Impact of environmental water activity on E. faecium thermoresistance and possibility of regeneration of heat-damaged cells in pasteurised canned meat.

摘要

Production of high-quality tinned meat requires optimisation of sterilisation and pasteurisation processes. Changes in conditions during heating (aw , pH) affect thermoresistance of microorganisms and the possibility of their regeneration following the heating process. Inactivation models of microorganisms used in practice do not take into account these factors. The aim of this study was to determine the influence of the decreasing water activity of the medium during heating and recovery on the thermoresistance of Enterococcusfaecium and determine zaw (the distance of a_w from awopt = 1 which leads to a tenfold reduction in D value) and z'_aw (the distance of aw from a'_w of the recovery medium which leads to a tenfold reduction in D value) parameters. The performed experiments revealed that Enterococcusfaecium PCM 1859 thermoresistance increased during heating in the environment characterised by reduced aw . Statistically significant differences occurred when aw was reduced to the value of <0.97. The impact of aw on the Enterococcusfaecium PCM 1859 thermoresistance was characterised by the following coefficients: zaw = 0.14-0.28, zaw = 0.18-0.44