Physical properties and enzymatic digestibility of hydroxypropylated ae, wx, and normal maize starch

The physical properties and enzymatic digestibility of hydroxypropylated st arches prepared from high amylose (Hi-Maize(TM), 66% amylose; GELOSE 50, 47 % amylose), waxy (MAZACA 3401X, 3.3% amylose), and normal (22.4% amylose) m aize starches were studied. For normal and high amylose starch, hydroxyprop ylation decreased the temperature at peak viscosity and caused a large incr ease in both the peak and cool paste viscosities. Hydroxypropylation had Li ttle effect on the pasting properties of waxy starch. All the hydroxypropyl ated starches had lower gelatinization parameters (T-o, T-p, T-c, and Delta H) than their unmodified and control starches, but hydroxypropylation incr eased swelling power and solubility. After hydroxypropylation, the hardness and adhesiveness of all the starch gels decreased. Hydroxypropylation incr eased the clarity and enzymatic digestibility of all the starches. (C) 1999 Elsevier Science Ltd. All rights reserved.