Investigation of deactivation of mold conidia by infrared heating in a model-based approach

Concerns over chemical residue from chemical processing of fresh agricultural produces encourage the rise of alternative chemical-free methods. Infrared heating is a postharvest technique employed to reduce microbial load adhering on the surface of fresh fruits. The main purpose is to heat the produce surface to certain degree to achieve commercial sterilization while preventing quality degradation from overheating of internal tissue. In this study, we developed a microbial deactivation model combined with time-temperature profile of infrared heating with consideration of evaporation effect to evaluate the efficacy of the treatment and assess resulting surface temperature. Heating intensity controlled by heating distances was also investigated. As the result, the proposed model predicted the surface temperature profiles of potato dextrose agar (PDA) well at all points within a mean error of ±2.0 °C. The model will be able to apply for the surface decontamination of fruit and help to minimize microbial threats without heat damage to the quality.