Contents of nitrosamine and its precursors in some roasted Nigerian food grains, tubers and animals and their potential ingestion in the diet

摘要

Nitrate, nitrite and N – nitrosamine levels were determined in three varieties of food materials. Nitrate in tubers varied from 60.00 mg/kg in cocoyam (Colocasia esculenta) to 108.00 mg/kg in white yam (Discorea rotunda), while nitrite was from 23.67 mg/kg in cocoyam (Colocasia esculenta) to 80.00 mg/kg in white yam (Discorea rotunda), and nitrosamine was from 0.05 mg/kg in cocoyam (Colocasia esculenta) to 0.12 mg/kg in white yam (Discorea rotunda) varieties. Their levels in grains varied between 38.00 mg/kg in white maize (Zea may) and 82.00 mg/kg in coconut (Cocos nucifera) for nitrate and 10.00 mg/kg and 52.00 mg/kg for nitrite while nitrosamine was from 0.02 mg/kg in yellow maize (Zea may) to 0.05 mg/kg in cashew nut (Anacardium occidentale). Nitrate in meats varied between 47.67 mg/kg in cow meat to 63.33 mg/kg in fish (Tilapia), while nitrosamine was from 0.09 mg/kg in pork to 0.14 mg/kg in fish (Tilapia). On roasting, nitrite and nitrosamine increase in the food samples. Daily intake estimated that the nitrate, nitrite and nitrosamine contents of the food tubers, grains and meats seem to be higher than current acceptable daily intake.