Antimicrobial effects of pulsed light activated TiO-Polylactic acid film.

A study was conducted to evaluate the antimicrobial effect of TiO incorporated polylactic acid (PLA) films, activated by pulsed light (PL). TiO-PLA films with 0, 0.5, 5, 10, and 20 % TiO/PLA ratio were developed by the solvent casting method. Populations of and on film surfaces were determined after the films were PL-treated in three ways: PL treatment on the inoculated film surface; PL treatment from the reverse side of the inoculated film surface; PL treatment before the inoculation on the film surface. A 5 s PL treatment reduced populations on PLA film from 6.2 to 2.5 log CFU/cm and on TiO-PLA film from 6.2 to 1.1 log CFU/cm, indicating the combined antibacterial effect of PL and TiO Light-activated TiO-PLA films maintained antibacterial activity against and for 2 h after the 5 s PL treatment, as the activated TiO-PLA films were still able to reduce bacterial populations by up to 2.5 log CFU/cm. These findings suggest that pre-activated TiO-PLA films have potential for packaging foods that are sensitive to UV light.