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Ultrasonication-assisted solution casting was used to prepare polyvinyl alcohol (PVA)/sodium carboxymethyl cellulose (CMC)/nano-ZnO/multilayer graphene nanoplatelet (xGnP) composite films; the performances (mechanical properties, water vapor permeability (WVP), biodegradability and antibacterial activity) of these films were investigated as a function of the ZnO NPs:xGnP mass ratio and ultrasonication time. Intermolecular interactions among ZnO NPs, xGnP and the PVA/CMC matrix were shown to improve WVP, while X-ray diffraction and scanning electron microscopy analyses revealed that the internal reticular structure of ultrasound-treated PVA/CMC/ZnO NPs/xGnP composite films was in a fluffier state than that of the untreated composite films and the PVA/CMC film. The incorporation of ZnO NPs and xGnP into the composite film reduced its tensile strength and elongation at break, and increased antibacterial activity and biodegradability. In addition, we carried out the experiment of strawberry preservation and measured weight loss ratio, firmness, content of total soluble solids and titration acid. Finally, the composite film of 7:3 had the best preservation effect on strawberries. Thus, the obtained results paved the way to develop novel biodegradable composite films with antimicrobial activity for a wide range of applications. [ABSTRACT FROM AUTHOR]

• Edible films werre prepared by embedded L. lactis in corn starch and carboxymethyl cellulose. • The addition of L. lactis improved the barrier properties of the films. • The films showed an effective antimicrobial activity after 30 days. • The films with a 1.5 % L. lactis can release 3.35 mg/mL nisin. • Antibacterial corn starch/carboxymethylcellulose/ L. lactis films with excellent physical properties. In this study, Lactococcus lactis was embedded in a film of corn starch (NS) and carboxymethyl cellulose (CMC) prepared using a casting method. At a CMC:NS ratio of 5:5, the composite film had the best comprehensive properties. Scanning electron microscopy images clearly showed that L. lactis was effectively embedded. The film with 1.5 % L. lactis showed the best performance and the lowest water vapor transmission rate (5.54 × 10−11 g/m s Pa. In addition, the edible film retained a viable count of 5.64 log CFU/g of L. lactis when stored at 4 °C for 30 days. The composite film with 1.5 % L. lactis showed the highest release of nisin (3.35 mg/mL) and good antibacterial activity against Staphylococcus aureus (53.53 %) after 8 days. Therefore, this edible film is a viable alternative antimicrobial strategy for the active packaging of foods containing low moisture content. [ABSTRACT FROM AUTHOR]

• Two lactic acid bacteria (LAB) strains with high exopolysaccharide yield were selected from a pickled water. • Edible films based on cassava starch were developed containing LAB, and sodium carboxymethylcellulose (CMC). • The antioxidant activity of the composite films was significantly enhanced. • Lactobacillus plantarum showed uniform distribution in the cassava starch/CMC matrix. • The composite films can extend the shelf life of banana. In this study, two different species of lactic acid bacteria (LAB) (Lactobacillus plantarum and Pedocococcus pentosaceus) with high exopolysaccharide (EPS) yield were selected from a pickled water. Further, edible films based on cassava starch (CS) were developed containing LAB, and sodium carboxymethylcellulose (CMC). After addition of probiotics, the antioxidant activity of the composite film was significantly enhanced. Further, as the probiotic content increased, the antioxidant activity continuously increased. Moreover, L. plantarum showed uniform distribution in the CS/CMC matrix, forming a denser structure, which effectively blocked the penetration of water molecules and exhibited ultraviolet protection. Finally, due to the intermolecular interaction between probiotics and the CS/CMC matrix, the water vapor and light transmission rates were reduced, effectively blocking water and light to prevent lipid oxidation deterioration in food packaging. Banana shelf life has qualitatively improved with 2% LAB added composite film and its application in food packaging has been affirmed. [ABSTRACT FROM AUTHOR]