Abstract
This research aims to prepare potato starch nanoparticles (SNPs) by hydrochloric acid hydrolysis. The esterification reaction of starch nanoparticles with rosin acid is catalyzed by Maghnite-H
+
as green catalyst, a non-toxic proton exchanged montmorillonite (sheet silicate clay). The influence of synthesis conditions, including reaction temperature, reaction time, and the amount of catalyst, are assessed using a response surface method relying on a central composite design with three factors and three levels. FTIR spectroscopy analysis elucidates the esterification of SNPs with rosin acid, with the appearance of a new intense peak C=O ester at 1726 cm
−1
. Scanning electron microscopy observations reveal some atomic/molecules disorder after esterification. X-ray diffraction analysis indicates the presence of the amorphous structure, with a significant decline of the crystallinity upon esterification of SNPs. Thermogravimetric analysis manifests that the thermal stability of esterified SNPs is lower compared to native starch and SNPs. The antioxidant characteristics of SNPs before and after esterification investigated through 1,1-diphenyl- 2-picryl hydrazyl radical scavenging tests demonstrate a dose-dependent increase in the antioxidant activity that is comparable to standard vitamin C (ascorbic acid).