CO inclusion complexes of Granular V-type crystalline starch: Structure and release kinetics.

Granular V-type crystalline starch (V-type starch) was prepared using different starch varieties by alcoholic-alkaline treatment. Carbon dioxide was encapsulated into V-type starch using a solid encapsulation method. The morphological and structural properties of the inclusion complexes (ICs) were characterised using scanning electron microscopy and X-ray diffraction. Fourier-transform infrared spectroscopy and C Nuclear Magnetic Resonance proved that CO was successfully encapsulated. The encapsulation capacity of V-type starches was determined by head space gas chromatography, and ICs made from normal maize starch achieved the highest CO concentration (2.55%, w/w). The controlled release characteristics of ICs were also determined at various temperatures and relative humidity, and ICs made from normal potato starch exhibited slower release characteristics. The release kinetics showed that the release of CO from ICs was accelerated by increasing temperature or RH. V-type starch is a renewable, inexpensive material for encapsulation of gasses such as CO.