Nrisinha P. Sen’s research while affiliated with Health Canada and other places

The effect of inclusion of mechanically separated seal meat (MSSM) and seal protein hydrolyzate (SPH) on the formation of N-nitrosamines in chicken salami was investigated. Inclusion of MSSM (10 or 20%) or SPH (1 or 2%) in salami had little effect on the formation of N-nitrosodimethylamine (NDMA) in the products. While the control sample contained 0.33 μg/kg NDMA, other samples contained 0.37 to 0.52 μg/kg of NDMA. Smoking of the samples resulted in small but an insignificant difference in the content of NDMA in the products. Some products contained traces of N-nitrosopiperidine, N-nitrosopyrrolidine and N-nitrosomorpholine, which were perhaps formed from interaction of amines in spice mixes with nitrite. Boiling, microwaving and frying had little effect on the content of N-nitrosamines; fried products contained up to 0.79 μg/kg NDMA.

Nitrite-free cured pork systems were prepared using the preformed cooked cured-meat pigment (CCMP) and sodium ascorbate. Absence of volatile N-nitrosamines in cooked nitrite-free systems was confirmed using a gas chromatography-thermal energy analyzer (GC-TEA) methodology. Similar results were obtained when cod, cod surimi or mixtures containing pork with 15 or 50% cod or cod surimi were used. However, counterpart samples cured with sodium nitrite (156 ppm) and sodium ascorbate (550 ppm) produced N-nitrosodimethylamine at 1·0 ppb levels or less. Results demonstrate that nitrite-free curing of meat and meat/fish systems containing the preformed CCMP is successful in yielding products devoid of volatile N-nitrosamines.

The effect of curing agents, nitrite and ascorbate, on the content of hemoproteins, their nitroso derivatives, color development, and possibility of N-nitrosamine formation in mechanically separated seal meat (MSSM) and seal surimi was investigated. Treatment of MSSM and washed MSSM with up to 200 ppm of sodium nitrite in the presence of 550 ppm of sodium ascorbate resulted in pigment conversions of 68.50 and 66.17 %, respectively. The Hunter a (redness) values of cured MSSM as such, MSSM after one aqueous washing, or MSSM washed first with water and then with 0.5 % NaCl were well correlated with the content of nitrosylheme in the meat (correlation coefficients: 0.952, 0.896, and 0.899, respectively). Although seal meat contains low amounts of trimethylamine, dimethylamine, spermidine, and spermine (0.73, 0.42, 0.30, and 2.98 mg %, respectively), no volatile N-nitrosamines were detected in the samples treated with sodium nitrite and sodium ascorbate at concentrations recommended by U.S. Department of Agriculture regulations.