Effect of astaxanthin and garlic essential oil in the diet of rainbow trout and evaluation of biometric indicators, antioxidant and organoleptic properties of the meat

This study aimed to evaluate the effects of additive garlic essence and astaxanthin in macrostructural and nanostructural forms in rainbow trouts’ feed on preservative and sensory properties of meat and biometric measures. Garlic essential oil was produced by Clevenger apparatus and nanostructural forms were prepared by emulsifier and by mixing organic and aqueous phases. Seven hundred fish were equally and randomly divided into seven groups in separate pools with a control group. Six treatments were considered as follows: macrostructural garlic essence (T1), macrostructural astaxanthin (T2), nanostructural garlic essence (T3), nanostructural astaxanthin (T4), garlic essence with astaxanthin in macrostructural (T5) and nanostructural (T6) forms in diet. After 40 days, meat samples were evaluated for antioxidant and sensory properties. Biometric measurements were performed during the farming. Results showed a notable reduction of peroxide and thiobarbituric acid values and positive effects on the smell, flavor, and color of the treated groups’ meat compared to the control group (p<0.05). The meat texture was adversely affected in T1 (p<0.05); However, other treatments showed no effects on meat texture (p>0.05). The mortality rate was lower in the treated groups and the lowest FCRs (Feed Conversion Ratio) were observed in T3 and T4 groups. In general, it was discovered that garlic essence and astaxanthin in the diets improved antioxidant and sensory properties of meat and the biometric properties of rainbow trouts.