Summary.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 (aw), but for all solutes except glycerol there was a linear relationship between logD65and concentration (% w/w) of solute. Comparison ofD65at a particularawor percentage (w/w) solute concentration showed that the value decreased in the order: sucrose>glucose>sorbitol>fructose>glycerol. In glycerol,D65values 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 theawof the solu