Formation of N-nitrosamines in microwaved versus skillet-fried bacon containing nitrite.

Differences in volatile N-nitrosamines (NNAs) found in nitrite-cured bacon cooked in an electric skillet and a microwave oven were determined. Samples of bacon were fried in an electric skillet at 171 and 206 degrees C and in a standard microwave oven (rated at 700 W full power) for 45 and 75 sec/slice. The level of NNAs were determined in the cooked bacon and fried-out fat by using gas chromatography-thermal energy analysis. Both N-nitrosopyrrolidine (NPYR) and N-nitrosodimethylamine (NDMA) were detected in the fried-out bacon fat at levels up to 20.8 and 23.3 ng/g, respectively. The total NNAs (NDMA and NPYR) in the skillet-fried bacon was c. 11 ng/g for both the 171 and 206 degrees C fried samples. No NNAs were detected in the bacon or fried-out fat after cooking in a microwave oven for 45 sec/slice. However, excessive cooking of the bacon in a microwave oven (75 sec/slice) does produce levels of NPYR up to 5 ng/g. The minimum detectable level of NPYR was 2.08 ng/g and that of NDMA was 0.76 ng/g. These results indicated that the method of cooking meats containing nitrite could affect the level of NNAs in the cooked product, thereby affecting the level of human exposure to NNAs.