Comparison of Flesh Colour Assessment Methods for Wild Brown Trout (Salmo trutta macrostigma), Farmed Rainbow Trout (Oncorhynchus mykiss) and Farmed Atlantic Salmon (Salmo salar)

Abstract

Red/pink flesh colour is the most distinctive visual quality characteristic in wild brown trout (WBT), farmed Atlantic salmon (FAS) and farmed Rainbow trout (FRT). The study was conducted on three fish species to investigate the relationship between total carotenoid concentration (TCC) and flesh colour, determined by visual and colorimetric methods, of three fish species. Linear relationships were observed between CIELAB colour measurements (lightness-L*, redness-a*, yellowness-b*, hue-H°ab and chroma-Cab), DSM SalmoFan card scores and TCCs. The redness (a*) was mostly correlated with TCC of the fish fillets. The FRT group had the highest TCC (9,75 mg kg-1) compared to the other two species. However, DSM SalmoFanTM card score was higher in FAS group (28,98) than that measured in FRT and WBT. The TCC of trout flesh linearly increased with increasing the a* and decreasing the L* values. The marketing of FRT produced in Turkey has difficult in the world due to the pale flesh colour demand of the consumers. This study showed that SalmoFan CardTM scores could be practical and reliable tool for Salmonid farms as compared to other methods.