Characteristics of Ethanolic Cordyceps Militaris Extract by Ultrasonic-Assisted Extraction Method

Cordyceps militaris (CM) is a rare edible fungus belonging to the Cordycipitaceae family. This research investigated the effects of raw materials and extraction time on the extraction yield of CM. Furthermore, nutraceutical compositions of CM, such as cordycepin, adenosine, carbohydrates, phenolic compounds and antioxidant activity, were also assessed. Freeze-dried CM powder was shown to obtain a higher extraction yield than fresh one due to the difference in water content (26.57% compared to 4.59%, respectively). Data showed that the highest extraction yield of CM obtained from the ultrasonic-assisted extraction (UAE) method was 38.6 ± 0.04% at an extraction time of 180 min. Cordycepin and adenosine contents in the ethanolic extract at an extraction time of 60 min were highest among four screening time points which were 4.096 mg/g (0.81%) and 0.935 mg/g (0.18%), respectively. The content of carbohydrates in the ethanolic extract of CM was 280.28 ± 14.65 mg/g. Total phenolic and flavonoid content was 33.37 ± 3.30 mg GAE/g extract, and 15.40 ± 4.56 mg QUE/g extract, respectively. With the conventional DPPH method, CM extract was shown to be a weak antioxidant agent IC50 value of only 7.67 ± 0.20 mg/mL. Interestingly, with the same method but using acetate buffer instead of distilled water, CM turned out to be a good antioxidant agent with IC50 of 1.20 ± 0.13 mg/mL. This study provided useful data for further studies investigating the pharmacological activities of CM extract and the development of CM-derived functional foods and pharmaceutical products.