The Food and Agriculture Organization (FAO) has been estimating the potential of insects as human food since 2010, and for this reason, Tenebrio molitor larvae, also called mealworms, have been explored as an alternative protein source for various foods. In this study, in order to increase nutrient contents and improve preference as an alternative protein source, we fermented the T. molitor larvae by Cordyceps militaris mycelia. T. molitor larvae were prepared at optimal conditions for fermentation and fermented with C. militaris mycelia, and we analyzed T. molitor larvae change in functionality with proximate composition, β-glucan, cordycepin, adenosine, and free amino acids content. T. molitor larvae fermented by C. militaris mycelia showed higher total protein, total fiber, and β-glucan content than the unfermented larvae. In addition, the highest cordycepin content (13.75 mg/g) was observed in shaded dried T. molitor larvae fermented by C. militaris mycelia. Additionally, the isolated cordycepin from fermented T. molitor larvae showed similar cytotoxicity as standard cordycepin when treated with PC-9 cells. Therefore, we report that the optimized methods of T. molitor larvae fermented by C. militaris mycelia increase total protein, total fiber, β-glucan and produce the amount of cordycepin content, which can be contributed to healthy food and increase T. molitor larvae utilization.

Beech mushrooms (Hypsizygus marmoreus) are edible mushrooms commercially used in South Korea. They can be classified into white and brown according to their pigmentation. This study analyzed the metabolites and biological activities of these mushrooms. Specifically, 42 metabolites (37 volatiles, two phenolics, and three carbohydrates) were quantified in white beech mushrooms, and 47 (42 volatiles, two phenolics, and three carbohydrates) were detected in brown mushrooms. The major volatiles detected were hexanal, pentanal, 1-hexanol, and 1-pentanol. Brown mushrooms contained higher levels of hexanal (64%) than white mushrooms (35%), whereas white mushrooms had higher levels of pentanal (11%) and 1-pentanol (3%). Most volatiles were more abundant in white mushrooms than in brown mushrooms. Furthermore, brown beech mushrooms had a higher phenolic content than white mushrooms. Biological assays revealed that both types of mushroom demonstrated anti-microbial activities against bacterial and yeast pathogens and weak DPPH scavenging activity. The extracts from both mushrooms (50 μg/mL) also exhibited strong anti-inflammatory properties. Brown mushroom extracts showed higher antioxidant, anti-microbial, and anti-inflammatory properties than white mushroom extracts. This study reported that the differences in phenotype, taste, and odor were consistent with the metabolite differences between white and brown beech mushrooms, which have high nutritional and biofunctional values.

Skin whitening has recently renewed attention on Chinese herbal medicines with whitening activity for esthetic applications. Stachys sieboldii has been used as herbal medicine since ancient times and has the potential for development as a cosmetic material because of its astringent effect. In this study, with an aim to develop new functional materials with whitening effects, S. sieboldii water extracts were fermented with different mushroom mycelia. Fermented with Hericium erinaceus mycelia showed the strongest tyrosinase inhibition effect and the lowest melanin content. Thus, H. erinaceus mycelia, the most potent inhibitor of melanogenesis, was used for large-scale fermentation and fractionated. The ethyl acetate fraction, which had the strongest whitening activity, was separated and purified using HPLC. Finally, the single compound was isolated and identified as acteoside, which has promising whitening activity. Acteoside inhibited melanin synthesis and intracellular tyrosinase activity in a dose-dependent manner. The effects of acteoside on the expression of TYR, TRP-1, TRP-2, and MITF were analyzed using Western blot analysis, which showed that acteoside reduced the protein in a dose-dependent manner. Our findings reveal the potential applicability of S. sieboldii extract fermented with H. erinaceus mycelia and its useful component, which is an acteosid, for skin lightening and the treatment of pigmentation.