Fermenting liquid vinegar with higher taste, flavor and healthy value by using discarded Cordyceps militaris solid culture medium

Cordyceps militaris has entered a large-scale artificial cultivation, and the solid culture medium of Cordyceps militaris are usually discarded. In this study, two kinds of liquid vinegars were prepared with discarded solid culture medium of Cordyceps militaris and rice, respectively. The contents of tartaric, methanoic, lactic and total organic acids were higher in cordyceps vinegar than in rice vinegar. Cordyceps vinegar showed higher antioxidant activity than rice vinegar. Moreover, cordyceps vinegar contained higher cordycepin and adenosine. The contents of sweet and umami free amino acids in cordyceps vinegar were higher than those in rice vinegar. Meanwhile, flavor groups such as esters and acids in cordyceps vinegar also significantly improved. According to sensory analysis, cordyceps vinegar showed higher intensity for sweet and umami attributes, as well as fruity attributes. Thus, discarded solid culture medium of Cordyceps militaris can be used to ferment liquid vinegar and improve the flavor and quality of vinegar, thereby indicating additional economic benefits of fermentation.