Chaga Extracts and Melanins After Plasma Treatment of Raw Material

The extracts and melanins of chaga (Inonotus obliquus (Pers.) Pil.) obtained by raw material pretreatment with high-frequency capacitive low-pressure plasma (RF-plasma) under different technological conditions were studied. The advantages of RF-plasma treatment of raw materials in three different plasma-forming media (argon, air, and nitrogen) were shown. In all cases, the modification of the natural particles surface affecting the extraction process was observed. Optimization of the extraction parameters demonstrated that best results (increase of the extractive compounds yield and higher antioxidant capacity) were achieved with the air-based plasma. The surface topology of the melanins under investigation was evaluated by atomic force microscopy (AFM). The difference of melanins structural features by roughness degree, height, and diameter of single particles in relation to the raw material RF-plasma treatment mode was shown that enabled a deeper insight into the nature of fungal melanins. Preliminary RF-plasma treatment of raw material can be recommended for Inonotus obliquus (Pers.) Pil. extraction while producing medications on their basis.