Thermal inactivation of Listeria monocytogenes in the Shaka agitated reciprocal retort: Influence of food matrix rheology and fat content

The effect of food matrix rheology and fat content on thermal inactivation Listeria monocytogenes in the Shaka agitated retort (final temperatures 59, 64, 69 °C) was investigated using four fish-based artificial model systems: low-viscosity liquid (liquid), high-viscosity (xanthan), emulsions containing 10% 20% (emulsion emulsion 20%). Model system rheology, quantified by consistency index K flow behaviour n, influenced load to which systems were exposed during treatments. Thermal loads followed order ≥ xanthan, a trend also valid for sublethal injury induced cells. Log reductions xanthan 20%, indicating protective an increased content, not related heat transfer differences. Between approximately 59 62 °C, temperature range over largest portion achieved, maximum specific rate kmax same as log reductions. Overall, efficacy could be linked dynamics, while more complex.