Articles
APPLICATION OF A COMPLETE HEAT-WATER MODEL TO PREDICT MICROBIAL GROWTH AND INACTIVATION DURING AIRFLOW TREATMENTS AT THE SURFACE OF MEAT PRODUCTS
Article number
674_33
Pages
285 – 292
Language
English
Abstract
A previously developed water transfer model is combined to a microbial model to predict the growth of Listeria innocua CLIP 20595 during the storage and slow drying of meat products.
The same water transfer model is coupled to a thermal model to predict the rapid evolution of surface temperature Ts, and water activity aw, during the dry air decontamination of beef lean meat.
Storage predictions were validated in a wind tunnel where bacterial growth was measured at the surface of gelatine gels for several days under constant air temperature and three different controlled air velocity and relative humidity conditions.
Predictions of Ts and aw during decontamination treatments were validated in a rig where the surface temperature was measured by a calibrated infrared sensor under controlled air properties conditions. aw was determined from sample weight losses measured at different time intervals during the treatment.
Wind tunnel experiments showed that L. innocua growth was stopped at a relative humidity of 92.5% and a velocity of 4.6 m/s.
The maximum population did not exceed 5 log10(CFU/cm²). The different behaviors of L. innocua under the three drying conditions were accurately predicted by the combined water transfer/growth models.
For the surface decontamination treatment, comparison with measurements proved that the coupled heat-water model was able to calculate accurately the temperature and water activity at the surface of a meat sample even under rapidly changing conditions.
The surface temperature and aw calculated by the transfer model were used in an inactivation model to predict microbial decontamination of S. Typhimurium, based on parameters estimated in the literature.
The same water transfer model is coupled to a thermal model to predict the rapid evolution of surface temperature Ts, and water activity aw, during the dry air decontamination of beef lean meat.
Storage predictions were validated in a wind tunnel where bacterial growth was measured at the surface of gelatine gels for several days under constant air temperature and three different controlled air velocity and relative humidity conditions.
Predictions of Ts and aw during decontamination treatments were validated in a rig where the surface temperature was measured by a calibrated infrared sensor under controlled air properties conditions. aw was determined from sample weight losses measured at different time intervals during the treatment.
Wind tunnel experiments showed that L. innocua growth was stopped at a relative humidity of 92.5% and a velocity of 4.6 m/s.
The maximum population did not exceed 5 log10(CFU/cm²). The different behaviors of L. innocua under the three drying conditions were accurately predicted by the combined water transfer/growth models.
For the surface decontamination treatment, comparison with measurements proved that the coupled heat-water model was able to calculate accurately the temperature and water activity at the surface of a meat sample even under rapidly changing conditions.
The surface temperature and aw calculated by the transfer model were used in an inactivation model to predict microbial decontamination of S. Typhimurium, based on parameters estimated in the literature.
Authors
A. Kondjoyan, I. Lebert, V.P. Valdramidis, A.H. Geeraerd, M.S. McCann, A. Lebert, J.F. Van Impe
Keywords
transfer, temperature, water activity, bacterial evolution, modelling.
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