N-nitrosodibenzylamine in boneless hams processed in elastic rubber nettings.

Boneless hams processed in elastic rubber nettings contain high levels of nitrosamines in the outermost layer. The precursors of the nitrosamines are zinc dibutyl- or dibenzyldithlocarbamate used as a vulcanizing agent in the formulation of the rubber. The outermost layer from 59 commercial hams was analyzed for 11 volatile nitrosamines including N-nitrosodibutylamine (NDBA) and N-nitrosodibenzylamine (NDBzA). The principal nitrosamine, NDBzA, was detected in 32 (54%) ham samples at the 10-100 ppb range; it exceeded 100 ppb in 18 (30%) samples, with the highest at 512.2 ppb. No nitrosamine was detected in 7 of 59 ham samples. To determine the cause of the high NDBzA values, various types of unused nettings (from different manufacturers) accompanying the samples were analyzed for nitrosamines. No correlation was found between the NDBzA content of the hams and the nettings. The results suggest that the problem of nitrosamine formation in these products has not yet been resolved.

Comparison of three methods for determination of N-nitrosopyrrolidine in fried dry-cured and pump-cured bacon.

Three methods, the mineral oil distillation (MOD), the dry column (DC), and a low temperature vacuum distillation (LTVD), for the determination of N-nitrosopyrrolidine in dry-cured and pump-cured bacon were compared. Each method uses the thermal energy analyzer for the determinative step. The coefficients of variation for repeatability were 10.3% (MOD), 7.2% (DC), and 9.1% (LTVD) for the dry-cured bacon study and 8.7% (MOD), 8.5% (DC), and 7.1% (LTVD) for the pump-cured bacon study. The pooled coefficients of variation for between-method reproducibility were 11.8% for the dry-cured bacon and 10.8% for the pump-cured bacon. The pooled coefficients of variation for repeatability were 9.0% for the dry-cured bacon and 8.2% for the pump-cured bacon. These values compare favorably with the values from previous collaborative or validation studies of the individual methods, and the methods can be considered to be equivalent.