Effects of Non-Traditional Extraction Methods on Extracting Bioactive Compounds from Chaga Mushroom (Inonotus obliquus) Compared with Hot Water Extraction

Abstract

Chaga mushroom (Inonotus obliquus) has been known to have antioxidant, anti-virus, anti-inflammatory, and anti-tumor effects due to its bioactive compounds such as β-glucans, triterpenoids, phenolic compounds, and melanin complexes. This mushroom has been used as a folk remedy since the 16th century and mainly consumed as extracted. Hot water extraction, which is a traditional method preparing chaga mushroom extract, has limitations requiring a large amount of solvent and long extraction time, resulting in degradation and coagulation of bioactive compounds. The objective of this study was to develop efficient methods extracting bioactive compounds in chaga mushroom, compared with hot water extraction. High temperature and pressure, enzyme, and ultrasound extractions were used as non-traditional extraction methods. Chaga mushroom extracts were prepared under conditions determined by preliminary experiments. β-Glucans were higher in high temperature and pressure and enzyme extracts than in hot water extract. Total triterpenoids were higher in the enzyme and ultrasound extracts than in the hot water extract. Total phenolic compounds were higher in the high temperature and pressure extract than in the hot water extract. Major phenolic compounds in the chaga mushroom extracts, which were identified by HPLC, LC-MS, and GC-MS, were 3,4-dihydroxybenzaldehyde and coniferyl aldehyde, which were the highest in the high temperature and pressure and enzyme extracts, respectively. Antioxidant activities were the highest in the high temperature and pressure extract which had the highest content of phenolic compounds. In conclusion, high temperature and pressure and enzyme extractions may be efficient methods to produce chaga mushroom extracts with a large amount of bioactive compounds.