추출조건에 따른 귀리겨 ${eta}$-glucan의 추출조건을 확립하기 위하여 추출온도($40{sim}60^{circ}C$), 추출용매의 에탄올 농도(0~20%) 및 pH(5~9)를 변수로 중심합성계획법으로 설계하여 ${eta}$-glucan 추출특성을 조사하였다. 추출시간의 증가에 따라 ${eta}$-glucan의 추출속도는 추출초기에 급격히 증가하였으나, 이후에는 완만하였다. 총괄물질전달계수는 $3.363{sim}8.552{ imes}10^{-6}cm/min$ 범위로 낮은 추출온도에서는 추출용매의 농도가 낮을수록, 높은 추출온도에서는 추출용매의 농도가 높을수록 증가하였지만 pH에 의한 영향은 적은 것으로 나타났다. 추출용매의 pH는 중성일 때보다 산성이나 알칼리성일 때 ${eta}$-glucan의 추출량이 증가하였다. 추출조건에 따라서 ${eta}$-glucan 수용액의 점도는 유의적인 차이를 보였으며, 총괄물질전달계수가 높을수록 crude ${eta}$-glucan 수용액의 점도가 높게 나타났으며, 점도, 추출율 및 총괄물질전달계수의 상관관계를 분석한 결과, 각각의 요인들이 높은 양의 상관관계(p<0.01)를 나타내었다.
This study investigated the effects of temperature, solvent concentration, and pH on the ${eta}$-glucan extraction. Oat bran ${eta}$-glucan was extracted with different extraction conditions, using various combinations of experiment factors, such as temperature (40, 45, 50, 55, and $60^{circ}C$), ethanol concentration (0, 5, 10, 15, and 20%), and pH (5, 6, 7, 8, and 9). Under the various extraction conditions, ${eta}$-glucan extraction rate and overall mass transfer coefficient of oat bran ${eta}$-glucan, and viscosity of oat bran extracts were investigated. As increasing the extraction time, the extraction rate of ${eta}$-glucan increased. The overall mass transfer coefficient of ${eta}$-glucan ranged from $3.36{ imes}10^{-6}$ to $8.55{ imes}10^{-6}cm/min$, indicating the lowest at the extraction condition of $45^{circ}C$, 15% and pH 8, and the highest at $50^{circ}C$, 0% and pH 7. It was significantly greater with increasing extraction temperature and decreasing ethanol concentrations of extraction solvent, except for solvent pH. There were positive correlations among the overall mass transfer coefficient, the extraction rate of ${eta}$-glucan, and the viscosity of extract.
