What Are Polyphenols in Olive Oil?

Jul 7

2 min read

Updated: 3 days ago

Polyphenols are natural plant compounds found in olives and in fresh extra virgin olive oil. They give good olive oil its bitterness and peppery finish, and they help protect the oil itself from going stale.

The main polyphenols in olive oil

Hydroxytyrosol and tyrosol: the compounds named in the approved health claim
Oleuropein: responsible for much of the bitterness of green olives
Oleocanthal: responsible for the peppery catch at the back of the throat

How polyphenols are measured

Polyphenol content is measured in a laboratory and given in milligrams per kilogram (mg/kg). Levels vary enormously between oils. Our Early Harvest contains over 500 mg/kg and our Master Miller over 400 mg/kg.

What affects polyphenol levels

Harvest timing: olives picked early and green give oil richer in polyphenols
Olive variety: Picual and Cornicabra are naturally high in polyphenols
Speed of milling: the sooner olives are milled after picking, the more polyphenols the oil keeps
Processing: refining removes most of them, so only extra virgin oil keeps them
Age and storage: levels fall over time, and faster with heat and light

The approved health claim

In the UK, one health claim is approved for olive oil polyphenols: they contribute to the protection of blood lipids from oxidative stress. It only applies to oils containing at least 5mg of hydroxytyrosol and its derivatives per 20g of oil, with the benefit coming from a daily intake of 20g.

How to taste polyphenols

A polyphenol-rich oil tastes bitter on the tongue and peppery at the back of the throat, sometimes enough to make you cough. If an oil tastes flat and greasy, it's likely low in polyphenols.

Frequently asked questions