S. Veelaert, D. D. Wit, Kf Gotlieb
Jun 1, 1997
Citations
2
Influential Citations
105
Citations
Quality indicators
Journal
Carbohydrate Polymers
Abstract
Abstract Physical and chemical transitions of dialdehyde starch in aqueous suspensions have been determined as a function of temperature and pH. The pH conditions were restricted to neutral or lower, since alkaline degradation is commonly recognized. Physical alterations were determined by measuring viscosity transitions at room temperature and upon heating. Chemical degradation was surveyed by controlling the amount of aldehydes, the production of carboxylic acids and the decrease in molecular weight. At neutral conditions and upon heating at 90 °C extensive chemical degradation occurred. This was manifested by a gradual conversion of aldehydes into carboxylic acids and alcohols, accompanied by a decrease in molecular weight. Degradation upon heating was minimized by reducing the pH to 3. At ambient temperature, the granular integrity was lost beyond pH 5 or 6 depending on the degree of oxidation of the material.