Preparation of N-vanillyl chitosan and 4-hydroxybenzyl chitosan and their physico-mechanical, optical, barrier, and antimicrobial properties

► Chitosan was chemically modified with vanillin and 4-hydroxy benzaldehyde with a degree substitution of 63% and 59%, respectively of the amino group. ► WVTR decreased by 68% in N-vanillyl chitosan and 79.59% in 4-hydroxybenzyl chitosan, respectively. ► Tensile strength improved by 17.7% in N-vanillyl chitosan and 11.11% in 4-hydroxybenzyl chitosan. ► N-vanillyl chitosan and 4-hydroxybenzyl chitosan film discs showed a marked reduction of aflatoxins produced by the fungus to 98.9% and at non-detectable levels, respectively.