TABLE 7.

Heat (56°C)-survival-parameter estimates for late-logarithmic-growth-phase (13-h) L. monocytogenes cells previously treated with chlorine

Chlorine concn (mg/liter)	Treatment time (min)	Eqn.a	(1 − f) least heat-sensitive fraction	β2 − least heat-sensitive fraction (min−1)	β1 − most heat-sensitive fraction (min−1)	β (min−1)	Pseudo r2b	Logistic D value (min)c
0	5	3	0.5	0.709 ± 0.056	−0.604 ± 0.144		0.973	4.15
0	10	3	0.5	0.738 ± 0.047	−0.555 ± 0.121		0.983	3.98
2.0	5	1				0.593 ± 0.014	0.994	4.96
2.0	10	1				0.678 ± 0.011	0.997	4.34
2.4	5	2	0.2	0.512 ± 0.024	0.809 ± 0.160		0.990	5.74
2.4	10	1				0.962 ± 0.040	0.985	3.06
6.0	5	2	0.1	0.413 ± 0.053	2.090 ± 0.651		0.950	7.12
6.0	10	2	0.1	0.424 ± 0.008	3.950 ± 0.314		0.999	6.93

^aParameter estimates were obtained by fitting survival data to the appropriate logistic equation (Eqn.) by nonlinear regression. 

^bCalculated as 1 − (residual sum of squares/corrected total). 

^cCalculated as D = 2.94/β for equation 1 or D = (ln19)/β₂ for equations 2 and 3.