Ga. Mitchell et al., THE EFFECT OF TRANSIENT TEMPERATURES ON THE GROWTH OF SALMONELLA-TYPHIMURIUM LT2 .1. CYCLING WITHIN THE GROWTH REGION, Journal of Applied Bacteriology, 77(1), 1994, pp. 113-119
The effect of fluctuating temperatures on microbial growth is importan
t in the passage of foods through the food chain. Suspensions of Salmo
nella typhimurium were subjected to sinusoidally time-varying temperat
ures of periods from 40 to 480 min within their growth temperature ran
ge. The change in the numbers of viable bacteria was measured with tim
e and the experimental growth curves and average generation times comp
ared with predictions based on isothermal growth data. The experimenta
l average generation times exceeded the predictions by less than 30%,
although the discrepancy increased with cycle frequency. Instantaneous
growth rates obtained for the 480 min cycles were in agreement with t
hose predicted from isothermal behaviour.