Fortification of sugar-free chewing gum with Eucalyptus globulus leaves phenolic extract: Effects on quality characteristics and shelf life

Large amounts of Eucalyptus globulus leaves (EL) are generated during wood processing, remaining underutilized despite their potential health benefits related to their high levels of bioactive compounds. In this study, three EL samples from different regions of Tunisia ; Haouaria, Makther, and Haffouz, were analyzed for their phenolic composition and antioxidant activities. EL from Haouaria contained the highest levels of phenolic compounds, with rutin, benzoic acid and chlorogenic acid being the major identified compounds. Possessing the highest antioxidant content and potential, the Haouaria EL phenolic extract was incorporated into chewing gum at two concentrations, 0.05 and 0.1%. The sensory quality and shelf life of the developed chewing gum were evaluated using accelerated shelf life testing at temperatures of 25, 35, and 50°C, based on the Arrhenius equation. Sensory analysis revealed that the chewing gum samples containing 0.05% extract from Haouaria were more resistant to sensorial quality deterioration during storage. Furthermore, the Arrhenius model, applied for the first time to model the degradation of the gum's moisture and hardness, effectively predicted the shelf life of the chewing gum. Based on the hardness parameter at 25°C, the shelf life of the gum samples was 19.69 months, which was closest to the control samples (20.70 months) that used synthetic antioxidants. These results highlight the potential of EL phenolic extract as a natural food preservative, offering a viable alternative to synthetic antioxidants.