High hydrostatic pressure enhances the formation of oleocanthal and oleacein in 'Arbequina' olive fruit.

During olive oil production, the activity of endogenous enzymes plays a crucial role in determining the oil's phenolic composition. β-Glucosidase contributes to the formation of secoiridoids, while polyphenol oxidase (PPO) and peroxidase (POX) are involved in their oxidation. This study investigated whether high hydrostatic pressure (HHP), known to cause cell disruption and modify enzymatic activity and food texture, could reduce PPO and POX activity. HHP was applied to 'Arbequina' olives at different settings (300 and 600 MPa, 3 and 6 min) before olive oil extraction. The tested HHP conditions were not effective in reducing the activity of PPO and POX in olives, resulting in oils with a lower phenolic content. However, HHP increased the secoiridoid content of olives, particularly oleocanthal and oleacein (>50%). The pigments in oils produced from HHP-treated olives were higher compared to the control, whereas squalene and α-tocopherol levels and the fatty acid profile remained the same.