Synergistic Effect of Acoustic and Vacuum Drying to Antioxidant Attributes of Cordyceps militaris

Abstract

Acoustic drying allows the utilization of lower temperatures than conventional methodology in the drying process. Vacuum drying is one of the most energy demanding processes. Water evaporation also takes place at lower temperatures under vacuum and hence the product processing temperature can be significantly lower, offering higher product quality. Cordyceps militaris is a well-known entamophagus fungus with wonderful health benefits such as adaptogenic, aphrodisiac, anti-oxidant, anti-aging, neuroprotective, nootropic, immunomodulatory, anti-cancer and hepatoprotective role by its phytochemical constituents. This study focused on the synergistic effects of acoustic and vacuum drying on antioxidant properties of Cordyceps militaris. We noticed that acoustic drying at power 800 W in frequency 40kHz combined with vacuum drying at pressure -0.8 bar were suitable for dehydration of this valuable material. From this approach, a combination of acoustic and vacuum drying created a synergistic effect consuming less energy than single drying method because it can be performed at low temperature while maintaining the product quality and wholesomeness. Moisture content is partly removed by acoustic drying and further dehydration in a vacuum dryer to reduce moisture to a stable level.