Effects of argon dielectric barrier discharge (DBD) cold plasma treatment on mechanical, barrier and antimicrobial properties of chitosan film

This research studied the effects of argon dielectric barrier discharge (DBD) plasma on properties of chitosan film to be used as active food packaging. The effects of plasma treatment time (0, 30, 60, 90 and 120 s) on tensile strength (TS), elongation at break (EAB), colour, water vapour permeability (WVP), oxygen transmission rate (OTR), contact angle and antimicrobial activity of films were investigated. Depending on the plasma treatment time, the TS values of plasma-treated film increased, but there were no significant differences between the EAB of control and treated films. The formation of the oxygen-containing groups and the occurrence of etching affected the WVP, contact angle, roughness and antimicrobial activity of plasma-treated film. Chitosan film treated with 60 s of DBD plasma had good OTR (<0.05 cc m(-2) day(-1)), hydrophilicity and antimicrobial activity against various kinds of bacteria. However, it may need longer than 60 s of the treatment time to increase the WVP of the films. Overall, these results implied that plasma treatment can be used as an alternative non-thermal approach for improving the characteristics of film packaging.