Thermal, chemical, and biological characterization of a bioactive zirconia material embedded with orange peel extract

Abstract Although the development of active packaging with plastics has been the subject of numerous studies, glass-based active packaging is a more environmentally friendly option with benefits like durability, recyclability, and a smaller environmental impact. This research evaluates the development via sol–gel method of zirconia/orange peel extract (ZrO 2 /OP8, 25, 33 and 50%) hybrid materials as suitable smart food and beverage packaging able to release bioactive compounds. The hybrids are characterized by Fourier transform infrared (FTIR) spectroscopy, differential scanning calorimetry (DSC), thermogravimetric analysis (TG), antimicrobial and cytotoxicity analyses, an in vitro release study. FTIR revealed the presence of both the organic and inorganic phases in the hybrids. Moreover, DSC and TG suggested that the hybrids are stable up to 300 °C with a main mass loss related to dehydration water. Moreover, the presence of FTIR bands of organic residues on ZrO 2 /OP25% sample after heat treatment up to 800 °C revealed that ZrO 2 /OP25% was the highest stable percentage of extract entrapped into the hybrid. Furthermore, this hybrid was the one able to release the higher amount of extract with respect to its theoretical amount and showed no cytotoxicity. Finally, the antimicrobial analysis showed that an increase in OP extract % leads to an increase in antimicrobial properties against the Gram-positive bacteria. Based on this findings, additional research could fully evaluate the material functionality under real-world situations and enhance its features. Graphical abstract