Abstract
The changes in gelatinization patterns of potato were investigated while steeping in water for 7 days at 30${\pm}$1$^{\circ}C$. The transmittance of 0.1% starch suspension was increased rapidly from 60$^{\circ}C$ in raw starch and the starch steeped for 2 days, and increased rapidly from 65$^{\circ}C$ in the starch steeped for 4 and 6 days. As the steeping period increased, the transmittance was decreased at above condition. The gelatinization temperature of the starch measured by differential scanning calorimetry was increased from 62.79$^{\circ}C$ to 63.72$^{\circ}C$ as the steeping period increased. The gelatinization enthalpy reached the maximum in the starch steeped for 4 days. By amylograph, the initial gelatinization temperature was increased from 66$^{\circ}C$ to 84$^{\circ}C$ as the steeping period increased. Peak viscosity was decreased during steeping and the starch steeped for 5 days had no peak viscosity. Peak height after cooling to 50$^{\circ}C$ was increased up to the 4th day and began to decrease. As the steeping period increased, there was much loss of birefringence at higher temperature. The crystallinity by X-ray diffraction disappeared from 65$^{\circ}C$.
