Determination of Nitrate and Nitrite Residues in Smoked Caspian Kutum, Rutilus frisii kutum and Mullet, Liza auratus in the North of Iran

High dietary nitrate and nitrite intake may increase the risk of gastro-intestinal cancers due to the In vivo formation of carcinogenic chemicals known as N-nitroso compounds. In this study nitrate and nitrite residues in smoked Caspian kutum, Rutilus frisii kutum and mullet, liza auratus in the local markets (considered as batch no. 1, 2 and 3) of north of Iran were determined using Spectrophotometer-UV. In smoked Caspian kutum, nitrate content ranged from 12.3 to 19.5 mg/kg and nitrite was between 0 and 12.8 mg/kg. In this species batch No. 2 had the lowest levels of nitrite (2.2±0.3 mg/kg) compared to batch 1 and 3 (P<0.05) while nitrate values were approximately the same for three batches. The highest amount of nitrite was observed in batch number one of smoked mullets while in batch number 2 and 3 nitrite levels were lower than 1.9 mg/kg. Nitrate contents were between 9.8 and 25.2 mg/kg with batch No. 2 showed lower values (P<0.05) than the other samples. In conclusion, the present result has shown that smoked fish available in local markets present a wide range of nitrite and nitrate contents which is some samples was above the threshold tolerance that can be of risk concern for consumption.