Physicochemical and functional characterization of agave fructans modified by cationization and carboxymethylation

Abstract

This work describes the cationization and carboxymethylation of agave fructans and their physicochemical and functional characterization. The results show that the modification gives rise to degrees of substitution of 0.487 and 0.133 for the carboxymethylated and cationic derivatives, respectively. FTIR, DSC and HPLC-SEC results demonstrated the incorporation of quaternary ammonium and carboxymethyl groups in the native fructan molecular structure. As a result of the structure modification, the increase in molecular weight, the appearance of new bands in the FTIR spectrum and changes in thermal properties were observed. The zeta potential demonstrated the anionic and cationic character of the modified fructans. There were no changes in the swelling capacity, however the cationic fructans have a higher oil holding capacity. Native and modified fructans exhibited antimicrobial effect against Staphylococcus aureus, Listeria monocytogenes, Escherichia coli, and Salmonella enterica Typhimurium with higher antimicrobial activity against Gram negative microorganisms.