Bioactivity of Aromatic Plant Hydrolates and Application for Pork Marination

Abstract

The study evaluated the potential of Thymus mastichina, Lavandula luisiery, and Origanum virens hydrolates—essential oil-rich species found in the Dehesa ecosystem—as natural agents for pork preservation through marination. Hydrolates, the main by-products of essential oil distillation, were characterized by their volatile composition, total phenolic content, antioxidant capacity, and antimicrobial activity against Escherichia coli and Listeria innocua. Pork fillets were marinated (24 h) with increasing hydrolate concentrations (1:1, 1:1.5, 1:2 w/w) and then stored for eight days under refrigeration to assess microbial growth, oxidation, and color changes. All hydrolates exhibited similar antimicrobial effects, though Origanum showed the highest phenolic content and antioxidant activity. Marination had limited antimicrobial impact. Marination with Origanum and Thymus provided significant protection against lipid oxidation during storage, while Lavandula displayed limited or even pro-oxidative behavior at certain doses. Marination did not affect carbonyl formation although it caused slight changes in instrumental color. Overall, the study highlights the potential of Lavandula, Thymus, and Origanum hydrolates as sustainable alternatives to synthetic antioxidants in meat products, emphasizing their antioxidant—rather than antimicrobial—effect.