Fabrication of corn starch-based composite films functionalized by Rosa roxburghii Tratt fruit pomace via extrusion...

In this study, various levels (0 %-30 % w/w, based on corn starch) of Rosa roxburghii Tratt fruit pomace (RRTP) were used as antioxidant fillers to develop corn starch (CS)-based bioactive films via the extrusion compression molding technique. The results showed that incorporating RRTP into CS could remarkably improve the barrier, mechanical and antioxidant properties of the films compared to pure CS film. In particular, the composite film containing 30 % RRTP had the lowest water vapor permeability and oxygen permeability of 2.94 × 10^-10 g·m·m^-2·s^-1·Pa^-1 and 0.87 × 10^-14 kg·m·m^-2·s^-1·Pa^-1, respectively, together with the highest tensile strength of 3.41 MPa and the strongest DPPH scavenging activity of 88.59 %. LCMS analysis confirmed that RRTP contained many phenolic compounds, which conferred high antioxidant activity to the composite films. Additionally, FTIR analyses demonstrated the formation of hydrogen bonds between CS and RRTP, along with good compatibility as confirmed by XRD and SEM. More importantly, the mushrooms packaged in the CS/30%RRTP film maintained optimal appearance and freshness after 12 days at 4 °C, demonstrating the promising role as antioxidant active packaging for food, following new trends for functional packaging.