Development of PE-based antibacterial and antioxidant films with L-ascorbic acid-p-hydroxybenzoate addition

In this work, a PE-based antibacterial and antioxidant material was successfully developed. L-Ascorbic acid and p-hydroxybenzoic acid were used as raw materials to synthesize L-ascorbic acid-p-hydroxybenzoate (LPHB) by direct esterification method. LPHB was added to polyvinyl alcohol (PVA) solution and coated on corona-treated low-density polyethylene (LDPE) film coated with primer layer to prepare a composite film. The effects of different concentrations of LPHB on the performance of composite films were investigated to determine the optimal amount of addition, and then to prepare both antibacterial and antioxidant films. The antimicrobial properties of LPHB were analysed. The antibacterial, antioxidant, mechanical, barrier properties and morphology of the films were characterized and analysed. The results showed that the addition of LPHB significantly improved the antibacterial and anti-mould properties, oxidation resistance, and barrier properties of the composite film compared to the LDPE film. The best overall performance of the composite film was achieved when the content of LPHB was 1.5%, the antibacterial rate against Escherichia coli and Staphylococcus aureus reached 99%, and the free radical scavenging rate reached 67.22%. In addition, the cling film added with LPHB has better antioxidant and antibacterial properties, which has obvious effect on bread preservation and has potential for application in food packaging.