Investigation of far infrared radiation heating as an alternative technique for surface decontamination of strawberry

Abstract

Postharvest heat treatments have recently received attention as a means to prevent fungal spoilage of strawberry during shelf life. Far infrared radiation (FIR) heating technology may be an alternative to conventional methods because it can achieve rapid and contactless heating. Monte Carlo FIR radiation simulations combined with convection–diffusion air flow and heat transfer simulations were performed in the CFD code ANSYS CFX5.7 to investigate the suitability of the method for surface decontamination. Computations were validated against measurements with a thermographic camera. FIR heating achieved more uniform surface heating than air convection heating, with a maximum temperature well below the critical limit of about 50 °C at the same average temperature. In this configuration, the resulting surface FIR heating rate was, however, smaller or only equal to the air convection heating (at 0.2 m s −1), depending on the heater temperature used. A better configuration consisted of FIR heaters on four sides combined with a cyclic heating operation.