Engineering Biodegradable Sodium Alginate Films with Dragon Fruit Peel Powder and MgO Nanoparticles

Abstract

This study investigated the effect of the addition of dragon fruit peel powder (DFP) and MgO nanoparticles on sodium alginate (SA) films. The control film (S1 film), DFP-enriched (S2 film), MgO nanoparticles-enhanced (S3 film), and a film combining both MgO nanoparticles and DFP (S4 film) were evaluated. The tensile strength increased by 252.43, 290.27, and 645.13% for the S2, S3 and S4 films, respectively. These enhancements were accompanied by a marked improvement in the UV-blocking property, thermal stability, antioxidant activity,2,2′-azino-bis-3-ethylbenzothiazoline-6-sulfonic acid (ABTS) radical scavenging activity, opacity and thickness. The water vapor permeability and transparency were decreased to 3.45 × 10−10 g−1 Pa−1 S−1 and 1.82% for the S4 film. An environmental scanning electron microscope (ESEM) study revealed a notable increase in surface roughness with the incorporation of DFP. X-ray diffraction (XRD) analysis indicated that the MgO nanoparticles possessed a crystallographic structure that was compatible with the SA film matrix, with the S4 films exhibiting the highest crystallinity index (28.92%). The overall migration study showed that all SA films complied with the overall migration limit of 60 mg/kg of simulant for fatty food simulants. The biodegradability test revealed complete degradation of the S1, S3, and S4 films before 20 days while the S2 film exhibited a substantial mass loss of 84.99% within the same 20-day timeframe.