Physicochemical Properties of Chestnut Starch According to the Processing Method

전분 제조방법에 따른 밤전분의 이화학적 특성

This study is to investigate the physicochemical properties of differently pretreated chestnut starches during starch isolation and to examine their gelatinization properties by both heat and alkali treatments. One kind is starch A made by alkali method from peeled chestnut. The other is starch B made from chestnut with the outer layer. The results are as follows. Starch A has higher water binding capacity of 86.9% than starch B with 80.66%. Swelling powers of both starch A and B increased rapidly from $60^{\circ}C\;to\;80^{\circ}C$ in both, and since then it has changed a bit. Both began to show their solubility at $60^{\circ}C$ and increased continuously as the temperature went up. Starch A has higher swelling power and solubility than starch B. In iodine reaction, starch A has higher ${\lambda}max$ and absorbance at ${\lambda}max$ than starch B. X-ray diffraction patterns showed that starch A is type $C_b$ and that starch B is type B. Starch B has higher relative crystallinity of 37.0% than starch A with 36.2%. The results by differential scanning calorimetry revealed that starch A gelatinized from $66.95^{\circ}C$ to $77.5^{\circ}C$ and its enthalpy is 2.04 cal/g. And starch B gelatinized from $67.09^{\circ}C\;to\;77.5^{\circ}C$, and its enthalpy is 2.29 cal/g. Amylograms of chestnut starch at 6.5% concentration indicated that starch B needs higher onset temperature when beginning to gelatinize than starch A does. But starch A shows much higher peak viscosity, breakdown and setback than starch B does. Starch A shows higher viscosity, gel volume, and optical transmittance in gelatinization properties by alkali than starch B does.

알칼리 침지법에 의하여 박피한 밤 전분과 박피하지 않은 밤 전분의 이화학적 특성, 가열 및 알칼리에 의한 호화특성을 각각 분석한 결과는 다음과 같다. 물결합력은 박피한 A전분의 경우86.9%, 박피하지 않은 B전분은 80.66%로 박피한 A전분이 더 높은 물결합력을 나타냈다. A전분과 B전분의 팽윤력은 $60^{\circ}C$에서 급격히 증가하기 시작하여 $80^{\circ}C$까지 증가하다가 그 이후는 완만하게 변하였고, 용해도는 $60^{\circ}C$에서부터 증가하기 시작하여 온도가 상승함에 따라 점점 증가하는 특성을 보였으며, A전분이 B전분보다 팽윤력과 용해도가 더 높게 나타났다. 요오드 반응은 A전분이 B전분보다 더 높게 났다. X-선 회절도는 A전분은 $C_b$도형, B전분은 B도형으로 나타났고, 상대적 결정화도는 A전분이 36.2%, B전분은 37.0%로 B전분이 더 높게 나타났다. DSC에 의하여 측정한 호화온도 및 호화엔탈피는 A전분의 경우 $66.95^{\circ}C{\sim}77.5^{\circ}C$, 2.04 cal/g, B전분의 경우 $67.09^{\circ}C{\sim}77.5^{\circ}C$, 2.29 cal/g으로 나타났다. 6.5% 밤 전분의 아밀로그램 특성은 A전분보다 B전분이 호화개시 온도가 더 높았고, peak viscosity, break-down, setback은 A전분이 B전분보다 더 높았다. 알칼리에 의한 호화특성에서 A전분이 B전분보다 점도, gel 부피 및 광투과도가 더 높게 나타났다.