When extra virgin olive oil (EVOO) is exposed to heat, its chemical composition undergoes changes, influenced by factors such as temperature and duration of exposure. Olive Oil's smoke point comes higher than you would think - around 395 degrees (200 C), and that's when you start to see the real changes in the health benefits.
1. **Low Heat:**
- At low temperatures, EVOO is relatively stable. Fatty acids, such as oleic acid, are less prone to oxidation.
- Polyphenols, which contribute to EVOO's antioxidant properties, may start to degrade slightly, but the impact is minimal.
2. **Moderate but Consistent Heat:**
- Prolonged exposure to moderate heat can lead to the breakdown of triglycerides in EVOO, resulting in the release of free fatty acids.
- Oxidation of unsaturated fatty acids may occur, producing peroxides and aldehydes, which can affect the oil's flavor and aroma.
- Polyphenols continue to degrade, diminishing the oil's antioxidant capacity.
3. **High Heat:**
- High heat accelerates the oxidation of fatty acids, causing the formation of more harmful compounds, such as trans-fatty acids and lipid peroxides.
- Polyphenols experience significant degradation, leading to a loss of the oil's health-promoting properties.
- The breakdown products of polyphenols and fatty acids contribute to changes in the sensory characteristics of the oil, including flavor and aroma.
High heat for extra virgin olive oil is generally considered to be above its smoke point, which is around 395°F (200°C). At temperatures beyond the smoke point, the oil undergoes significant chemical changes, including the breakdown of fatty acids. To maintain the nutritional and sensory qualities of extra virgin olive oil, avoid subjecting it to temperatures exceeding its smoke point. However, even Julia Child recommends deep frying at 375 degrees - so any kind of cooking with olive oil is fine. It's just healthier to keep it below it's smoke point (see video).
During the malaxation process in olive oil production:
- Malaxation involves the mechanical stirring or kneading of the olive paste to facilitate the coalescence of oil droplets.
- The temperature during malaxation is carefully controlled to optimize oil extraction without compromising quality.
- Excessive heat during malaxation can accelerate the degradation of polyphenols and lead to undesirable changes in the oil's taste and aroma.
In summary, while moderate heat is generally tolerated by EVOO, both low and high temperatures can impact its chemical composition. It is crucial to handle EVOO with care, especially during processes like malaxation, to preserve its quality and health benefits.