Apparent thermal death kinetics of adult red flour beetle (Tribolium castaneum) in stored canola (Brassica napus L.) seeds using a pilot-scale 50-Ω radio frequency (RF) heating system

Abstract

Adult Tribolium castaneum infesting canola seeds at 9% moisture content were treated using a 50-Ω radio frequency heating system and the thermal mortalities of the insects were determined. The infested seeds were treated at temperatures of 24–65 °C with radiofrequency (RF) heating power at 3 kW, 5 kW, and 7 kW. More than 80% of the insects were killed at 65 °C at all the three power levels. The survival rate of the adult T. castaneum decreased with temperature and RF power level. The effect of selective heating on mortality of insects increased at the higher RF powers. An inverse simulation was used to estimate the kinetic parameters of thermal death in adult T. castaneum. The thermal kinetic models developed in this study were solved using the 4th order Runge-Kutta method on a MATLAB platform. The thermal death kinetics for adult T. castaneum followed the 1st order reaction with Ea of 97.50 kJ/mol and k0 of 6.5 × 1013. The lethal time (LTs) calculated using the thermal death kinetic model developed in the study agreed well with the LTs determined experimentally.