Nutritional Composition and Cordycepin Content of Cordyceps militaris Cultivated on the Edible Cricket Gryllus bimaculatus

Abstract

Cordyceps militaris was cultivated on a cricket-based host substrate using whole adults of Gryllus bimaculatus (WGB), which was compared with a brown rice control (CTR) and a brown rice medium supplemented with G. bimaculatus powder (GBP), where f and m denote fruiting bodies and mycelia, respectively. On a dry-matter basis, WGB-m increased crude protein from 5.8% ± 0.4% (CTR-m) to 68.0% ± 1.2% (WGB-m), an 11.7-fold increase, and raised crude lipid from 2.3% ± 0.2% to 5.2% ± 0.3%. In the fruiting bodies, the crude protein content of WGB-f was 1.5-fold higher than that of CTR-f. Amino acid levels increased markedly in the WGB-m group, including tyrosine (30.6-fold), proline (18.5-fold), lysine (14.6-fold), and branched-chain amino acids (isoleucine, 8.3-fold; leucine, 6.5-fold). Mineral content was higher in WGB-m than in CTR-m, with increased levels of calcium, zinc, and iron, while heavy metal concentrations remained below the guideline limits across treatments. Cordycepin content also increased substantially in the whole-insect substrate, reaching 4624.33 mg/kg in WGB-f (3.2-fold relative to CTR-f) and 2529.64 mg/kg in WGB-m (4.6-fold relative to CTR-m), whereas GBP showed no improvement and was slightly lower than the corresponding CTR. Collectively, these results indicate that cultivation on whole G. bimaculatus adults was associated with higher levels of selected nutritional components and cordycepin in C. militaris while ensuring heavy metal safety.