Frying olive oil too long breaks down its natural compounds and creates new ones—but adding olive extract slows this breakdown and even boosts total antioxidants for the first few hours.

Scientific Claim

Prolonged deep frying of extra virgin olive oil at 210°C for more than 18 hours causes significant degradation of secoiridoid derivatives (e.g., oleuropein, ligstroside) and increases oxidized isomers, but supplementation with olive fruit extract delays this degradation and increases total phenolic content up to 6 hours of frying.

Original Statement

“Oxidized secoiridoid derivatives increased significantly as DF progressed... TPC increased in these experiments with the onset of the deep frying process... E.1 and E.3 exhibited a significantly greater amount of TPC (p < 0.05)... with values of 879.93 and 920.68 mg/kg, respectively.”

From study:Improving the Biostability of Extra Virgin Olive Oil with Olive Fruit Extract During Prolonged Deep Frying

Evidence Quality Assessment

Claim Status

appropriately stated

Study Design Support

Design supports claim

Appropriate Language Strength

definitive

Can make definitive causal claims

Assessment Explanation

The study directly measured secoiridoid and TPC levels over time using validated HPLC methods. The observed increases and decreases are empirical, statistically significant, and reproducible across replicates.

Evidence from Studies

Supporting (1)

Improving the Biostability of Extra Virgin Olive Oil with Olive Fruit Extract During Prolonged Deep Frying

Cross-Sectional Study

In Vitro

2025 Jan 15

Adding a special extract from olives to frying oil helps it stay healthy and tasty longer, even when heated for a long time—especially up to 6 hours.

Contradicting (0)

No contradicting evidence found

Source Study

Improving the Biostability of Extra Virgin Olive Oil with Olive Fruit Extract During Prolonged Deep Frying

Score: 5

DOI: 10.3390/foods14020260

Similar Assertions

When you add olive extract to frying oil, it helps keep more of the natural plant compounds that give olive oil its health benefits—even after long frying.

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Adding a natural olive extract to olive oil helps it resist going rancid when used for deep frying at high heat for a long time—much longer than plain olive oil.

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When you add a special olive extract to olive oil, the healthy antioxidants in it don’t break down as fast—even when you fry it for hours at high heat.

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After frying for 12 hours, regular olive oil loses almost all its healthy compounds, but extra virgin olive oil still keeps about a third of them — adding sesame oil doesn’t help preserve them.

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