Effects of gamma irradiation on restructured cooked ham formulated with low nitrite content

Abstract

The objective of this study was to analyze the effects of gamma radiation applied at different doses against the survival of inoculated Clostridium sporogenesand Listeria monocytogenes in restructured cooked ham with low sodium nitrite content, as well as on the technological and sensorial characteristics of the products. Higher irradiation doses reduced (P < 0.05) the amount of C. sporogensspores, independent to the addition of sodium nitrite, with a lethality up to 5 log reductions. Gamma irradiation also reduced (P< 0.05) the residual nitrite levels, but had no effect (P > 0.05) on the pH, CIE color parameters or the texture profile, but improved their odour and flavor, according to sensorial analysis. The color of uncured samples was more yellowish (higher hº value) than cured ones, and this difference was perceived by the sensory panel.Irradiation also induced slight protein damage, characterized by the total sulfhydryl groupreduction. However, irradiation did not cause any increase in the cyto or genotoxic (DNA strand breaks) effects in intestinal Caco-2cells. Gamma irradiation had no effect (P> 0.05) on the pH, residual nitrite, synereses, TBARS, water activity or CIE color parameters on sliced ham, although significant (P < 0.05) interactions occurred with sodium nitrite level and storage days on residual nitrite, TBARS, and a*, C* and h° color parameters. The results indicated that irradiation at 6 kGy of cooked ham combined with low levels of nitrite can be used to improve the sensory quality and ensure their microbiological safety against Clostridiumspores and the results indicated that irradiation at 1.5 kGy of RTE ham combined with 50 mg/Kg of sodium nitrite can be used to improve quality and ensure microbiological safety against Listeria mococytogenes