Course 1: Olive Oil Basics

Lesson 1: What is Extra Virgin Olive Oil?

We’ve all heard and know that Extra Virgin Olive Oil (EVOO) is good for your health. But what it practically means for olive oil to be Extra Virgin, how is this validated and what it takes for that to be achieved?

Learn About High Phenolic EVOO

by Jan 17, 2018

Extra Virgin Olive Oil

Extra Virgin Olive Oil is practically olive oil in its purest possible form. Simply put, healthy olives need to be crushed soon after they’re harvested and the oil should be extracted only through physical means instead of chemical ones. Of course, storage is of big importance.So, the main factors for the quality of olive oil are:
  • Condition of olives
  • Time and type of storage of the olive fruit between harvesting and pressing.
  • Method of extraction (Temperature, solvents, etc)
  • Storage of the olive oil

How do we know the necessary practices have been followed? All oils classified as EV have to be tested for their chemical and sensory features. A chemical analysis validates that specific unwanted features are below a certain value as shown below:

Type Limit for EVOO
Acidity % (w/w) 0.8
Peroxides (mEq O2/kg ) 20
K232 2.5
K270 0.22
ΔΚ 0.01
Are you curious about Myrolion’s chemical analysis for 2020? Click here! Let’s see what those are.
Olive oil consists mainly of fats. When too much time goes by or the factors described above are treated poorly, those fat molecules break down, forming free fatty acids. The free fatty acidity is thus a direct measure of the quality of the oil, and reflects the care taken right from blossoming to the eventual sale and consumption of the oil. When olive oil is exposed to the atmosphere, oxygen molecules dissolve into the oil in a process called oxidation. That’s bad news for olive oil. Peroxides are the main products of oxidation and severely degrade the flavor and nutritional value of the oil. Oxidation can also occur in the absence of exposure to air as well, in a process called auto-oxidation, because of free radicals that are present in the oil. Another way peroxides can increase is by exposure to light and the respective process is photo-oxidation. So, just like it says in the label, make sure to store it in a cool and dry place! Another way to see how respectfully  the product was created is through Spectroscopy. Specifically we test the absorbance of ultraviolet (UV) light by the olive oil in the wavelengths of 232 nm (K232) and 270 nm (K270). Those values are then mathematically processed and ΔΚ is calculated. Those three values provide us with very useful information regarding possible rancidity, oxidation and even more serious flaws such as refinement and adulteration.
A sensory analysis is performed by a group of highly trained connoisseurs who are able to study the quality of the oil through its flavor. There are specific features that can classify olive oil as Extra Virgin:

Value for EVOO classification

Fruity (Mf)>0 Greater than 0
Bitter (Mb)>0 Greater than 0
Pungent (Mp)>0 Greater than 0
Defects (Md) Exactly 0
The fruity characteristic reminds of a fresh sligthly unripe fruit. It will give you a pleasant experience and it can even make you drool, so watch out. The bitter characteristic will generate an acrid sensation at the back of your tongue. The pungent characteristic will make you experience a peppery sensation on your mouth, and even more likely in your throat. The intensity of those flavors are also largely related to the variety of the olive fruit. Some varieties generate intense features while others make it easier to combine with other ingredients by being mild. A big list of defects can be identified during a sensory analysis. Each defective flavor can be directly related to wrongdoings during the production and storage.
There are many more positive characteristics that can be identified during a sensory analysis and they mostly depend  on the variety as well as harvest timing. For instance, a trained connoisseur can identify the features “almond” , “green apple” and “artichoke” in Myrolion. You can find a list here. Although you might not be an olive oil expert, the good news is that you can still identify the basic features that will help you realize If the oil you’re tasting is actually EV or not.

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Acidity has to be greater than 0.8 % (w/w) for olive oil to be classified as Extra Virgin.