Encapsulation of gibberellic acid by hydrophobic modified starch for accelerating growth of plants

Abstract

The objective of this research is to encapsulate of gibberellic acid (GA3) by hydrophobic modified starch (HB-Starch). It was prepared by octadecyl bromide conjugation. The HB part was able to perform self-assembled nano micelles which used in agricultural applications for the controlled release. The molecular structure, surface morphology and particle size were characterized by 1H-NMR, FTIR, SEM and zetasizer analysis techniques. Evidently, the degree of octadecyl chain substitution was 8.5 % calculated by 1H-NMR. The evidences illustrated that the octadecyl chain was successfully conjugated on the starch backbone and provided the hydrophobic properties. Additionally, the CMC value of micelle was 0.25 µg/mL determined by fluorescence technique. Furthermore, 1% (w/w) of GA3-HB-Starch produced high entrapment efficiency as well as prolonged the release than the pure GA3, which this led to an increase of plant growth acceleration at the optimum concentration (0.5 ppm).