Preparation Process Optimization and Performance Research of Lemon Juice Nano Silver Antimicrobial Composite Membrane

In this study, antibacterial PVA-SS-LJ-AgNPs composite films were made by using polyvinyl alcohol (PVA) and soluble starch (SS) as ingredients, glycerol as plasticizer, and lemon juice (LJ) as reducing agent to in situ reduced AgNPs from AgNO₃. After single factor and orthogonal experiments, the optimum films preparation process was PVA 3 g, SS 0.5 g, glycerol 3 g, LJ 7 mL, AgNO₃ 130 mmol/L. Under the optimal process, the tensile strength, elongation at break, water vapor permeability coefficient, moisture absorption rate, and light transmittance of the membrane were 12.16 MPa, 1111.59%, 0.09 g/0.01 h·m², 12.56%, 48.05%, respectively. Through the analysis of physical properties and structure of the films, lemon juice could successfully restore AgNPs in situ to films. Compared with the PVA-SS films, the tensile strength and elongation at break of the composite films were improved up to 11.51 MPa and 1470.20%, respectively. Compared with PVA-SS-LJ films, the water vapor penetration and moisture absorption were effectively balanced, AgNPs evenly dispersed in the composite films, the compound films had good inhibition effect for E. coli, Salmonella, Bacillus subtilis, S. aureus, P. aeruginosa. In summary, PVA-SS-LJ-AgNPs composite films met the current new requirements of food packaging materials, and had its potential application prospects.