Non-uniform heating caused by different size, geometry and properties of agricultural crops is a major challenge that needs to be addressed in developing industrial-scale radio frequency (RF) treatments for postharvest phytosanitary and quarantine applications. A mathematical model based on normal distributions of product temperatures and taking into account insect thermal mortality and product quality was developed to predict treatment temperature-time ranges as a function of number of mixing. Thismodel was validated by experimental data of the uniformity index and applied for different agricultural commodities, walnut, soybean, lentil and wheat, each with its own unique RF heating characteristics. The results showed that the operation ranges (temperature-time combinations) for effectively controlling pests without causing adverse quality changes expanded with increasing mixing number and the improved heating uniformity. This study suggested more flexibility in developing RF treatments of pest control for small-size crops with better heating uniformity, as compared to large size crops.
展开▼
