Development of an infusion method for encapsulating ascorbyl palmitate in V-type granular cold-water swelling starch

Certain lipophilic components can be inserted very efficiently as guest molecule in the existing single helical amylose cavities in V_H-type crystalline granular cold-water swelling starch (GCWSS). In the present study, ascorbyl palmitate (AscP) was used as a model guest compound. The impacts of temperature (20 and 60°C) and ethanol [48 and 68% (v/v)] and AscP [1.0, 2.5, 5.0, 10.0% (w/w)] concentrations on encapsulation performance were investigated. First, native maize and potato starches were converted into V_H-type GCWSS by aqueous ethanol [48% (v/v)] treatment at 95°C. Exposing GCWSS to AscP induced the formation of inclusion complexes when a particular solvent (and temperature) environment was met. In 48% (v/v) ethanol, raising the treatment temperature to 60°C did not significantly impact on the encapsulation performance. Maximum degrees of AscP encapsulation were 2.9 and 1.5% (w/w) for maize and potato starch, respectively, as determined by proton nuclear magnetic resonance measurements. As maize GCWSS contained more 'parent' V_H-type crystals, it was capable of entrapping more AscP than potato GCWSS.