The effect of diet containing garlic powder (Allium sativum) on mercury bioaccumulation and shelf life of common carp fillet (Cyprinus carpio)

The present study aimed to assess the impact of a diet containing garlic powder on the absorption of mercury chloride in common carp (Cyprinus carpio) fillets and its shelf life in the refrigerator. For this purpose, fish were fed diets containing 2% garlic powder, 10 mg/kg mercury chloride, and 2% garlic powder + 10 mg/kg mercury chloride for 56 days. At the end of the cultivation period, growth index (weight gain, feed conversion ratio, and specific growth rate) and mercury accumulation in fillets were measured. In addition, chemical (thiobarbituric acid reactive substances index) and microbial (total mesophilic bacteria, total psychrophilic bacteria) indices were assessed in the fillets during storage in the refrigerator (4˚C). The results showed that weight gain (0.15±0.06), and specific growth rate (0.88±0.04) of fish-fed mercury chloride decreased, while the feed conversion ratio (4.01±0.01) increased (P<0.05). The highest mercury accumulation was observed in the fillets of fish-fed mercury chloride (506.12±19.67 ng/g) and the lowest in the fillets of fish-fed mercury chloride along with garlic powder (255.30±26.13 ng/g) (P<0.05). Different dietary regimes did not have a significant effect on the chemical and microbial indices of fillets stored in the refrigerator (P>0.05). The results of the present study showed that the use of garlic powder in the diet was an effective method of reducing mercury accumulation in common carp fillets. However, since it did not have a significant effect (P<0.05) on the shelf life of fillets (6 days), using this method is not recommended for increasing the shelf life of common carp fillets.