Antimicrobial, microscopic and spectroscopic properties of cellulose paper coated with chitosan sol-gel solution formulated by epsilon-poly-L-lysine and its application in active food packaging

Cellulose paper-chitosan (CC) double-layer films containing epsilon-poly-L-lysine (epsilon-PL) (0.5 and 1% w/v) were developed. FTIR analysis showed a strong association between the epsilon-PL and CC film. Antimicrobial activity against Listeria monocytogenes was investigated both in vitro and in the chicken breast meat. The CC films without epsilon-PL showed no antimicrobial activity, while the addition of epsilon-PL induced significant (p < 0.05) effects. During the 28 days of storage at 4 degrees C, no significant difference was found on the anti-listeria activity of films. When storage temperature was raised from 4 to 22 degrees C, the antimicrobial activity was reduced. Films containing 1% epsilon-PL exhibited 1.5 log io CFU/g reduction in L. monocytogenes population during 12 days storage of meat at 4 degrees C, while no significant reduction was found in CC films with 0.5% epsilon-PL (p > 0.05). This study revealed an antimicrobial activity for CC films impregnated with epsilon-PL, to control foodborne pathogens in meat.