Gülgün F. Ünal Şengör

Quantification of gaping, bruising, and blood spots in salmon fillets using image analysis.

UNLABELLED An image analysis method was developed to quantify the gaping, bruising, and blood spots of red salmon (Oncorhynchus nerka) fillets. Images of 15 fillets with various levels of gaping were taken either with a dSLR camera, or with a video camera. Also, the same fillets were recorded using the same camera both under regular illumination, and under polarized illumination. In either case, light at an angle was used to highlight the gapes in the flesh. An image analysis method was developed that can adaptively apply an L*threshold value to the image depending on the average color of the fillet, and quantify the resulting percent of the fillet area that has an L* value less than or equal to L*threshold. Polarized lighting changed the color by eliminating artifacts resulting from reflections. It is recommended to use polarized light for this purpose. Both cameras could be used adequately to quantify defects. The proper setting of the L*threshold value depended on the camera and on the polarized light. No correlation could be found between the average L* value of the fillets and the L*threshold value. It was possible to quantify the gaping, bruising, and blood spots on the salmon fillets using this method, which can be the first step toward the automation of this operation. PRACTICAL APPLICATION   Gaping, bruising, and blood spots can be recognized and quantified by analyzing images of salmon fillets. Polarized light is recommended to eliminate color artifacts caused by reflected light. This can be used to automate the detection of these defects.

The Effect of Ascorbic Acid, Citric Acid and Salt on the Quality of Spiny Dogfish (Squalus acanthias) Fillet

ABSTRACT In this study, spiny dogfish fillets were soaked in 10% brine (1:2 w fillet/v solution) for 30 min. Then they were dipped in a solution containing 0.1% ascorbic acid and 1.0% citric acid (1:2 w/v) for 5 min. All samples were covered with ice and stored at 3 ± 1°C for 12 days. Sensory, chemical, and bacteriological analyses were done in every 3 days. Sensory values were 3 and 5; pH values were 7.03 and 6.87; mesophilic aerobic bacteria counts were 5.77 and 5.56 for the control and treated samples, respectively, at the 12th day and these values were significantly (p < 0.05) different. Control samples were marketable on the 9th day and spoiled on the 12th day of storage while the treated samples were still marketable. It was seen that treatment of the spiny dogfish fillet with salt, ascorbic acid, citric acid increased the shelf life.

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.

SOUS VİDE TEKNOLOJİSİ İLE MUAMELE EDİLEN BALIKLARIN KALİTE PARAMETRELERİNİN İNCELENMESİ

Sous vide teknolojisi su urunlerindeki doymamis yag asitleri ve vitaminlerin gidada alikonmasina imkan veren bir yontemdir. Su urunlerinde bozulmaya sebep olan patojen bakteri miktari onemli saglik ve finansal etkilere sebep olabilmektedir. Patojen bakterilerin oldurulmesi ya da buyume oranlarinin degistirilmesi icin gidanin nasil pisirilmesi gerektiginin bilinmesi onemlidir. Bu sebeple gidalar dusuk sicakliklarda pastorize edilerek guvenli hale getirilebilmektedir. Vakum paketlerde stabil isida pisirme su urunlerinin raf omrunu uzatarak tat ve besin degerini koruyabilmektedir. Sous vide teknolojisi ile pisirilmis baliklarin raf omurleri firinda pisirme, buharda pisirme gibi geleneksel yontemlerle pisirilmis baliklarin raf omrune gore daha uzundur. Ote yandan farkli muhafaza yontemleri, bitki ya da baharatlarla islem sonrasi kontaminasyon riski olmaksizin kombine edilebilmektedir. Sous vide teknigi ile pisirilmis balik, diger geleneksel pisirme yontemleriyle pisirilen baliga gore daha iyi mikrobiyolojik (toplam mezofilik bakteri sayisinin kontrolu gibi), kimyasal (toplam volatil baz nitrojen degerinin kontrolu gibi), fizikokimyasal (renk, tekstur, su aktivitesi, pH kontrolu gibi) ve duyusal kaliteye sahip olabilmektedir.