Formation of crystalline complexes between amylomaize dextrin and ceramide

Complexes between amylomaize dextrin (average DP 311) and ceramide were prepared by using two different blending systems: an aqueous batch system containing ethanol and a two-phase system of isopropyl ether and water. The organic solvents and complex formation temperature (50–90 °C) were important in determining the level of complex formation and its crystalline structure. Under X-ray diffraction analysis, the solvents as well as ceramide could form complexes with dextrin as weak V6I type crystals. However, the crystallinity of complexes was much higher in the presence of ceramide, which would enhance complex formation by forming ternary co-inclusion complexes of dextrin–solvent–ceramide. Compared to the two-phase system, the batch system yielded much higher crystallinity of complexes. With a minor use of ethanol (0.5 mL) in the batch system, aqueous blending of dextrin and ceramide at 50 °C for 2 days followed by a storage at 25 °C for 1 day produced well-defined V6I crystal particles as precipitates. The isolated particles had rectangular shapes with a size of 1 μm or less, and contained about half of the ceramide initially added. The ceramide–dextrin complex exhibited enhanced water dispersibility, up to 45% based on the ceramide content in complex.