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Production & Quality

Peroxide Value and K232/K268: The Chemistry of Olive Oil Freshness

5 min read 2025-09-15ELMAR CRETE

Is Acidity Enough on Its Own?

Acidity is an important indicator but does not alone tell how fresh the oil is. For that the laboratory makes two more measurements: peroxide value and UV absorbance (K232, K268).

What Is the Peroxide Value?

Peroxides are the first products formed when oil begins to oxidise. So the peroxide value shows the early stage of oxidation.

  • Limit for extra virgin: ≤ 20 mEq O2/kg
  • A low value = fresh, properly stored oil
  • A high value = oil worn by air, light or heat

K232 and K268 (UV Absorbance)

These tests measure how much the oil absorbs ultraviolet light at certain wavelengths:

  • K232: reflects the early stage of oxidation
  • K268: reveals advanced oxidation and the presence of refined oil

A high K268 can be a sign that refined oil has been mixed into an "extra virgin" product, making it very valuable for detecting adulteration.

Why It Matters

Together, these three parameters reveal both the freshness and the purity of the oil. Saying "extra virgin" is not enough; real quality is proven by these numbers.

ELMAR's Approach

For every production batch, acidity, peroxide and UV values are recorded in an accredited laboratory. Transparency is the foundation of trust.

Europe Olive Oil: low acidity, low peroxide, 100% natural purity — backed by EL40296.

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Cold pressed in Crete, delivered across Europe.

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