Effect of pistachio (Pistacia vera) hull extract on growth performance,body composition,total phenolic compound and fillets peroxide value of common carp,Cyprinus carpio

This study was carried out to investigate the effect of pistachio green hull extract (PGHE) on growth, survival rates, body composition and oxidative spoilage of common carp fillet. Three hundred fish (11.65 ± 1.65 g) were divided into five dietary treatments with three replications, including 0, 0.5, 1.5, 4.5 and 9 g PGHE kg^?1 of diet. No significant difference were observed in specific growth rate, food conversion rate, weight gain percentage, survival rate and body composition (i.e. moisture, protein, lipid and ash) between different treatments. By increasing the level of PGHE, amount of phenolic compounds in fish meat was elevated whilst peroxide value was reduced. The amount of phenolic compounds in fish fillet was significantly lower (P < 0.05) in control treatment in comparison with other treatments. Peroxide content for 9 g PGHE kg^?1 diet treatment (6.15 ± 0.79 meq peroxide kg^?1 oil) was significantly (P < 0.05) lower than control group (18.82 ± 1.93 meq peroxide kg^?1 oil). Regression analysis of peroxide value indicated that minimum peroxide value obtains in 1187 mg gallic acid kg^?1 diet. This study indicated that ethanolic extract of Pistachia vera hull can be considered as a supplement in fish diet to delay oxidative spoilage of common carp fillet.