Phenolic compounds and contaminants in olive oil and pomace-A narrative review of their biological and toxic effects

Olive oil is considered one of the main ingredients of the Mediterranean diet, with daily consumption of 25-50 mL per capita. The production of olive oil produces a solid residue, olive pomace. Both olive oil and pomace are products rich in phenolic compounds, and these bioactive compounds are most likely involved in their bio-activities. The most representative phenolic compounds in olive oil and olive pomace are oleuropein, tyrosol, and hydroxytyrosol, which may contribute to the prevention and control of several diseases, from cardiovascular diseases to cancer and neurodegenerative diseases. On the other hand, olives and their derivatives are constantly exposed to contaminants such as mycotoxins, pesticide residues, and polycyclic aromatic hydrocarbons. Phenolic compounds from olive oil and olive pomace could reduce the toxicity of contaminants in these products. On the other hand, the pollutants in olive oil and olive pomace may also affect the beneficial properties attributed to these products. This review summarized current knowledge on the content of phenolic compounds in olive pomace and oil and their biological effects. In addition, it also discussed the beneficial effects of phenolic compounds on toxic compounds in olive products. In addition, it highlighted the importance of conducting further studies to understand the interactions between bioactive and toxic compounds in olive oil and olive pomace to determine these products' actual health benefits.