Development of Biodegradable Films with Antioxidant Activity Using Pectin Extracted from Cissampelos pareira Leaves

In this study, pectin was extracted from Cissampelos pareira (Krueo Ma Noy) leaves by facile, green extraction at room temperature. The C. pareira pectin structure was confirmed by FTIR spectroscopy and the pectin had an intrinsic viscosity of 6.1 dL/g. The extracted C. pareira leaf pectin was used to prepare pectin/polyvinyl alcohol (PVA) films that were crosslinked with 0–64 wt% succinic acid (SA), and the films were compared for their mechanical, antioxidant, and potential biodegradability properties. Incorporation of SA produced thicker pectin/PVA films with a higher surface hydrophobicity. The pectin/PVA film without SA (PEC–PVA) was crosslinked as confirmed with FTIR spectroscopy, which was improved by addition of SA. Addition of large amounts of SA, however, resulted in phase separation, which reduced visible light transparency and mechanical properties. The film containing 16% SA (PEC–PVA–16SA) had the highest tensile strength of 9.4 MPa and Young’s modulus of 53.4 MPa. All films showed antioxidant release via DPPH scavenging activity, which was enhanced in food simulants with higher ethanol concentrations (10, 30, and 50% w/w). The film PEC–PVA–16SA had the highest DPPH scavenging activity of 84% in 50% w/w ethanol. Upon soil burial, all films showed more than 50% weight loss within 7 days, which gradually increased up to 28 days soil burial. The FTIR spectra after soil burial confirmed that pectin and SA were removed from the films whereas PVA remained. These results suggest that pectin/PVA films prepared from C. pareira leaf pectin can be used as biodegradable food packaging with antioxidant properties.