Exploration of the potential utilization value in Cordyceps militaris substrate after industrial cultivation in terms of nutritional and pharmaceutical applications.

ObjectiveA large number of substrates after harvesting the fruiting bodies of Cordyceps militaris have been discarded or only used as feed and fertilizer. In this study, we aimed to investigate the potential utilization value of residual substrates under industrial cultivation of C. militaris.MethodsThe various bioactive substances in C. militaris fruiting body and substrate were measured and compared by colorimetry, HPLC, burning method, Kjeldahl legal nitrogen method, and GC-MS et al. The fruiting body was taken as a reference to better reflect the internal quality of substrate. Finally, a response surface experiment was conducted to investigate the effects of drying temperature, humidity, and time on the retention rate of C. militaris polysaccharide.ResultsIn the substrate, the content of polysaccharide was 4.68%, the cordycepic acid content was 7.95%, which were significantly higher than the content in the fruiting body. The content of cordycepin was as high as 1.13%, which was more than 4 times of the fruiting body. The crude fat content was also higher than that in fruiting body. In addition, 17 amino acids were detected in the substrate, including 7 essential amino acids. Moreover, several volatile components with drug properties were detected in the substrate. Finally, the optimum drying parameters of the substrates are as follows: drying temperature, 59°C; humidity, 16%; time, 24 h.ConclusionsThis study highlighted the available value of substrate is no less than the fruiting body, which is an ideal food supplement and pharmaceutical agent, which can be served as a good source of healthy substances potentially bioavailable for humans.