Preparation and characterization of an antioxidant edible film with soluble soybean polysaccharide and pomelo peel extract and its application in lipid packaging

An antioxidant packaging film was prepared by incorporating soluble soybean polysaccharide (SSPS) and pomelo peel extract (PPE), which possessed antioxidant and enhanced mechanical properties for lipids preservation. The effects of PPE dosage on structural, physical, and antioxygenic performance of the SSPS-PPE films were investigated. Further, the preservation effect of SSPS-5PPE film on lard was also studied. Scanning electron microscopy results indicated that the film stratified with excess PPE (≥0.07 g/g SSPS) remained intact and compact. Hydrogen bonding between SSPS and PPE was shown in the Fourier transform infrared spectra. The incorporating of PPE greatly lessened the light transmittance but enhanced the UV resistance to further optimize the barrier and mechanical properties by reducing the water vapor permeability from 2.79 × 10 to 1.37 × 10 g⋅mm⋅s⋅Pa, lowering the oxygen permeability from 2.69 × 10 to 1.87 × 10 cm⋅s⋅Pa, and improving the tensile strength from 0.38 to 2.39 MPa. The SSPS-PPE film possessed good antioxidant ability, with the scavenging activity of SSPS-7PPE film for DPPH and ABTS were 80.34% and 91.68%, respectively. Packaging experiments suggested SSPS-5PPE film could extend the shelf life of lard by approximately 25 d at 20 °C. In brief, the PPE-incorporated SSPS film can be used in packaging to extend the shelf life of lipids.