THE EFFECT OF PRIOR HEAT-SHOCK ON THE THERMORESISTANCE OF SALMONELLA-THOMPSON IN FOODS

The resistance of Salmonella thompson to heating at 54° or 60°C in tryptone soya broth, liquid whole egg, 10% or 40%) reconstituted dried milk or minced beef was increased if cells were held at 48°C for 30 min before heating at the higher temperatures. Induction of thermotolerance by mild heat shock is thus not confined to cells grown and heated in broth systems. The heat shock phenomenon may therefore have implications for the safety of foods given marginal heat treatment. © 1987 Oxford University Press. All rights reserved.