Preparation and Properties of Starch-Based Antibacterial Film with Orange Essential Oil Emulsified by Cellulose Nanocrystalline

Abstract

Using corn starch (CS) as the film substrate, citric acid as the crosslinking agent, and Pickering emulsion prepared with cellulose nanocrystals (CNC)-emulsified orange peel essential oil (OPO) as the antibacterial agent, an antibacterial composite film (CS/CNC-OPO) was successfully prepared by the casting method. The effects of different contents of CNC and OPO on the mechanical strength, water vapor transmission rate, water contact angle and antibacterial properties of the composite film were analyzed, and the composite film was characterized by Fourier transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD) spectroscopy and scanning electron microscopy (SEM). The results showed that the performance of the CS/CNC-OPO antibacterial film was the best when 11% OPO was added and the CNC-to-OPO ratio was 1:11 (g/mL). The antibacterial film had the following properties: water vapor permeability, 1.03 × 10-3 g/(m·h·kPa); water contact angle, 74.53°; and tensile strength 6.01 MPa. The area of inhibition zone of the film against Escherichia coli and Staphylococcus aureus was up to 88.4 and 96.45 mm2, respectively. Therefore, the starch-based film has good strength, hydrophobic and antibacterial properties, and has broad application prospects in the field of food packaging.

Keywords

• starch-based antibacterial film; cellulose nanocrystalline; essential oil; food packaging