Technological and sensory feasibility of incorporating oregano essential oil-loaded nanoemulsions as antioxidants in chicken pâté

Nanoemulsions encapsulating oregano essential oil (OEO) were obtained using phase inversion temperature (PIT), and their antioxidant action was evaluated in vitro and after incorporating spreadable chicken pâté. Nanoemulsions containing 3.25 g of OEO/100 g of presented droplet sizes around 25 nm were highly stable for 90 days of storage under refrigeration. The minimum inhibitory concentration values (1.30 and 1.73 mg OEO/mL for Staphylococcus aureus and Escherichia coli, respectively) and minimum bacterial concentration (3.67 and 3.46 mg OEO/mL for S. aureus and E. coli, respectively) indicated a high antibacterial potential of nanoemulsions in vitro. Regarding in vitro antioxidant activity, 2,2-diphenyl-1-picrylhydrazyl reduction capacity (63.4%) and total phenolics (11 mg equivalent gallic acid/mL nanoemulsion) remained stable following 13 weeks of storage. The evaluation of lipid oxidation in chicken pâté revealed a higher antioxidant action of nanoemulsions than for the nonemulsified OEO and synthetic antioxidant butylated hydroxytoluene. Sensory evaluation data indicated no significant changes in color, odor, and overall acceptability of chicken pâtés incorporated with OEO-loaded nanoemulsions after 90 days of storage. These results revealed that OEO-loaded nanoemulsions obtained using the PIT method are promising in terms of replacing common antioxidants used in this meat product.