You've seen “antioxidants” on every other label. Polyphenols are the specific plant compounds that make extra virgin olive oil interesting as a food. They are also the first thing a slow mill, a late harvest, or a sunny shelf will destroy.
A simple definition
Polyphenols are the plant's defense system — protection against sun, pests, and damage. In olives they concentrate in green fruit and transfer into the oil if you crush it gently, soon after harvest. In people they act as antioxidants and as mild anti-inflammatory agents. The research is not about “olive oil” in the abstract. It is about oil that still has these compounds in it.
Hydroxytyrosol
The compound the European Food Safety Authority named when it allowed a health claim for olive-oil polyphenols: they help protect blood lipids from oxidative stress, provided you get enough hydroxytyrosol and its derivatives in a day.
Oleuropein
The bitterness in a fresh, early oil. It breaks down toward hydroxytyrosol as the oil and the fruit age. Early harvest keeps more of it.
Oleocanthal
The sting. Researchers at the Monell Chemical Senses Center showed it hits the same throat receptor as ibuprofen and inhibits COX enzymes in a similar way. That peppery cough is not a flaw. It is a quality marker. If an oil never bites, it was probably harvested late, refined, or left sitting too long.
Tyrosol
Less famous, still part of the phenolic family that works with hydroxytyrosol on LDL oxidation.
How they are measured
Labs report total polyphenols in milligrams per kilogram, usually by HPLC. That is the right tool. A tasting panel can guess — bitterness and pungency track the chemistry — but a panel is not a certificate.
We will not print a milligram number for Olivyra until an independent lab returns one. This lot is pending. The oil is made the way high-polyphenol oils are made — early fruit, cold-pressed within hours, single-origin Tunisia, 0.3% acidity. Until then the honest phrase is high polyphenols (lab results pending).
How to keep the ones you paid for
- Buy recent harvest oil in dark glass or tin.
- Keep it away from the stove and the window.
- Use it. Phenols do not improve in a cupboard for two years.
- Cook with it. You lose some. You keep more than the smoke-point myth admits.
Longer version: What are polyphenols in olive oil?