Thermal inactivation kinetics of human norovirus surrogates and hepatitis A virus in turkey deli meat

Abstract

Human noroviruses (HNoV) and hepatitis A virus (HAV) have been implicated in outbreaks linked to the consumption of presliced ready-to-eat deli meats. The objectives of this research were to determine the thermal inactivation kinetics of HNoV surrogates (murine norovirus 1 [MNV-1] and feline calicivirus strain F9 [FCV-F9]) and HAV in turkey deli meat, compare firstorder and Weibull models to describe the data, and calculate Arrhenius activation energy values for each model. The D (decimal reduction time) values in the temperature range of 50 to 72°C calculated from the first-order model were 0.1±0.0 to 9.9±3.9 min for FCV-F9, 0.2±0.0 to 21.0±0.8 min for MNV-1, and 1.0±0.1 to 42.0±5.6 min for HAV. Using the Weibull model, the tD = 1 (time to destroy 1 log) values for FCV-F9, MNV-1, and HAV at the same temperatures ranged from 0.1±0.0 to 11.9±5.1 min, from 0.3±0.1 to 17.8±1.8 min, and from 0.6±0.3 to 25.9±3.7 min, respectively. The z (thermal resistance) values for FCV-F9, MNV-1, and HAV were 11.3±2.1°C, 11.0±1.6°C, and 13.4±2.6°C, respectively, using the Weibull model. The z values using the first-order model were 11.9±1.0°C, 10.9±1.3°C, and 12.8±1.7°C for FCV-F9, MNV-1, and HAV, respectively. For the Weibull model, estimated activation energies for FCV-F9, MNV-1, and HAV were 214±28, 242±36, and 154±19 kJ/ mole, respectively, while the calculated activation energies for the first-order model were 181±16, 196±5, and 167±9 kJ/ mole, respectively. Precise information on the thermal inactivation of HNoV surrogates and HAV in turkey deli meat was generated. This provided calculations of parameters for more-reliable thermal processes to inactivate viruses in contaminated presliced ready-to-eat deli meats and thus to reduce the risk of foodborne illness outbreaks.