Effect of one-step and two-step modified method on the property of cross-linked esterification sweet potato starch

Sodium trimetaphosphate was used as cross-linking agent and acetic anhydride as esterifying agent to prepare cross-linked esterification sweet potato starch through one-step and two-step modified method. The effect of one-step and two-step modified method on the property of cross-linked esterification sweet potato starch was compared in this study. As to one-step modified method, sweet potato starch slurry was adjusted to appropriate condition after being cross-linked and then esterified directly where wash, neutralization, dry was eliminated. As to two-step modified method, cross-linked sweet potato starch was well dried and smashed, which was used as the raw starch for the next step of esterification. Peak viscosity and stability were chosen as index and the result indicated that the cross-linked esterification sweet potato starch prepared by one-step modified method possess better peak viscosity and stability. The cross-linked esterification sweet potato starch prepared by two-step modified method possess better anti-precipitability and freezing-thaw resistance, slightly higher solubility, swelling power, but the difference between two methods was not obvious.