Sustainable Starch-Based Biofilms Incorporated with Waste Hibiscus Flower Extract for Food-Packaging Applications

Abstract The rapid increase in global demand for plastics has raised serious environmental and health concerns due to their nonbiodegradability and greenhouse gas (GHG) emissions. As a result, to mitigate these issues associated with traditional plastics, bioplastics emerge as a sustainable and promising solution. Therefore, the present study aims to develop starch-based bioplastic films incorporated with wasteHibiscus rosa-sinensis (China rose) flower extract (HFE) for sustainable food-packaging applications. The biofilm was fabricated using a combination of cornstarch, refined flour, citric acid, vinegar, and formaldehyde, with varying proportions of HFE, using the aqueous casting technique (Hb1, Hb2, Hb3, S). The results revealed that the biofilm HB1 exhibited moderate transparency, the highest TS (10.865 MPa), EB (14.57%), moderate YM (74.58 MPa), and a low MC (6.53%). The solubility tests revealed that the biofilms were stable in aqueous, acidic, basic, and alcoholic medium. FTIR analysis confirmed the presence of C–O, C═O, C–H, and a strong O–H peak, and WCA revealed moderate hydrophobicity. Finally, the degradation studies revealed that biofilm HB1 is more degradable. Further, the migration tests confirmed limited transfer of biofilm constituents into food simulants, indicating relatively low overall migration under the experimental conditions investigated. The incorporation of HFE into starch-based bioplastics serves as a bioactive additive, enhancing the physicochemical and functional properties of the biofilms by improving intermolecular interactions. This demonstrates their potential as sustainable alternatives to conventional petroleum-based plastics.