There are various grades and types of olive oil; how can we tell the difference?
Olive oil is simply the oil extracted from the olive fruit. Yet there are several grades and qualities of olive oil. What are the differences?
Extra virgin olive oil is the juice of the olive fruit, with no additives, chemical or thermal processing, and is therefore a natural product. To qualify as “extra virgin” it must have no defects, which means it must not taste or smell muddy, musty or rancid; it must reach certain standards regarding aroma and taste with respect to its fruitiness, bitterness and pungency; and it must have particular chemical properties such as acidity levels less than 0.8%. This type of oil has high antioxidant levels offering the most nutritional benefits and is also the most flavorful.
Virgin olive oil has a higher level of acidity (up to 2%), lower levels of nutrients, and some defects affecting its aroma and flavor, which may have emerged due to use of overripe olives or delays in milling. It is therefore less expensive than extra virgin olive oil. It also has a lighter taste and flavor compared with most extra virgin oils, on account of its lower antioxidants.
Refined olive oil is made of virgin olive oil that due to many defects is unfit for human consumption, and is subjected to physical or more often chemical processing to remove the defects and make it edible. Chemical processing includes treating it with solvents like sodium hydroxide and subjecting it to high temperatures and other processing methods, in order to produce oil that is colorless, tasteless and odorless. The result is to remove not only the defects of the virgin olive oil but also its important nutrients and antioxidants.
Olive oil consists of a blend of refined olive oil (explained above) and virgin olive oil. Usually it is about 90% refined oil to 10% virgin oil. In fact the virgin oil is added to the refined oil in order to provide some taste and color. The result is often labeled Light Olive Oil or Extra Light Olive Oil or Pure Olive Oil. As it is composed mainly of refined oil, this type of oil is also for the most part bland and tasteless, and is very low in nutrients and antioxidants. In some cases it is blended with vegetable oils, such as canola oil.
If you buy Light, Extra Light, or Pure Olive Oil, you are buying an inferior, highly processed product, with few if any of the nutrients, antioxidants and anti- inflammatory properties, as well as taste and aroma properties, that olive oil is so famous for.Olive pomace oil is made of the olive pomace (the residue after crushing, consisting of pits and flesh of the olives) that is highly processed by use of chemical solvents and heating to be made fit for human consumption. The processes used to make olive pomace oil may result in the formation of harmful substances that may be carcinogenic. In fact olive pomace oil is not considered to be olive oil at all.