Meat and skin color changes in Rainbow trout (Onchorhyncus mykiss) by feeding safflower (Carthamus tinctorius)

This study aimed to evaluate the effects of safflower on skin color and rainbow trout carcasses were implemented. For this purpose was researched a total of 240 fishes ranged in weight from 230±10 gr as a completely randomized design with 4 treatments, 3 replicates and 20 pieces per replicate for 45 days in Khojier station research on June to August 2013. Diets were included a control group, five, ten and fifteen percent of safflower. To perform for colorimetric tests of rainbow trout skin and meat 2 fishes at day 45 randomly caught and a piece of the meat with skin was removed and after 24 hours of freezing, L*(brightness), a*(redness) and b*(yellowness) parameters were evaluated by Minolta CR-400 colorimetric device. In the Colorimetric Results showed that between dorsal muscle parameters L *, a * and b * treatments on compared to control were non-significant difference) P>0/05). The skin colorimetric showed brightness indicator a significant difference in 10% of safflower treatment compared with other treatments (P≤0/05). In conjunction with redness and yellowness indices, treated with 15% safflower showed non-significant increase and decrease, respectively, compared to the control group (P>0/05). This experiment showed that the use of different levels of safflower can be effective in changing the skin color of the rainbow trout.