A novel combination of enzymatic hydrolysis and fermentation: Effects on the flavor and nutritional quality of fermented Cordyceps militaris beverage

Abstract

This study evaluated the effects of enzymatic hydrolysis and fermentation on the flavor and nutritional quality of fermented Cordyceps militaris beverage. Enzymatic hydrolysis can produce more reducing sugars and provide an appropriate fermentation substrate for the growth of bacteria. Electronic nose (e-nose) analysis indicated that first enzymatic hydrolysis and then two-step fermentation could significantly increase the volatile flavor component response values of the fermented beverage. Moreover, electronic tongue (e-tongue) analysis indicated that the fermentation process can increase the sourness and decrease the bitterness of the beverage, resulting in attaining a better taste. Based on the research undertaken on nutritional quality of this fermentation beverage, it was found that a combination of cellulase and pectinase with the ratio of 2:3 yielded higher cordycepin content. After fermentation, the retention rate of cordycepin was also high (98.02%). Fermented beverage pretreated with complex enzymes had a stronger antioxidant capacity compared with non-enzymatic group, which was indicated by the hydroxyl radical scavenging rate and reducing power determination. This fermented C. militaris beverage is expected to help to develop a functional beverage and further research can be carried out on the shelf-life of this beverage.