Study on the property of mesoporous silica nanoparticles loaded with nisin for poly (lactic acid)-based packaging film

Nisin was loaded in mesoporous silica nanoparticles (MSN) (0, 1, 2 and 3 wt%) and incorporated into poly (lactic acid) (PLA) matrix by casting method. The mechanical property, water vapor permeability, thermal property, and antimicrobial property of PLA nanocomposite films were measured. And the internal structure of the composite film was observed through the Scanning electron microscope. Meanwhile, the kinetic of nisin releasing from food simulated solution was investigated and the migration model was established. The result showed that mesoporous silica had an effect on the mechanical and thermal property of the composite films. Both water vapor transmission rate (WVP) and oxygen permeation rate (OTR) decreased, especially for 3MSN/NI/PLA, where WVP decreased by about 9.64% and OTR decreased by 35.19%, which was beneficial to improve the preservation effect. With the addition of MSN, the amount of loaded nisin increased, and at 3MSN/NI, the nisin loading reached 88.75%, and the mesoporous silica could effectively control the release of nisin, thus prolonging the preservation effect. The release kinetic of nisin was described by Fick's law and Weibull's model. In short, the PLA nanocomposite film has the potential to be used as an antimicrobial active film by adding nisin as an antimicrobial agent.