Color of raw, frozen, and smoked fillets of rainbow trout (Oncorhynchus mykiss) fed diets supplemented with astaxanthin and saponified red chilli (Capsicum annuum) extracts

Rainbow trout (Oncorhynchus mykiss) were fed diets supplemented with astaxanthin and saponified red chilli extracts. Raw fillets resulted in a decrease of lightness (L*), hue (h*) and chroma (C*) values, and in an increase of redness (a*) and yellowness (b*) values as diet feeding time increased. Frozen fillets showed a decrease in L* and h* values and an increase in a*-, b*, and C* values, and exhibited differences of color (Delta E*) between 2.4 to 11.0 units depending on freezing time, when trout were fed diets containing 200 g-kg(-1) (SC200) and 250 g . kg(-1) (SC250) of saponified red chilli extracts compared with that obtained from feeding the trout a diet containing 100 g-kg(-1), (CP) astaxanthin. During the smoking process, L* and a* values were not significantly different (p >= 0.05), and b*, h*, and C* values increased significantly (p < 0.05) with all the experimental diets. The astaxanthin containing diet produced fillets with a more reddish-pink color than the rest of the experimental diets.