Continuous Radiofrequency-Assisted Thermal Processing of Packaged Soft Wheat Flour

Abstract

Soft wheat flour (SWF) is a low-moisture food ingredient in many ready-to-eat foods. Foodborne illnesses and outbreaks from consumption of multiple low-moisture foods heightened the importance of its microbiological safety. Traditional thermal processing methods take a long time to achieve desired pasteurization and are not suitable for processing the packaged products. The novel continuous radiofrequency (RF)-assisted thermal processing for packaged SWF was investigated with an objective of reducing the processing time. The temperature profiles in packaged SWF during RF heating at eight different locations under the stationary and moving conditions were investigated. The temperature difference between the coldest and the hottest locations in stationary RF heating of packaged SWF was 31°C. When the package was flipped up-side down along the long axis in stationary condition, the temperature difference was reduced to 24°C. The RF heating uniformity of packaged SWF with the conveyor movement improved and the temperature difference between the hottest and the coldest locations under this condition was only 15°C. The quality parameters of packaged SWF at 80°C for 7 h were not significantly different from that of the unpasteurized and batch mode processed SWF. This study demonstrated the continuous RF-assisted thermal processing of packaged SWF.