Comparison of sterol composition between Tuber fermentation mycelia and natural fruiting bodies

Truffle, belonging to Tuber genera, is a nutritious and sterol-rich edible fungus, and sterol is a potential health beneficial compound. A comparison of Tuber sterol composition indicates that the total sterol contents in the fermentation mycelia (i.e., 10.5mgg^-1) (n=3) were approximately 3.2-5.6 times higher than that of the fruiting bodies (p<0.05) with the addition of soybean flour into the basal fermentation media. Moreover, the phytosterol profile of fermentation mycelia could be significantly improved by adding soybean flour into the fermentation media. After the addition of soybean flour, stigmasterol and β-sitosterol appeared in the fermentation mycelia and the contents of total phytosterols (2279μgg^-1) (n=3), brassicasterol (943μgg^-1) (n=3), and campesterol (418μgg^-1) (n=3) were all increased significantly (p<0.05). Moreover, the total contents of sterols and phytosterols in the fermentation mycelia cultured in the soybean media were much higher than those in the fruiting bodies (i.e., 1883-3240 and 479-1832μgg^-1, respectively) (n=3, p<0.05). This work confirms the potentiality of Tuber fermentation mycelia as the alternative resource for its fruiting bodies from the viewpoint of sterols production.