Functional Olive Oils Infused with Mediterranean Herbs Enhance Cheese Preservation and Nutritional Profile

The demand for functional foods has driven research into bioactive-enriched dietary products. In this study, olive oil was enriched with phenolic-rich herbs, including oregano, rosemary, basil, and thyme, using an optimized ultrasound-assisted extraction (UAE) process. The resulting infused oils were evaluated for their phenolic content, antioxidant capacity, oxidative stability, and effects on cheese preservation. Rosemary-infused oil exhibited the highest total phenolic content (556.1 mg GAE/kg) and oxidative stability in the Rancimat test (induction time of 82.25 h), while oregano- and basil-infused oils had the strongest DPPH radical scavenging capacity (IC₅₀ of 2.36–2.38 mg/mL). Cheese stored in these plant-infused oils showed reduced lipid oxidation and microbial growth over 21 days. The lowest content of thiobarbituric acid reactive substances (TBARS) was recorded in the cheese immersed in rosemary- and thyme-infused oils (0.53 and 0.66 mg MDA/kg cheese, respectively); whereas the untreated cheese had TBARS value of 2.98 mg MDA/kg cheese. Microbiological analysis revealed a reduction in counts of coliforms and yeasts and molds, particularly in the cheese treated with oregano- and basil-infused oils. These results highlight the potential of bioactive-enriched olive oils as natural preservatives and functional ingredients, extending cheese shelf life while enhancing its nutritional value. This study provides a foundation for developing innovative functional foods that integrate plant-derived antioxidants and antimicrobials into widely consumed products.