Development of antioxidant-active waste bread bioplastic films incorporating Barleria acuminata extract and extract-mediated copper phosphate nanohybrid for sustainable food packaging

Food-waste valorization provides a sustainable route for developing biodegradable packaging materials while reducing reliance on conventional biopolymer resources. In this study, waste bread was utilized as a starch-rich, pre-gelatinized feedstock to develop bioplastic films, with Barleria acuminata extract (BABP) and a B. acuminata -mediated copper phosphate nanohybrid (NHBP) incorporated to enhance functionality. The films were characterized for physicochemical, mechanical, morphological, elemental, antioxidant, migration, and α-amylase-mediated enzymatic hydrolysis properties. NHBP exhibited the highest tensile strength (3.42 ± 0.20 MPa), compared with BABP (2.16 ± 0.66 MPa) and BP (1.68 ± 0.12 MPa), whereas BABP showed the highest elongation at break (66.40 ± 5.45%). NHBP also exhibited the lowest moisture content (6.13 ± 0.32%) and water solubility (22.67 ± 3.70%), indicating improved water resistance. FESEM revealed compact and relatively homogeneous film structures, while EDX confirmed copper and phosphorus incorporation. BABP demonstrated the highest DPPH radical-scavenging activity (85.61 ± 4.03%), followed by NHBP (67.08 ± 5.83%) and BP (9.70 ± 1.32%). Matrix-corrected migration of Folin–Ciocalteu-reactive compounds was substantially lower from NHBP (1.229 µg/mL) than from BABP (12.951 µg/mL), indicating greater retention of extract-associated compounds. All films underwent α-amylase-mediated hydrolysis, with relative hydrolysis of 100.00 ± 0.92%, 68.11 ± 1.16%, and 65.25 ± 1.39% for BP, BABP, and NHBP, respectively. Overall, the study integrates waste-bread valorization, natural antioxidant functionality, bioactive retention, and organic–inorganic reinforcement in a single sustainable packaging platform. To the best of our knowledge, this is the first report of a Barleria -mediated copper phosphate nanohybrid incorporated into a waste-bread-derived bioplastic matrix.