Sterols in Olive Oil | EU Limits and New Rules for Koroneiki

Sterole im Olivenöl | EU Grenzwerte und neue Regeln für Koroneiki

Can a genuine, high-quality extra virgin olive oil fall outside a standard limit for a single laboratory parameter?

When it comes to the total sterol content, this very question has become a major topic in the international olive oil industry in recent years.

Sterols are natural components of olive oil and are used in chemical analyses to assess purity and authenticity, among other things.

In principle, a minimum total sterol content applies to extra virgin olive oil. At the same time, scientific studies show that olive variety, ripeness, cultivation area, and other natural factors can significantly influence the sterol profile.

The Koroneiki olive variety is particularly interesting. It is one of Greece's most important varieties and, in single-varietal olive oils, can exhibit natural sterol profiles that have received special regulatory attention.

The International Olive Council has therefore since adjusted its marketing standard. The European Union is also working on a corresponding amendment to its regulations.

In this Green Agora guide, we explain what sterols are, why they are measured, what the limit of 1000 mg per kg means, and why the new regulation is particularly interesting for Koroneiki.

What are sterols in olive oil?

Sterols are natural components of plant-based foods and are also found in olive oil.

In olive oil, the sterol profile consists of various individual compounds.

These include, among others:

β-sitosterol
Δ5-avenasterol
Campesterol
Stigmasterol
Cholesterol
Δ7-stigmastenol
other sterol compounds in lower concentrations

β-sitosterol and related sterols, in particular, make up a large share of the natural sterol profile of olive oil.

For this reason, laboratory analysis does not only look at the total amount.

The percentage composition of individual sterols can also be important for assessing purity and authenticity.

Why are sterols in olive oil analyzed at all?

Sterol analysis is primarily part of the analytical assessment of an olive oil's purity and authenticity.

This is an important distinction.

A purity parameter does not automatically answer the same question as a quality parameter.

For example, acidity, peroxide value, and sensory analysis provide different information than the sterol profile.

Sterol profiles can help, among other things, to identify anomalies that might suggest blending with other vegetable fats.

However, sterol analysis is only one part of a much larger analytical system.

Other purity parameters include, for example:

Stigmastadienes
Fatty acid composition
Trans isomers
ΔECN42
Waxes
Erythrodiol and uvaol

A single sterol value should therefore never be viewed in isolation as complete proof of authenticity or a complete quality judgment.

How are sterols in olive oil measured?

The European Union uses a standardized method from the International Olive Council to determine total sterols and sterol composition.

The corresponding method is designated COI/T.20/Doc. No 26.

It is based on capillary gas chromatography.

The relevant components of the sample are first analytically prepared and then chromatographically separated.

In this way, both individual sterol compounds and the total sterol content can be determined.

The result for total sterols is usually expressed in milligrams per kilogram of olive oil.

A lab report might show, for example, a total sterol content of 950 mg, 1100 mg, or 1600 mg per kg.

This figure must then be viewed in the context of the olive variety, category, and the applicable limits.

The classic limit | At least 1000 mg of sterols per kg

According to the European marketing standard, a minimum value of 1000 mg of total sterols per kg generally applies to virgin olive oil and extra virgin olive oil.

The total sterol content is one of the purity criteria.

In addition, there are requirements for the composition of the individual sterols.

Parameter	Basic requirement
Total sterols	at least 1000 mg per kg
Cholesterol	at most 0.5 percent
Brassicasterol	at most 0.1 percent
Campesterol	generally at most 4.0 percent with regulated exceptions
Apparent β-sitosterol	at least 93.0 percent
Δ7-stigmastenol	generally at most 0.5 percent with regulated exceptions

This overview alone shows:

Sterol analysis is about much more than just a single number.

Why can genuine olive oils fall below 1000 mg of total sterols?

This is precisely where the scientifically and regulatorily interesting discussion begins.

Olive oil is a natural product.

Its chemical composition is not determined by a single factor.

The following influences, in particular, can play a role in sterols:

Olive variety
Degree of ripeness of the olives
Cultivation area
Climate
Water availability and irrigation
Time of harvest
Harvest year

Scientific studies of various olive varieties show a significant natural variance in total sterol content.

In a study of 43 olive varieties, for example, individual authentic extra virgin olive oils lay outside the usual regulatory ranges for total sterols or individual sterol compounds.

This does not mean that every value below 1000 mg is automatically unproblematic.

However, it does mean that a rigid limit does not always fully reflect natural, variety-related differences.

The olive variety can strongly influence the sterol profile

The genetic origin of the olive plays an important role in the chemical composition of the resulting olive oil.

This applies not only to fatty acids and aromas.

Sterols can also differ significantly between different olive varieties.

Scientific studies show that even olive varieties processed under comparable agronomic and technological conditions can develop different sterol profiles.

This is particularly important for single-varietal premium olive oils.

In a blend, the different natural compositions of several olive varieties can come together.

In a monovarietal, however, the olive oil comes entirely from a specific variety.

This makes the natural chemical character of that variety much more clearly visible.

Why Koroneiki has become particularly important

Koroneiki is one of Greece's best-known olive varieties and is used in numerous high-quality extra virgin olive oils.

Studies from Greece have shown that total sterol contents below 1000 mg per kg can occur in some authentic Koroneiki olive oils.

The problem here:

An olive oil can be authentic in terms of origin and olive variety and still fall outside a general limit for this single purity parameter.

It was precisely this observation that was one of the reasons the International Olive Council began looking more intensively at variety-related sterol values.

Koroneiki is not the only olive variety affected.

Nocellara del Belice and Coratina are now also explicitly at the center of international regulation.

What does science say about Koroneiki?

A scientific review of sterols in virgin olive oil documents several studies of Greek Koroneiki olive oils.

In individual datasets, significant proportions of the examined Koroneiki samples were below the previous limit of 1000 mg of total sterols per kg.

This is an important indication that a low total sterol content does not automatically prove that an olive oil has been adulterated.

For a reliable authenticity test, other analytical parameters must be taken into account.

This is precisely why the international olive oil industry is increasingly working with decision-making rules that combine several analytical characteristics.

Early harvest and sterols | What can really be said?

The degree of ripeness of the olives can also influence the sterol profile.

However, one should be cautious with statements here.

It is not scientifically sound to claim that every early harvest automatically causes a low sterol content.

Studies show that total sterols and individual sterol compounds can change during ripening.

However, the direction and strength of this change can depend on the olive variety and growing conditions.

In various studies, increasing total sterol values were observed with increasing maturity. Other studies show more complex or variety-dependent developments.

Early harvest is therefore a possible influencing factor, but not the sole explanation.

Learn more about the harvest time in our guide: Early Harvest Olive Oil | Understanding Early Harvest.

Climate, cultivation area, and irrigation can also play a role

In addition to olive variety and ripeness, environmental conditions can also influence the chemical composition of the olive.

These include, for example, temperature, geographical location, and water availability.

In the current discussion about single-varietal olive oils, the European Commission also mentions other influencing factors in addition to the olive variety, such as ripeness, geographical area, and irrigation.

This does not mean that a specific sterol value can be automatically predicted from a single hot season.

Rather, it shows that natural olive oils are chemically more complex than a single rigid number would suggest.

The International Olive Council reacts | New exception starting at 800 mg

International regulations have since evolved.

In its current marketing standard from June 2026, the International Olive Council continues to generally maintain a minimum total sterol content of 1000 mg per kg for virgin olive oils.

At the same time, the current standard contains an important exception.

For single-varietal extra virgin olive oil from the following olive varieties, the current IOC standard sets a minimum value of 800 mg of total sterols per kg:

Koroneiki
Nocellara del Belice
Coratina

The International Olive Council explicitly points out that further scientific studies are underway and that additional parameters for the authenticity testing of single-varietal olive oils are to be developed.

This is an important development.

It does not mean that sterols have suddenly become unimportant.

Rather, it shows that international standards can be adapted when new scientific data better explain natural, variety-related peculiarities.

New EU rule for Koroneiki and Nocellara del Belice

There is also a concrete change at the European level.

On August 21, 2026, the European Commission adopted an amending legal act to Delegated Regulation (EU) 2022/2104.

This also provides for a minimum total sterol content of 800 mg per kg for single-varietal extra virgin olive oil made from Koroneiki or Nocellara del Belice.

For these olive oils, the respective olive variety must also be stated on the label, in accompanying documents, and in further labeling.

The European Commission explicitly justifies the change by stating that authentic and high-quality single-varietal olive oils of these varieties sometimes cannot reach the general total sterol limit.

As influencing factors, the Commission mentions in particular:

Olive variety
Degree of ripeness
Geographical area
Irrigation

Important regarding the current legal status: The legal act adopted on August 21, 2026, provides for it to enter into force the day after its publication in the Official Journal of the European Union.

For a legally binding assessment, the version of the European regulation actually in force at the time is always the decisive one.

IOC and EU | Why the rules do not currently look completely identical

The current IOC standard from June 2026 mentions the exception for Koroneiki, Nocellara del Belice, and Coratina.

The amending legal act adopted by the European Commission in August 2026, however, concerns Koroneiki and Nocellara del Belice.

This shows why one must distinguish between international standards and directly applicable EU law when it comes to regulatory issues.

The International Olive Council develops international marketing standards and analytical methods.

The European Union, however, adopts changes into the European regulatory framework via its own legal acts.

There can therefore be a time and content difference between the two steps.

Is an olive oil with 850 mg of sterols therefore automatically high-quality?

No.

The new exception should not be misinterpreted either.

A total sterol content of 850 mg per kg is not automatically a quality characteristic.

Likewise, a value of 1500 mg per kg is not automatically a sign that an olive oil is sensorially better.

In this context, sterols are considered primarily as purity and authenticity parameters.

For extra virgin olive oil, numerous other criteria also play a role.

These include, among others:

Acidity
Peroxide value
K232
K270 or K268
ΔK
Fatty acid ethyl esters
Other purity parameters
Sensory analysis

A single sterol value cannot replace this overall picture.

Sterols are not a quality ranking

This exact point is particularly important for consumers.

With polyphenols, one might be tempted to compare olive oils solely based on large numbers.

For sterols, such a ranking would be even less meaningful.

An olive oil with 1700 mg of total sterols per kg is not automatically better than an authentic, single-varietal Koroneiki olive oil with, for example, 900 mg per kg.

The two values can be the result of different natural compositions.

For a professional assessment, the entire analysis must always be considered.

Sterols and polyphenols are two completely different analytical values

Sterols and polyphenols are often mentioned together in laboratory reports for high-quality olive oils.

However, they describe different substance groups and fulfill different analytical functions.

Sterols

Sterols belong to the unsaponifiable fraction of olive oil and play a role in, among other things, testing for purity and authenticity.

Polyphenols

Polyphenols are phenolic plant compounds and are examined using different analytical methods.

A high polyphenol content therefore does not automatically mean a high sterol content.

Likewise, a low total sterol content does not allow for a direct statement about the polyphenol content.

You can learn more about polyphenols under Understanding polyphenols in olive oil.

We also explain how polyphenols are analytically determined in our guide How is the polyphenol content in olive oil measured.

Koroneiki premium olive oils at Green Agora

The current discussion on sterols is particularly interesting for Green Agora because several premium olive oils in our range are based on the Greek Koroneiki olive.

We explicitly do not want to claim that these products have a problematically low total sterol content.

Without the respective complete sterol report, such a statement would not be justified.

However, the products demonstrate very well why the scientific and regulatory focus on the Koroneiki olive variety is relevant for our assortment.

Di Morea Bio | Koroneiki from the Peloponnese

Di Morea Bio is produced from Koroneiki olives and comes from Messenia in the Peloponnese.

The currently confirmed polyphenol value is 664 mg per kg.

This polyphenol value should be viewed independently of the total sterol content.

Discover Di Morea Bio

You can find out more about this premium olive oil under Di Morea Bio | Premium olive oil of excellent quality from Messenia.

Pathos Bio | Koroneiki from Crete

Pathos Bio is also made from Koroneiki olives.

The premium olive oil comes from Crete and currently shows 834 mg of polyphenols per kg.

The same applies here: the polyphenol value must not be confused with the total sterol content.

Discover Pathos Bio

You can learn more in our article Pathos Bio premium olive oil from Crete.

Kouros of Zeus Koroneiki

Kouros of Zeus also offers a premium olive oil made from Koroneiki olives from the Peloponnese.

Especially with such single-varietal products, the current development of international sterol regulation is particularly interesting.

Discover Kouros of Zeus Koroneiki

You can find out more about the producer and their analyses under Kouros of Zeus | Laboratory analyses and quality.

What does the new rule mean for consumers?

For consumers, the most important realization is not to memorize the lowest possible sterol values.

What is more important is understanding that laboratory values must be interpreted in the correct context.

If a single-varietal Koroneiki olive oil has a total sterol content below 1000 mg per kg, this does not automatically mean that it is adulterated or inferior according to today's scientific and regulatory understanding.

That is precisely why international rules have been further developed.

At the same time, the opposite should not be inferred from the new exception.

A low value does not automatically prove special quality or authenticity.

Other analytical parameters remain decisive.

What does the development mean for producers?

This development is particularly relevant for producers of single-varietal olive oils.

Monovarietals allow for a very clear representation of the olive variety, origin, and sensory character.

However, this very transparency can lead to natural variety-specific chemical properties becoming more visible than in a blend.

The new regulatory development therefore attempts to combine two goals:

effective protection against adulteration
consideration of the natural variety-related characteristics of authentic olive oils

In our view, this is the crucial balance.

Why additional authenticity parameters remain important

The adjustment of a sterol limit does not mean that controls have to become weaker.

Modern olive oil analysis works with numerous parameters simultaneously.

These include, among others, stigmastadienes, trans isomers, ΔECN42, fatty acid profiles, and other purity parameters.

The International Olive Council continuously develops its standards and decision-making rules.

The goal is to be able to better distinguish authentic natural variations from actual adulteration.

This is precisely the advantage of a multi-parameter analysis compared to an assessment based on a single limit number.

How to read a sterol report correctly

If you have a laboratory report on the sterol profile of an olive oil, you should not look solely at the "Total Sterols" line.

The following points are of particular interest:

Which olive variety was used?
Is it a single-varietal olive oil or a blend?
How high is the total sterol content?
What is the composition of the individual sterols?
How high is the apparent β-sitosterol?
How high are campesterol and Δ7-stigmastenol?
Which other purity parameters were examined?
Which batch was analyzed?
When was the analysis performed?
Which method was used?

For a regulatory assessment, the complete laboratory report and the legal situation in effect at the time of analysis or marketing should always be taken into account.

What sterols do not reveal about taste

A sterol report can provide important chemical information.

However, it cannot tell you whether you will love the taste of an olive oil.

Fruitiness, bitterness, pungency, and individual aromas are evaluated sensorially.

A premium olive oil may show notes of green herbs, artichoke, tomato leaf, almond, or other characteristic impressions.

These sensory properties cannot be derived from a total sterol content of, for example, 900 or 1400 mg per kg.

Laboratory analysis and sensory evaluation therefore complement each other, but do not replace one another.

You can learn more about holistic quality assessment under How to recognize good olive oil.

Ayhan's personal assessment of sterol limits

What I find particularly interesting about this topic is the development of the rules themselves.

A limit has an important purpose. Consumers must be protected from having an adulterated product sold as high-quality extra virgin olive oil.

At the same time, an analytical limit must reflect natural reality as accurately as possible.

If scientific data shows over years that certain authentic single-varietal olive oils have natural characteristics, I think it is right that international standards are reviewed and further developed.

The current development with Koroneiki shows exactly that.

However, for me, this does not mean that a low sterol value is suddenly a quality feature.

Just as little would I claim that a high sterol value automatically means a better olive oil.

With a premium olive oil, I want to see the whole picture: olive variety, origin, harvest, processing, laboratory analyses, and sensory evaluation.

That is exactly why I find transparent analyses so important.

Ayhan from Green Agora

You can find my personal recommendations under Ayhan's olive oil favorites.

Frequently asked questions about sterols in olive oil

What are sterols in olive oil?

Sterols are naturally occurring plant components of olive oil. Important sterol compounds include β-sitosterol, Δ5-avenasterol, campesterol, and stigmasterol.

Why are sterols measured in olive oil?

The sterol profile and total sterol content are among the analytical purity parameters and are considered, among other things, when checking for authenticity and potential adulteration.

How high must the total sterol content of extra virgin olive oil be?

In principle, a minimum value of 1000 mg of total sterols per kg applies. Special exemption rules exist or are being created for certain single-varietal olive oils.

What exception applies at the International Olive Council?

The current IOC marketing standard from June 2026 provides for a minimum value of 800 mg of total sterols per kg for single-varietal extra virgin olive oil from Koroneiki, Nocellara del Belice, and Coratina.

What is changing in the European Union?

On August 21, 2026, the European Commission adopted an amending act that provides for a minimum value of 800 mg of total sterols per kg for single-varietal extra virgin olive oil from Koroneiki and Nocellara del Belice. The published and effective version of the EU regulation is decisive for the respective binding legal status.

Why is Koroneiki affected?

Scientific studies and regulatory work show that authentic single-varietal Koroneiki olive oils can have natural total sterol contents below the general limit of 1000 mg per kg.

Does less than 1000 mg of sterols automatically mean adulteration?

No. Especially the current development with certain olive varieties shows that natural variety-related deviations are possible. An authenticity check must therefore take other analysis parameters into account.

Is a low sterol content a quality feature?

No. A low total sterol content should not be advertised as a quality feature. In this context, sterols are primarily an analytical purity and authenticity parameter.

Is a high sterol content automatically better?

No. A higher value does not form a quality ranking. Sensory evaluation, acidity, oxidation parameters, origin, olive variety, and other analytical values must also be considered.

Does the olive variety influence the sterol content?

Yes. Scientific studies show a clear genetic or variety-related influence on sterol content and sterol composition.

Does the harvest time influence the sterols?

The degree of ripeness can influence total sterols and individual sterol compounds. The effect is not identical for every olive variety, however, and should not be reduced to the simple formula that early harvest equals low sterols.

Are sterols the same as polyphenols?

No. Sterols and polyphenols are different substance groups and are considered differently analytically.

How are sterols measured?

A standardized method using capillary gas chromatography is used for the official examination. The corresponding IOC method is designated COI/T.20/Doc. No 26.

Further guides on olive oil laboratory values and quality

Official foundations of this article

For the regulatory classification of this article, the following current regulations and professional foundations were specifically taken into account:

Delegated Regulation (EU) 2022/2104 on marketing standards for olive oil
Implementing Regulation (EU) 2022/2105 on controls and analysis methods
IOC Marketing Standard COI/T.15/NC No 3 Rev. 22 of June 2026
IOC analysis method COI/T.20/Doc. No 26 for the determination of sterols
European Commission amending act C(2026)5797 of August 21, 2026
Scientific work on the influence of olive variety and ripeness on sterol profiles

Since the regulatory development for single-varietal olive oils is currently changing, the version of the European legal provisions currently in effect should always be checked for legally binding decisions.