Bioengineering of Pickering emulsion integrated pH-responsive gelatin film: Mechanistic insights into controlled release and safety assessment for duck meat

Abstract

Controlled release of active components consistent with meat preservation should be considered while designing bioactive packaging film to ensure meat quality and safety. Hence, the study focused on the nano-reinforcement of gelatin film with black pepper essential oil (BPEO) Pickering emulsion stabilized with a biopolymeric complex of bacterial cellulose nanocrystal (BCNC) and the novel nanochitosan (nCS). The charge characteristics, structure, and stability of the Pickering emulsion were studied. Physicochemical, mechanical, structural properties, and bioactivity of the biocomposite films were thoroughly characterized. The findings demonstrated that the BCNC/nCS complexes exhibited strong molecular interactions, enhanced crystallinity, and reduced zeta potential, supported by strong electrostatic interactions and hydrogen bonding. Specifically, the Pickering emulsion stabilized with BCNC-nCS (4:1) exhibited superior emulsion stability with a negligible creaming index and minimal increase in particle size, polydispersity index, and zeta potential during one-month refrigeration. Meanwhile, the bioactivity of the emulsion was governed by nanochitosan concentration, demonstrating greater effectiveness against S. aureus. Furthermore, gelatin-based films loaded with 0.5 %, 1 %, and 2 % of BPEO as Pickering emulsion, and the film containing 1 % BPEO showed the strongest molecular interaction and higher crystallinity (78.17 % CrI), with significant impact on incorporation efficiency (51.61 ± 3.28 %), hydrophobicity (120.56°±1.86), and bioactivity of film. Consequently, these packaging films revealed pH-responsive controlled-release properties and effectively preserved duck meat with a 2.26 log reduction compared to the control over 10 days of refrigeration. This research underscores the potential of biopolymeric films with pH-responsive properties, presenting a sustainable solution in meat packaging.