Poly(vinyl alcohol) antibacterial films containing cross-linked chitosan-citric and photosensitive curcumin

Composite films PVA-CS-Cur(x) (x = 0, 0.01, 0.06 and 0.12%) were successfully obtained by using vacuum-drying at 80 degrees C. The occurrence of nonenzymatic browning and cross-linking of chitosan-citric improved the thermal stability, water-resistance, and mechanical property of films. Under the same humidity, the oxygen permeability of PVA-CS-Cur(x) showed the dependence of test temperature and curcumin concentration (P < 0.05). Relative to other films, the oxygen permeability (10(-14) cc mu m cm(-2) s(-1) Pa-1) of PVA-CS-Cur(0.12) was 3.47 +/- 0.55, 4.72 +/- 0.94, and 7.29 +/- 0.45 at 23, 30, and 40 degrees C, respectively, showing gentle upward trend as temperature increased. Under white light irradiation, excellent antibacterial capability of PVA-CS-Cur(x) demonstrated that polycationic chitosan-citric complex and curcumin immobilized in films played the roles as synergistic antibacterial agents. Upon white irradiation of 20 min at 60 mW cm(-2), the bactericidal rate of PVA-CS-Cur(0.12) reached to 94.0 +/- 3.09%. The excellent decontamination in meat preservation endowed films with the possibility in application of food decontamination.