2.3.2. Enzymatic pretreatment (Variant II)
Raw material samples (30 g dry matter basis) were slurred in ca. 150 mL of distilled water in a 300 mL conical flasks and pH of the slurry was adjusted to 4.5 using 1 mol LÀ1 H2SO4 solution. Then Ceremix 6X MG preparation (1.25 g of enzyme per kilogram of raw material dry matter) was added and the total weight of the flask content was adjusted to 200 g with distilled water. The flasks were sealed with rubber stoppers to avoid water evaporation and were placed in a water bath heated to 45 °C for 20 min with constant agitation. Afterwards the slurries were cooled to 35 °C, inoculated with yeast, GSHE and protease (Neutrase 0.8 L) were added and further procedure was the same as described in the Sec-
tion 2.3.1.
2.3.3. Microwave pretreatment (Variant III)
Raw material samples (30 g dry matter basis) were spread in a thin layer on a Petri dish and irradiated in a microwave oven KOR-63X5 (Daewoo, China) for 2 min with 400 W microwave power output and 2450 MHz frequency. After the pretreatment samples were cooled to room temperature in a desiccator. Further procedure was the same as in Section 2.3.1.