Development and Characterization of Novel Bio‐Based Films Based on Sodium Alginate and Pineapple Crown Waste: Effects of Emulsion Integration and Matrix Formulation

The ubiquitous application of conventional petroleum‐derived polymers has precipitated a severe global environmental crisis, driving the urgent need for bio‐based alternatives. To address this challenge, novel biopolymeric films were developed utilizing a crosslinked sodium alginate matrix reinforced with upcycled pineapple crown waste and structurally modified by a Tween 20‐stabilized coconut oil emulsion. The composite films were fabricated via the conventional solvent casting technique, and their formulation was systematically optimized using a Central Composite Rotatable Design (CCRD). Experimental analysis revealed that the optimal formulation, characterized by a restricted glycerol concentration and the inclusion of the lipidic emulsion, exhibited significantly reduced water solubility and moisture retention. The incorporation of the lipid domains within the biopolymer network, as suggested by structural and morphological observations, mitigated the inherent hydrophilicity of the matrix, yielding a more compact and seemingly homogeneous microarchitecture. Furthermore, the formulation containing the stabilized lipidic phase exhibited enhanced high‐temperature stability and degradation resistance, which may be associated with a potential thermal shielding effect and altered char formation. Ultimately, these emulsion‐stabilized biocomposites present a promising bio‐based alternative for the packaging industry, with potential applications in the circular bioeconomy through the valorization of agricultural waste.