Influence of glucan structure on the swelling and leaching properties of starch microparticles

Microparticles were made by a water-in-oil emulsion technique from acid-hydrolyzed and debranched normal, waxy and high-amylose corn starches. The starches prepared had a weight-average molecular weight (Mw) ranging 3.6 × 10(7)-2.5 × 10(4), a polydispersity ranging 1.16-9.16, an apparent amylose content ranging 2.84-100%. These microparticles exhibited crystallinity ranging 4.41-22.84%, swelling power ranging 2.45-7.84 and percentage of leaching ranging 1.72-74.91%. Swelling power in water (R(2)=0.86) and percentage of leaching in water (R(2)=0.89) were modeled by a response surface method, using the following parameters: Mw, polydispersity, apparent amylose content and crystallinity of starch in microparticles. Overall, this study showed the key parameters for controlling the behavior of starch microparticles were related to the cohesiveness of the three-dimensional network, particularly through the retrogradation of starch polymers, the formation of crystallites and junctions zones. Such microparticles could be used for designing economical and biocompatible delivery systems of compounds for food, drug, or other applications.