Effects of dried, powdered carrot (Daucus carota) incorporated diet on the skin and flesh colouration of Catla catla

Abstract

Dull yellow coloured flesh of C. catla is less attractive to the consumer. Present study investigated the effects of dried, powdered carrot incorporated feed as a source of carotenoids on pigmentation and sensory properties of C. catla skin and flesh. Two groups of C. catla fingerlings (4.39±0.13 cm and 2.41±0.13 g) were fed with a commercially available feed (CF) incorporated with 100 mg/kg dried and ground D. carota, sieved using 250 μm (CF+C1) and 450 μm (CF+C2) mesh and it was compared with a control group of fish of the same size fed with CF. Each group included three replicates of 10 fish. Fish were fed ad libitum thrice daily for 10 weeks. Total carotenoid content in flesh and skin, average daily gain (% ADG), specific growth rate (% SGR), feed conversion ratio (FCR), hepato-somatic index (HSI), daily feed consumption (g/day/tank) and survival rate of fish were analysed at the end of the experiment. A sensory evaluation of fish flesh was done by a panel of judges. It was revealed that D. carota incorporated feed CF+C1, CF+C2 provided a significantly higher carotenoid accumulation by wet weight in flesh (1.36±0.11 and 1.19±0.09 μg/g, respectively) and in skin (2.79±0.08 and 2.82±0.06 μg/g, respectively), compared to flesh (0.45±0.04 μg/g) and skin (0.72±0.14 μg/g) of the CF fed fish. There were no significant differences (p>0.05) among the two experimented groups in the average weight, % SGR, daily feed consumption and % ADG at the end of experiment. Significantly lower FCR was observed in CF+C1 and CF+C2 fed fish (3.90±0.27, 3.98±0.68, respectively) when compared to fish fed with CF (4.91±0.39). Sensory analysis revealed that the flesh of fish fed with D. carota predicate a bright pink colour and was preferred, compared to the flesh of control group.