Assessment of drying methods on the physiochemical property and antioxidant activity of Cordyceps militaris

Drying is an important method in the preservation of food and plant materials. The effects of sun-drying (SD), freeze-drying (FD), hot air drying (50 degrees C, 70 degrees C; HD) and microwave drying (420W, 700W; MD) on the physiochemical properties and antioxidant activities of Cordyceps militaris were examined. Results showed that freeze-drying led to the lowest color difference and maintained more cordycepin and polysaccharide. Microwave drying at 700W helped to preserve larger amounts of phenolic compounds and carotenoids, so showed higher DPPH and ABTS free radicals scavenging activities and ferric reducing antioxidant power. Therefore, microwave drying should be a potential method for obtaining dried C. militaris with high antioxidant activity.