Preparation and characterization of a quaternary ammonium derivative of pectin

Cationic derivatives of pectin were prepared by reacting pectin with 3-chloro-2-hydroxypropyltrimethylammonium chloride (CHPTAC) in presence of sodium hydroxide (NaOH). The chemical structures of derivative were characterized by using elemental analysis, FT-IR, and 13C NMR spectroscopy. The results revealed that the degree of substitution (DS) of quaternized pectin (QP) could be controlled by adjusting the molar ratio of CHPTAC to pectin, the molar ratio of NaOH to CHPTAC and reaction temperature occurred during quaternization. The moisture absorption (Ra) and moisture retention (Rh) abilities of QP are closely related to the DS value. With the DS value increasing, Ra and Rh increased. In vitro antimicrobial activity assessment exhibited QP showed pronounced inhibitory effect against the three bacteria (Staphylococcus aureus, Escherichia coli, and Bacillus subtilis). The improved functionalities of the derivative might be explained by its polycationic characteristics.