At The Olive Orchard, we believe you should know more about your olive oil than what is printed on the front of the bottle.
True extra virgin olive oil is more than simply pressed olives. Its chemistry can tell us about the condition of the fruit when it was harvested, how quickly it was crushed, how the oil has been stored, how fresh it remains, and even some of the naturally occurring compounds that contribute to its flavor and potential health benefits. The olive tree only has one harvest per year. Northern hemisphere locations usually crush in the fall October – November and southern hemiphere locations usually crush in the spring April – May.
That is why all of our unflaovered extra virgin olive oils are accompanied by a chemical analysis taken from a sample at the time of crush Here is what those numbers mean — without the chemistry degree.
Free Fatty Acids (FFA)
A window into the quality of the olives at harvest
Lower is better.
Free Fatty Acids tell us a great deal about the condition of the olives and how they were handled before they were crushed.
Healthy, undamaged olives that are harvested and processed promptly generally produce oil with very low FFA. Bruised, overripe, damaged, or poorly stored olives tend to produce higher levels.
For an olive oil to meet the International Olive Council’s chemical standard for Extra Virgin Olive Oil, FFA must be 0.8% or lower.
What it tells you: Lower FFA is generally a sign of healthy fruit and careful handling from harvest to crush.
Peroxide Value (PV)
A measure of oxidation
Lower is better.
Once olive oil is produced, oxygen begins a slow process of oxidation. Peroxide Value measures the early products of that oxidation and therefore helps us evaluate the oil’s condition and freshness.
Heat, oxygen, improper processing, and poor storage can all accelerate oxidation.
For Extra Virgin Olive Oil, the IOC standard requires a Peroxide Value of 20 or less.
What it tells you: A low PV indicates that the oil has experienced relatively little oxidation.
Oleic Acid
The heart of olive oil
Higher is generally better.
Oleic acid is the primary monounsaturated fatty acid in olive oil and one of the reasons olive oil is so different from many other cooking fats.
It is naturally resistant to oxidation, helping the oil remain stable and fresh. Replacing saturated fats in the diet with unsaturated fats such as oleic acid can also contribute to a healthier dietary fat profile.
Extra virgin olive oils naturally rich in oleic acid tend to have excellent oxidative stability.
What it tells you: A higher oleic acid content contributes to both the nutritional character and stability of the oil.
The Biophenols
Where flavor, freshness, and fascinating chemistry meet
Biophenols — often simply called phenols or polyphenols — are naturally occurring compounds found in olives and Extra Virgin Olive Oil.
They act as antioxidants in the oil, helping protect it against oxidation. They also contribute to many of the flavors we associate with high-quality EVOO.
That pleasant bitterness on your tongue?
That peppery sensation or little cough at the back of your throat?
Those aren’t necessarily flaws. They can be signs of naturally occurring phenolic compounds.
Modern laboratory testing can use High Performance Liquid Chromatography (HPLC) to separate and measure individual phenolic compounds rather than simply estimating the total amount.
More than 20 phenolic compounds may be present in Extra Virgin Olive Oil, including hydroxytyrosol, tyrosol, oleuropein derivatives, lignans, flavonoids, and other secoiridoids.
What it tells you: Higher phenolic content generally means greater antioxidant activity, greater oxidative stability, and often a more robust, bitter, or peppery oil.
Meet Two Famous Olive Phenols
Oleocanthal
One of EVOO’s best-known phenolic compounds. Oleocanthal has been widely studied for its anti-inflammatory properties and is strongly associated with the characteristic peppery sensation felt at the back of the throat.
Hydroxytyrosol
A powerful naturally occurring antioxidant found in olives and olive oil. Hydroxytyrosol and related compounds are among the phenols studied for their ability to help protect blood lipids from oxidative damage.
DAGs — Diacylglycerols
A clue to freshness and shelf life
Higher is better.
Fresh olive oil made from healthy fruit contains a high proportion of 1,2-diacylglycerols (1,2-DAGs).
As olive oil ages, these naturally rearrange into another form called 1,3-DAGs. That makes the percentage of 1,2-DAGs useful as an indicator of an oil’s freshness and expected shelf life.
Fresh, carefully produced olive oils may begin with 1,2-DAG levels of 85% or higher. Those levels gradually decline as the oil ages, particularly when exposed to heat.
What it tells you: High DAGs are another indication of fresh oil produced from sound fruit and handled well.
PPP — Pyropheophytin A
Has the oil been exposed to too much heat or age?
Lower is better.
Olives naturally contain chlorophyll. As olive oil ages or is exposed to heat, chlorophyll pigments break down and form compounds including pyropheophytins.
Freshly produced olive oil should therefore have very little PPP — often close to zero.
PPP increases naturally with age, but unusually high levels can indicate excessive heat exposure, prolonged poor storage, advanced aging, or thermal treatment.
This makes PPP particularly useful because it can help identify oils that may have been subjected to processes designed to remove undesirable flavors from lower-quality oil.
What it tells you: Low PPP supports the story of a fresh, properly handled oil that has not been subjected to excessive heat.
Alpha-Tocopherol
Olive oil’s natural Vitamin E
Alpha-tocopherol is the most biologically active form of Vitamin E, a fat-soluble antioxidant naturally present in Extra Virgin Olive Oil.
Vitamin E helps protect cells from oxidative damage and contributes to the nutritional value and oxidative stability of olive oil.
What it tells you: Alpha-tocopherol is one of the naturally occurring antioxidants that makes high-quality Extra Virgin Olive Oil much more than simply a source of fat.
Squalene
A lesser-known natural component of olive oil
Squalene is a naturally occurring hydrocarbon found in olive oil and is also produced naturally by the human body.
It is an intermediate in the body’s production of cholesterol and other important molecules and has attracted scientific interest because of its antioxidant and other potential biological properties.
Extra Virgin Olive Oil is one of the richer dietary sources of squalene.
What it tells you: Squalene is another example of the many naturally occurring minor compounds found in EVOO that are being studied for their potential contribution to health.
So, What Should I Look For?
You don’t have to memorize the chemistry.
Think of it this way:
| Measure | Generally Look For | What It Helps Tell Us |
|---|---|---|
| FFA | ↓ Lower | Quality of the fruit and handling before crushing |
| Peroxide Value | ↓ Lower | Oxidation and condition of the oil |
| Oleic Acid | ↑ Higher | Fatty-acid quality and oxidative stability |
| Biophenols | ↑ Higher* | Antioxidants, stability, bitterness and pungency |
| DAGs | ↑ Higher | Freshness and expected shelf life |
| PPP | ↓ Lower | Aging, heat exposure and possible thermal treatment |
| Alpha-Tocopherol | Naturally present | Vitamin E and antioxidant activity |
| Squalene | Naturally present | A bioactive minor component of olive oil |