Optimization of Polysaccharide Production from Cordyceps militaris by Solid-State Fermentation on Rice and Its...

Polysaccharides are an important class of bioactive components of medical mushroom and herbs and are now used as natural drugs or dietary supplements on a global scale. In this paper, we aimed to increase the polysaccharide production of Cordyceps militaris and the antioxidant activities of fermented rice by solid-state fermentation. The media components and culture condition were optimized by orthogonal design and mono-factor tests using rice as the raw material. The optimal media consisted of (g/L): rice (50), fructose (7), glycerin (7), peptone (1), MgCl₂ (0.11), VB₁ (0.05), VB₂ (0.05), CaCl₂ (1.5), corn bran (6), and a water-materials ratio of 100%. The fermentation condition was as follows: inoculum volume of 5.5% (v/w), rice weight of 50 g in one bowl with a diameter of 120 mm and a depth of 90 mm, incubation temperature of 26 °C, and incubation time of seven days. Under the optimized condition, the maximal C. militaris polysaccharide content and free radical scavenging ratio were 68.3 mg/g dry substrate and 98.9%, respectively. This study provides a new strategy for the production of healthy food from traditional food.