| Summary: | 碩士 === 明新科技大學 === 化學工程與材料科技系碩士班 === 102 === Cordyceps militaris belongs to Clavicipitaceae with ingredients similar to Cordyceps sinensis. The wild Cordyceps militaris is a rare medicinal fungus but it can be produced by artificial culture. In addition, Cordyceps militaris is a precious medicinal fungus. Polysaccharides represent a major class of the bioactive compounds of Cordyceps and most other medicinal fungi or mushrooms with proven and notable anticancer and immunomodulatory activities, and possible hypoglycemicand hypolipidemic effects. As the limited natural resource of Cordyceps cannot meet the increasing demand for herbal medicine and health food applications, mycelial fermentation has been widely used to produce Cordyceps mycelial biomass and components. This study was mainly to produce Cordyceps militaris mycelia by solid-fermented Cordyceps militaris and to evaluate extraction optimization of polysaccharide from the produced Cordyceps militaris mycelia, and also demonstrated antioxidant properties. In this study, response surface methodology (RSM) was employed to optimize the extraction process of polysaccharide from the produced Cordyceps militaris mycelia using Box-Behnken design (BBD). The experimental data obtained were fitted to a second-order polynomial equation using multiple regression analysis. Statistical analysis showed that the polynomial regression model was in good agreement with the experimental results with the determination coefficient (R2) of 0.9242. the extraction parameters were optimized as 4.68 h for extraction time, 100 °C for extraction temperature, 29.8 (v/w) for ratio of water volume (mL) to raw material weight (g), and with 2 extractions. The maximum value (280.55 mg/g) of polysaccharide yield was obtained when the polysaccharide extraction process was conducted under the optimal conditions. The antioxidant properties of the extracted polysaccharide from Cordyceps militaris mycelia were also examined. The results told that Cordyceps polysaccharide at 10 mg/ml showed a reducing power of 1.57, a scavenging DPPH radical ability of 39.97%, and a chelating ability of 73.74%. For polysaccharide at 5 mg/ml, an antioxidant activity is 82.50% and a scavenging superoxide radical ability is 74.22%. Based on results obtained, polysaccharide produced by solid-fermented Cordyceps militaris mycelia possess better antioxidant properties, and can act as a source potential for application in health food.
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