Exploring the Equilibrium State Diagram of Maltodextrins across Diverse Dextrose Equivalents

Abstract

This study investigates the equilibrium state diagram of maltodextrins with varying dextrose equivalents (DE 10 and 30) for quercetin microencapsulation. Using XRD, SEM, and optical microscopy, three transition regions were identified: amorphous (aw 0.07–0.437), semicrystalline (aw 0.437–0.739), and crystalline (aw > 0.739). In the amorphous region, microparticles exhibit a spherical morphology and a fluffy, pale-yellow appearance, with Tg values ranging from 44 to −7 °C. The semicrystalline region shows low-intensity diffraction peaks, merged spherical particles, and agglomerated, intense yellow appearance, with Tg values below 2 °C. The crystalline region is characterized by fully collapsed microstructures and a continuous, solid material with intense yellow color. Optimal storage conditions are within the amorphous region at 25 °C, aw 0.437, and a water content of 1.98 g H2O per g of dry powder. Strict moisture control is required at higher storage temperatures (up to 50 °C) to prevent microstructural changes. This research enhances understanding of maltodextrin behavior across diverse dextrose equivalents, aiding the development of stable microencapsulated products.