Single helix in V-type starch carrier determines the encapsulation capacity of ethylene.

Abstract

V-type starch carriers with different single helix contents were prepared using alcoholic-alkaline treatment followed by ethanol precipitation. Ethylene gas was entrapped into V-type starch carriers using a solid encapsulation method. The morphological and structural properties of inclusion complexes (ICs) were characterized using scanning electron and light microscopy, X-ray diffractometry, 13C solid-state nuclear magnetic resonance (NMR) and Raman spectroscopy. Aqueous ethanol treatment resulted in swelling and aggregation of starch granules, and B-type diffraction reflections were either reduced or completely lost with evolution of V-type pattern. Ethylene concentrations in ICs vary from 15.4% to 23.6% (w/w), which was positively correlated with the single helix content in V-type starch carriers. The formation of ICs was confirmed by appearance of the characteristic peak associated with ethylene molecule on the 13C NMR (123.14ppm) and Raman (1630cm-1) spectra. For the first time, we demonstrated that the single helix in V-type starch carrier determines the encapsulation capacity of ethylene.