Ball milling improves extractability and antioxidant properties of the active constituents of mushroom Inonotus obliquus powders

Summary Inonotus obliquus has been used as a folk remedy for a long time. An improved method using fine grinding by ball mill was investigated, and the main chemical components and physicochemical properties of Inonotus obliquus powders were analysed. The Inonotus obliquus fine grinding powders were prepared by pulverising the coarse powder with planetary ball mill for different time. The results showed that the yields of polysaccharides increased from 41.08 mg g−1 (coarse powder) to 319.62 mg g−1, and the yields of polyphenols were also increased fourfold in ball-milled powders as compared to the untreated one. Ball-milled powders showed higher values in the bulk density, angles of repose and slide, water solubility index and swelling capacity (P < 0.05), but lower values in the water-holding capacity and oil-holding capacity. The shape and surface morphology of the powders were changed after ball mill treatment. The antioxidant properties of the extracts from ball-milled powders were significantly improved (P < 0.05). The results will be helpful for the application of Inonotus obliquus in food and pharmaceutical industries.