The Effect of Sugars and Polyols on the Heat Resistance of Salmonellae

S ummary . The heat resistance at 65° of 3 strains of salmonellae in solutions of sugars or polyols was enhanced as the concentration of the solutes increased. There was no linear relationship between heat resistance and water activity ( a w ), but for all solutes except glycerol there was a linear relationship between log D 65 and concentration (% w/w) of solute. Comparison of D 65 at a particular a w or percentage (w/w) solute concentration showed that the value decreased in the order: sucrose > glucose > sorbitol > fructose > glycerol. In glycerol, D 65 values were always very much lower than in any other solute. With sucrose–glycerol or sucrose–glucose mixtures, heat resistance depended both on the total concentration (% w/w) of solutes present and also on the a w of the solution.