Aim: To investigate the influence of reducing beef Surface water activity (a(w)) on the survival of Salmonella Typhimurium DT104 during heating. Methods and Results: Beef discs were surface inoculated with S. Typhimurium DT104 and either untreated or dried to achieve surface a(w) values of 0.95, 0.85 and 0.70. The samples were vacuum packed, heat-treated at 60 degrees C and removed at predetermined times. The inactivation curves were influenced by a(w) and treatment time. Biphasic inactivation curves were observed for S. Typhimurium DT104 heat-treated on beef samples with altered a(w) values, which were characterized by an initial decline in cell numbers at commencement of heating followed by a much slower rate of inactivation during the remaining treatment period. Point estimates of the heating time required to achieve a 1 log reduction on beef surfaces with a(w) of 0.99, 0.95, 0.85 and 0.70 were 0.5, 1.55, 11.25 and 17.79 min, respectively. Conclusions: A decrease in beef surface a(w) can Substantially enhance the survival of S. Typhimurium DT104 after heating. Significance and Impact of the Study: Caution needs to be taken using dry air as a decontamination method as this may rapidly decrease product surface and pathogen a(w) values resulting in enhanced survival.