Radiofrequency-Assisted Thermal Processing of Soft Wheat Flour

摘要

Wheat flour may be thermally processed to improve microbiological safety; however, come-up time for thermal processing of wheat flour is long due to its low thermal conductivity. In the present study, a novel radiofrequency (RF)-assisted thermal processing approach was investigated for reducing the come-up time of soft wheat flour (SWF) and for improving microbiological safety. The temperature and time combinations of 80 degrees C for 7 and 10 hr, 90 degrees C for 2 and 3 hr, and 100 degrees C for 0.75 and 1 hr for RF-assisted thermal processing were selected to achieve a minimum of a 7-log reduction in Salmonella spp. The quality and functional properties of RF-assisted thermally processed SWF was evaluated by solvent retention capacity (SRC), swelling power, sodium dodecyl sulfate sedimentation tests, and rapid-visco-analyzer test, and the values were compared with the untreated (unpasteurized) and commercially pasteurized SWF. All the SRC attributes at 80 degrees C for 7 hr, 90 degrees C for 2 hr and 100 degrees C for 0.75 hr were not significantly different from that of the unpasteurized SWF. The optimum RF-assisted thermal processing conditions of 80 degrees C for 7 hr and 90 degrees C for 2 hr were recommended for pasteurization of SWF without any compromise in the quality and functionality. Practical application Thermal processing of low-moisture foods such as flours and powders through traditional methods is not practical due to extremely long come-up times. Novel radiofrequency-assisted thermal processing is poised to reduce the processing time 89 times for 100 degrees C. The processing parameters determined in this study will enhance the microbiological safety of wheat flour without compromising the quality and functionality.