Polyphenols

Natural protection for olive oil and for your body

Many different components influence the taste of olive oil. Some of these components have positive health effects, others stabilize the oil or affect its flavor and aroma.

Scientific studies show that the health-promoting effects of olive oil are caused by its vitamin E content, by phytosteroles and their unique fatty acid composition and especially by phenolic compounds. These compounds are often summed up under the term "polyphenols".

The most important facts

polyphenols are secondary plant compounds
they protect the oil from rancidity
they protect the body against free radicals
olive oil polyphenols also protect blood lipids against oxidative stress
strong, green-fruity olive oils have the highest polyphenol concentrations
a bitter and pungent taste is a quality marker for polyphenol-rich olive oil

What exactly are polyphenols and how do they affect the body?

Polyphenols is the collective term for a number of different substances. These include simple phenolic compounds such as vanillic acid, gallic acid, coumaric acid, caffeic acid, tyrosol and hydroxytyrosol. Olive oil also contains secoiridoids such as oleuropein and more complex molecules like lignans and flavonoids. These are well-known phenolic compounds with strong antioxidative and anti-inflammatory properties.

Polyphenols protect cells against free radicals:
Olive oil with a high polyphenol concentration has a long self life. The polyphenols protect the oil from oxidation through oxygen and thus prevent rancidity. Polyphenols from olive oil have very similar effects for our body where they act as antioxidants and protect us from the effects of free radicals.

Free radicals specifically target lipids in the cell membrane, the DNA as well as certain proteins. Oxidative processes and the inflammatory processes in the body are closely related processes. Many degenerative diseases are related to chronic, inflammatory processes in our body.

Anti-inflammatory properties:
In addition to their antioxidative properties, olive oil polyphenols also have natural effects that ressemble the effects of Ibuprofen. Through the blockage of key enzymes that can trigger proinflammatory substances, they deactivate the inflammatory process.

Olive oil polyphenols are also able to effectively reduce important inflammatory markers in the blood.

In addition, olive oil polyphenols also have an effect on the eicosanoid metabolism, they can inhibit thrombocyte aggregation and prevent thrombosis. Especially the reduction of "bad" LDL cholesterol and the prevention of damaged, oxidized LDL cholersterol belong to the best known effects of olive oil polyphenols.

Arteriosclerosis can be reduced:
Oxidized, "bad" LDL cholesterol and consecutive reactions cause the clinical expression of arteriosclerosis. Commonly speaking, this condition that is often called "arterial calcification", may lead to thrombosis and heart attack. Free radicals are also involved in the oxidation of LDL cholesterol. These free radicals can also be intercepted very effectively by antioxidative olive oil polyphenols.

"Olive oil polyphenols contribute to the protection of blood lipids from oxidative stress"

All these positive effects caused the EFSA (European Food Safety Authority) to release the official health claim "olive oil polyphenols contribute to the protection of blood lipids from oxidative stress" in 2011. This health claim can also be found on some of our olive oil products.

At the same time, and that is a unique feature of olive oil polyphenols, olive oil also enhances the function of "good" HDL cholesterol.

Olive oil polyphenols thus have a double or even triple effect:

reduction of LDL cholesterol
protection from oxidation of LDL cholesterol
enhancement of the function of HDL cholesterol as "cholesterol transport molecule" in the blood vessels

Olive oil polyphenols therefore provide an effective protection from cardiovascular diseases.

With respect to the positive health effects of olive oil polyphenols there is a clear dose-response-relationship. This means that we can benefit from the positive health effects of olive oil only when the olive oil has a certain concentration of polyphenols. The higher the concentration of polyphenols in the olive oil the healthier the olive oil.

That is also the reason why the EFSA insists on the declaration that one should ingest at least 20 g olive oil with a content of at least 5 mg hydroxytyrosol and its derivatives in order to achieve corresponding effects.

More questions about polyphenols

Does every olive oil contain polyphenols?

No. In refined olive oils, for example, almost all olive oil polyphenols are removed through the refining process.

In "extra virgin" olive oils the polyphenol concentrations vary widely. There are olive oils with high and with low concentrations. The concentration of phenolic compounds depends both on the way how the olives are cultivated and their degree of maturity during harvest. In addition, there are also varietal differences.

The Coratina variety for example that is mainly cultivated in Apulia (Italy) is known to have the highest concentration of olive oil polyphenols. This variety is used for the production of Rapunzel olive oil extra virgin fruity. The total number of phenolic compounds and of α-tocopherol is highest in young, green olives. Oils made with these olives contribute significantly to the uptake of olive oil polyphenols.

How does one recognize olive oils with a high polyphenol content?

The polyphenol content is highest in olive oils that are characterized by a distinct "green fruitiness" and a pungent and bitter taste. The green appearance that is reminiscent of freshly cut grass, comminuted, green leaves or a freshly sliced apple is caused by flavoring substances from young, green olives. Young, green olives have the highest concentration of polyphenols that are also responsible for the oil's pungent and bitter flavor.

The polyphenolic compound "oleocanthal" for example causes the bitingly pungent taste in the back of the throat that is more pronounced the more of this compound is contained in the oil. The bitterness is due to a polyphenolic compound called oleuropein. Fresh olive oil has a higher concentration of polyphenols than olive oil that has been stored for a long time. Since polyphenolic compounds in the oil are constantly degraded and converted, an analysis of the phenolic concentration can only be a description at a specific time.

Why does olive oil taste bitter or scratchy?

Bitter substances are often considered as a quality flaw. However, as described above, a balanced bitter flavor is an official quality marker of olive oil. The bitterness of olive oil is produced by phenolic compounds such as oleuropein that are found in the olive.

Bitter-tasting foods were an essential part of the original human diet. With time, the food industry eliminated bitter substances from many foods and developed a different sense of taste - despite the important health effects of bitter substances!

Bitter substances stimulate the digestive system and influence numerous other bodily functions that are associated with the metabolic system.

What methods are used for quality assurance?

In order to guarantee extra virgin olive oil quality, all Rapunzel oils undergo thorough sensory and analytical testing. Every batch of olive oil is tested by our specifically-trained in house sensory panel and by an official olive oil panel before it is bottled by Rapunzel. Additional analytical tests are performed by renowned, external laboratories in order to secure top quality.

All olive oils bottled by Rapunzel are significantly below the legally permitted maximum values that are necessary for an "extra virgin" declaration. Because we only accept those "extra virgin" olive oils that differ significantly from the limit values of the European Olive Oil Ordinance, VO No. 2568/91. The limit values of the Ordinance specify a peroxide value of 20 or a free fatty acid concentration of 0.8. Although olive oils that comply with these values are still considered "extra virgin" one can already discern clear, sensorily detectable shortcomings. For Rapunzel olive oil, however, we accept only the best, faultless quality.