Timothy D. Durance

Efficacy of Vacuum Microwave Drying in Microbial Decontamination of Dried Vegetables

The efficacy of vacuum microwave drying and a combination of microwave processing at atmospheric pressure + vacuum microwave drying on decontamination of freshly grated carrots and parsley leaves from naturally occurring microorganisms was studied. Samples were dried to < 8% moisture content under microwave radiation (2450 MHz, 1.8 kW) with either full vacuum or combination of 12 min atmospheric pressure and 46 min vacuum process. In the microwave under vacuum process the microbial population was reduced gradually as the exposure time increased, while in the combined method a dramatic decrease in microbial counts after 5 min exposure to microwave radiation at atmospheric pressure was observed.