쌀보리의 무증자 Alcoho 효소에 관한 연구

Alcohol Fermentration of Naked Barley without Cooking

주정효소의 전분질 원료인 쌀보리 (Naked barley)에 대한 분해, 당화작용이 강한 maceration enzyme 및 glucoamylase 를 검토하고 이 효소들을 이용한 무증자 alcohol효소에 대하여 연구하였다. 이 효소들은 곰팡이 기원의 조효소제로서 쌀보리입자의 maceration 작용이 강하였고 생전분 분해력은 pH4.5, 온도 3$0^{\circ}C$, 76시간에서 70% 이상되었다. 또한 황산을 요에 대하여 0.15%(w/v)되도록 가하고 55$^{\circ}C$에서 2시간 동안 침지한 후 이 효소들을 처리하여 무증자 alcohol 발효를 행한 경우, 3$0^{\circ}C$, 96시간 발효에서 alcohol 농도가 10.8%, 발효 효율이 89.5%로서 증자 alcohol 발효에 비해 고농도의 alcohol이 생성되었고 약 3.5% 정도의 효율증가를 나타내었다.

Alcohol fermentation of uncooked naked barley was carried out by the combined action of the maceration enzyme from black Aspergillus niger and the glucoamylase from Rhizopus sp. The combined enzyme preparation was found to be effective in maceration and saccharification of the raw naked barley starch. The Hydrolysis rate measured by the amount of glucose liberated reached more than 70% at pH 4.5 and 3$0^{\circ}C$ after 76 hrs. For alcohol fermentation without cooking, the naked barley mash of 18% initial total sugar was pretreated with concentrated sulfuric acid (0.15 weight % of the mash volume) at 55$^{\circ}C$ for 2hr, and used for alcohol fermentation. A simultaneous saccharification and fermentation was carried out at pH 4.8 and 3$0^{\circ}C$ for 96 hrs. Under this fermentation condition, 3.5% increase in alcohol yield together with 2.0% increase in alcohol concentration were obtained when compared with the conventional cooking fermentation.