Enzyme resistant starch spherulites have the potential to be used as time-release matrices for the delivery of nutrients and active pharmaceutical ingredients to the lower gastrointestinal tract if their enzyme resistance can be predictably controlled. Here, the modification of resistant starch content of spherulites using amylose of varying molecular weight is demonstrated. Starch spherulites made from common corn starch amylose of DP 642 and DP 120 exhibit 24% and 34% B-type crystallinity and 36.6% and 61.7% resistant starch content, respectively. Though fewer in number and with a tendency to clump, spherulites maintain their approximate size, shape, and birefringence after hydrolysis with α-amylase and amyloglucosidase for up to 48 h. Enzyme digestion for 16 h caused a near doubling in dissolution enthalpy of the residue and also in enzyme resistance when the residue is digested for an additional 16 h. Atomic force microscopy reveals that the spherulites comprise a dense periphery with fine structure similar to native starch granules.
All Science Journal Classification (ASJC) codes
- Food Science
- Organic Chemistry