What are polyphenols?
Polyphenols are a group of natural compounds produced in the olive tree. They act as the plant's own defence against sun, pests and oxidation. When olives are pressed into oil, the polyphenols carry through into the final product.
In olive oil, hydroxytyrosol and oleocanthal in particular receive attention. They influence both the oil's flavour profile and its stability over time.
Why does polyphenol content matter?
Polyphenol content is one of the most important quality markers for olive oil. An oil with high polyphenol content has typically been pressed quickly after harvest, from olives picked early in the season.
The polyphenols contribute to the oil's taste. A high level produces a more pronounced pepperiness and some bitterness, often described as signs of a fresh, well-preserved oil.
They also serve a practical function: polyphenols act as natural antioxidants and help the oil stay fresh longer without turning rancid.
What affects polyphenol content?
Several factors determine how many polyphenols an olive oil contains.
Olive variety. Some varieties have naturally higher levels. Lastovka, grown on Korčula in Croatia, is an example of a variety that consistently delivers high polyphenol values.
Harvest timing. Olives picked early in the season contain more polyphenols. Content drops as the fruit ripens, which means producers who harvest early often get a lower yield but higher quality.
Pressing. Rapid pressing at low temperature preserves polyphenols better. The longer the time between harvest and pressing, the more the oil loses in content.
Storage. Even after pressing, polyphenols continue to decrease. Light, heat and contact with air accelerate breakdown.
How many polyphenols does a typical olive oil contain?
Most olive oils sold in grocery stores sit around 100–250 mg/kg. Many are considerably lower.
Premium olive oil often sits around 250–350 mg/kg. Vala Selection Core is 700+ mg/kg and Vala Selection Pre-harvest is 1000+ mg/kg.
Our values are HPLC verified at batch level.