Effects of Enzyme Treatment on Physicochemical Characteristics of Small Red Bean Percolate

팥 침출액의 이화학적 특성에 대한 효소처리의 영향

Effect of enzyme treatment on physicochemical characteristics of small tea bean percolate were estimated. Three types of small red bean percolate were prepared by heat treatment for 30 min at $95^{\circ}C$ (1st), 30 min at $95^{\circ}C$ (2nd), and 40 min at $120^{\circ}C$ (3rd). They were then treated with 0.5% ${\alpha}-amylase$ (v/v) for 4 hr at $108^{\circ}C$ (${\alpha}-amylase$ treatment), then with 0.5% ${\beta}-amylase$ (v/v) for 4 hr at $60^{\circ}C$ (${\alpha}-$ and ${\beta}-amylase$ treatment). Crude saponin contents of 1st-3rd percolates were 0.82, 1.44, and 1.52 mg/g, respectively. ${\circ}Brix$ of small red bean percolates treated with enzymes increased to $0.8-1.2\;{\circ}Brix$ with 2nd and 3rd percolates showing no significant difference between ${\alpha}-amylase$ and ${\alpha}-$ and ${\beta}-amylase$ treatments. pH of 3rd percolate treated with ${\alpha}-$ and ${\beta}-amylase$ decreased from initial 6.2 to 4.7. Hunter L value of small red bean percolate treated with ${\alpha}-$ and ${\beta}-$ decreased, whereas a and b values increased. Small red bean beverage made with 3rd percolate showed high score in flavor, taste, and overall acceptability. Results suggest small red bean percolate treated with enzymes could be used for preparation of small red bean beverage.

팥 1차, 2차 및 3차 침출액의 조사포닌 함량은 각각 0.82, 1.44 및 1.52mg/g으로서 침출 횟수가 늘어남에 따라 증가하였다. 팥 침출액에 ${\alpha}-amylase$ 처리시 ${\circ}Brix$가 $1.0{\circ}Brix$ 정도 증가하였으며, ${\circ}Brix$의 증가는 효소처리보다 침출 횟수에 의해 더 큰 영향을 받았다. 침출액의 pH는 효소처리에 의해 감소하는 경향을 나타냈으며 3차 침출액에 ${\alpha}-$와 ${\beta}-amylase$를 동시 처리한 경우 pH 4.7로서 대조구(pH 6.2)보다 많이 낮아졌다. 색도의 경우 일반적으로 효소처리에 의해 침출액의 L값이 감소하고 a와 b 값은 모두 증가하는 경향을 보였으며 이는 육안으로 충분히 관찰할 수 있었다. 팥의 3차 침출액을 사용하여 음료 시제품을 제조한 결과 관능적인 면에서 적용이 가능한 것으로 판단되었다.