Table 2.

Thermal inactivation kinetics parameters for Listeria monocytogenes strains 568 and 568:ΔTreA at 52°C following growth on different mediaa

Strain and growth medium (trehalose content, mg/liter)βbASEc (β)tcmdASE (tcm)Logistic DL valuee (min)
568
    TSB (70)0.2350.00912.861.7022.57
    TSB-YE (730)0.2280.01012.091.6322.11
    TSB-Tre (10,070)0.2020.01915.623.2626.35
    BHI (310)0.1960.01318.292.2729.95
568:ΔTreA
    TSB (70)0.2030.01011.802.2723.05
    TSB-YE (730)0.176*0.01214.313.1327.14
    TSB-Tre (10,070)0.161*0.00519.21*1.4333.31*
    BHI (310)0.152*0.00429.03*1.1044.09*
  • a The inactivation kinetics was modeled using the modified Fermi distribution function (43). *, significantly different from value for the wild-type 568 for the same treatment (P < 0.05).

  • b β, inactivation rate parameter for the log-linear region of the death curve.

  • c ASE, asymptotic standard error.

  • d tcm, lag parameter prior to the region of maximum inactivation rate.

  • e DL, time for the initial log decline when a lag phase exists (equation 2).