63, 20.28 ± 0.06, 17.23 ± 0.73, and 1.23 ± 0.08 (% wet weight), respectively. The proximate composition and energy values of the cooked salmon compared to raw salmon were significantly affected by cooking methods (p < 0.05). Salmon is one of the richest sources of long-chain polyunsaturated fatty acids (PUFA), such as eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA). Cooking methods did not have a significant change (p > 0.05) on fatty acids composition. There was a significant difference (p < 0.05) in cholesterol content of cooked salmon. Essential n-3 PUFAs, namely EPA and DHA, were higher in the grilled and oven baked salmon. Therefore, grilling and oven baking were found to be the best cooking methods concerning omega-3/omega-6 ratio compared to the microwave and steam cooking methods.

The Chemical and Sensory Quality of Smoked Sturgeon (Huso huso): A Case Study

In this study, the tail flesh of sturgeon acquired from the fish market in Beşiktaş-Istanbul, Turkey was put through hot smoking. The chemical composition of raw and smoked sturgeon was determined. The protein, lipid, ash, and moisture of the muscle tissue in raw and smoked sturgeon were found to be 17.63 to 17.49, 6.07 to 9.59, 0.79 to 2.71, and 75.42 to 68.40%, respectively. Both the raw fish and the smoked fish meat were categorized to possess high quality characteristics with pH, total volatile base nitrogen (TVB-N), and trimethylamine nitrogen (TMA-N) values. After smoking, the skin color lightness (L*) of raw fish was determined to decrease, while the flesh color lightness of raw fish was determined to increase. The redness (a*) and the yellowness (b*) of both the skin and the flesh were determined to increase. Sensory parameters of color, smoke aroma, flavor, texture, chewiness, and overall acceptance for smoked sturgeon was described as excellent and its flesh tasty.

Quality Changes of Thermal Pasteurized Mussels (Mytilus galloprovincialis) During Refrigerated Storage at 4±1°C

DOI: 10.26650/ASE2018428669 This study investigated the changes in quality of pasteurized mussels during storage at 4°C±1°C. Mussels (Mytilus galloprovincialis) were harvested from the Marmara Sea in March. The mussel flesh was packed with lemon juice, apple vinegar, finely chopped onion, salt, and black pepper. Then, all the packets were pasteurized (at 70°C for 8 min) and stored for 21 days at 4°C±1°C. Results showed that the contents of protein, fat, and ash of pasteurized mussels were significantly higher (p<0.05) than those of raw samples. The moisture content of mussels was significantly decreased (p<0.05) after heat treatment. The meat yield of pasteurized mussels was 10.42%. Sensory evaluation results indicated that the acceptability of pasteurized mussels at refrigerated storage was limited to 9 days. The TVB-N value of pasteurized samples exceeded the acceptability limit of 22–25 mg/100 g on the 9th day. The TMA-N amount of pasteurized mussels remained lower than the acceptability limit during storage. The initial microbial load of the mussel samples reduced after the pasteurization process. This reduction was observed in the total mesophilic and psychrophilic bacterial count, with the yeast mold counts after pasteurization being 2.44, 2.07, and 2.37 log cfu/g, respectively.