Developing Radio Frequency Treatment Protocol for Disinfesting Coffee Beans

摘要

The objective of this study was to develop novel non-chemical treatments for postharvest disinfesting coffee beans using radio frequency (RF) energy. A pilot-scale 27 MHz, 6 kW RF unit was used to study heating uniformity, develop a treatment protocol, and evaluate quality attributes in treated coffee beans. After comparing 3 selected electrode gaps, an appropriate gap of 14 cm was obtained to raise the central temperature of 2.75 kg samples to 48°C using RF energy by 4.6 min, compared to more than237 min using forced hot air at 48°C. RF heating uniformity in beans was improved by adding forced hot air, and back and forth movements. The final temperatures reached 50.4°C and 50.6°C, resulting in uniformity index values of 0.060 and 0.073 for interior and surface temperature distributions, respectively. No significant differences in weight loss, moisture content, and color were observed between RF treatments and unheated controls.