Mutagenicities of 22 Kinds of Foods After Nitrite Treatment

The mutagenicities of 22 kinds of foods,including soy sauce,fish sauce,shrimp paste,sausages,sundried fishes,rice cracker,deep fried pork skin,salted vegetable and spices after nitrite treatment,were detected by meansof Ames test with preincubation.Mutagenicity assay was employed on Sal-monella typhimurium TA100,and meanwhile,the validity of each experi-ment was checked by using the known mutagen,AF-2,as the positivecontrol.16 kinds of foods showed marked direct-acting mutagenicity towardSalmonella typhimurium TA100 after nitrite treatment.Shrimp paste prod-uced in Bankok was the strongest one among these samples.Its specificmutagenicity was 37000 revertants/g.The amount of precursor,tyramine,in shrimp paste was estimated fromthe area of tyramine peak on HPLC by using the authentic tyramine as thestandard.Results showed that one gram shrimp paste contained 439μgtyramine.The mutagenicities of foods suggested that nitrosatable precursors,suchas amine or amide,were present in foods,and they could be converted intoendogenous carcinogen,nitrosamine,in vivo.Therefore,detection of muta-genicities of foods has significance in preventing cancer.

Mutagenicities of 22 Kinds of Foods After Nitrite Treatment