Research on sugarcane juice fermentation by Ganoderma lucidum and assay of antioxidant activity of exopolysaccharide

Abstract

A protocol for processing of the Ganoderma lucidum fermentation was carried out using sugarcane juice at 28°C for 14 d. The nonlinearity logistic growth curve model of G. lucidum is successfully fitted and the ideal highest biomass is estimated to be 5.42 g/L. G. lucidum was found to have a significant decrease effect on the pH value and sugar in sugarcane juice. The lowest pH (3.87 ± 0.01) was found on the 3rd day during fermentation. To the contrary, the release of exopolysaccharides and protein content noticeable increased, and free amino acids greatly enriched after the fermentation. Antioxidant activity tests showed exopolysaccharides can remarkably scavenge hydroxyl radicals, superoxide anion free radicals and DPPH free radicals. The sugar content of sugarcane juice was reduced by the fermentation of G. lucidum, and the content of active ingredients, such as polysaccharide increased, so it could be used as a new source of healthy foods. Practical applications Sugarcane is a traditional cash crop, which plays a pivotal role in many countries. As is well-known, sugarcane juice fermentation drinks are comparatively uncommon in the market. The application of sugarcane juice fermentation by Ganoderma lucidum could combine the nutrients and health benefits of both sugarcane juice and G. lucidum, which provide a new way for sugarcane juice products processing. Fermented sugarcane juices may be developed into functional drinks for specific people.