What Is High-Polyphenol Olive Oil, and Why 687 mg/kg Matters

High-polyphenol olive oil is extra virgin olive oil that's naturally rich in the antioxidant compounds found in olives. There's no official cut-off, but producers usually use the term for oils measuring a few hundred mg/kg or more. Our latest lab test measured 687 mg/kg.

What are polyphenols?

Polyphenols are natural plant compounds. In olive oil they include oleuropein derivatives, hydroxytyrosol and oleocanthal. They do two noticeable things:

• They create flavour. The bitterness on your tongue and the peppery catch in your throat both come from polyphenols.
• They protect the oil. As antioxidants, they slow down oxidation, so the oil stays fresh for longer.

How polyphenols are measured

Labs report polyphenols in milligrams per kilogram of oil (mg/kg). There are two common methods:

• Folin-Ciocalteu measures total polyphenols, expressed as gallic acid equivalent. This is the method used for our oil.
• HPLC separates and measures individual compounds. It's the method required for the EU-approved health claim about olive oil polyphenols.

The two methods give different numbers, so always check which one a producer used before comparing oils.

What affects polyphenol levels?

• Olive variety: robust varieties such as Coratina, Picual and Koroneiki are naturally richer.
• Harvest timing: greener, earlier-harvested olives contain more.
• Milling: fast, cool processing preserves them.
• Age and storage: levels fall over time, faster with heat, light and air.

Why 687 mg/kg matters

Our oil is Coratina-led, Puglia's signature variety, and cold pressed at source. An independent ISO 9001-certified lab measured 687 mg/kg of total polyphenols (Folin-Ciocalteu method) in January 2026. That explains its bold, peppery character, and it's a strong sign of a fresh, well-made oil. See the full lab results.

How to taste the difference

Sip a teaspoon of the oil on its own. If you feel a tickle or a slight urge to cough as it goes down, that's oleocanthal at work. Oils low in polyphenols taste soft, buttery and mild.

Quick answers

Does cooking destroy polyphenols? Some are lost with heat, but extra virgin olive oil keeps much of its antioxidant protection at normal cooking temperatures.

Do polyphenols decline after opening? Yes, gradually. Keep the bottle sealed, cool and dark, and use it within a few months.

Try our single-estate extra virgin olive oil.