Hydroxytyrosol (HXT)

Hydroxytyrosol is a phenylethanoid, a type of phenolic phytochemical with antioxidant properties. In nature, hydroxytyrosol is found in olive leaf which is used for medical purposes, with immunostimulant and antibiotic properties. It also exists in olive oil, in the form of its elenolic acid ester oleuropein and, especially after degradation, in its plain form. Oleuropein, along with oleocanthal, are responsible for the bitter taste of extra virgin olive oil. Hydroxytyrosol itself in pure form is a colorless, odourless liquid. The olives, leaves and olive pulp contain large amounts of hydroxytyrosol (compared to olive oil), most of which can be recovered to produce hydroxytyrosol extracts. However, it was found that black olives, such as common canned variety, containing Iron(II) gluconate contained very little of the original hydroxytyrosol as iron salts are catalysts for its oxidation.