Olive oil for cooking

Olive oil is marketed as one of the healthiest cooking oils that can be used in our diet.

Extra virgin, virgin and pomace – the choice of olive oils in supermarket shelves is overwhelming but consumers are often confused with various names and grades and choose based on price and design instead of quality.

I’ll try  to demystify basic questions that come up frequently:

1. What is the difference between virgin and refined oils?
2. What are all these different categories – grades of olive oil?
3. How does olive oil affect your health?

What’s the difference between virgin and refined oils?

Refined oils like canola, vegetable or corn are traditionally used for food preparation. Price is one reason why most consumers opt for it, since it can be multiple times cheaper than virgin oils. There is nothing wrong in the fact that cooking oil is made from e.g. sunflower seeds, but if you want to maximize its’ health benefits you should make sure that it is cold pressed. Before I continue with grades, types and benefits of olive oil  I’ll try to explain what refining oil means. It seems to me that if more people knew what the process of refining oil involves, a larger number would choose a healthier cooking oil option.

Traditionally, cooking oils have been made by squeezing seeds and fruits. Extraction of oil was accomplished by simple mechanical pressure on seeds and fruit. During this process the fruit and seed cake that is left still holds a large amount of unused oil.

refined and unrefined oil

Difference between refined sunflower oil (left) and unrefined sunflower oil (right)

In industrial conditions  the process of refining oil was developed. After refining, the remains of seeds and fruits are left with only 1% of unused oil. In order to achieve this result it is necessary to add a solvent at a particular temperature to the seeds. The most commonly used solvent is hexane – a derivative of crude oil. The result of extraction of almost all oil from the seeds and fruits is a mix of hexane and edible oils. Since this mixture is not suited for human consumption, the next step in the refining process is the removal of hexane. The removal is achieved by adding a variety of different acids in a process called neutralization. The result is an edible oil without hexane. The only problem is that it isn’t visually attractive or smelling like something the average consumer would eat. This oil has to be further processed. In fact it is bleached with chemicals and deodorized to make it look and smell acceptable. A cooking oil obtained in this process is heavily chemically treated and lacks taste as well as most nutrients.

With extra virgin olive oil production chemical processes are not allowed. The only allowed processes for getting olive oil are mechanical- washing, milling, decanting, centrifuging and filtration. The highest quality oil is extra virgin olive oil.

What is olive oil?

fresh olives

Olive oil is the natural juice obtained from the fruit of the olive tree, in which the taste, aroma, vitamins and properties of olives are preserved. It is the only vegetable oil that can be consumed without further processing – freshly squeezed from olives.

There are many different types of olive oil, depending on the type of olives used for its production. Olive oil can be made ​​with only one type of olive or it can be a mixture of different types of olives. The type, age and maturity of the olives influence the taste of olive oil. That’s why the best quality olive oils have a specific taste and smell. They don’t smell or taste all the same like processed refined oils.



Guide for olive oil grades

Extra virgin olive oil – the best quality olive oil

Extra virgin olive oil is of highest quality and is obtained from the first squeezing of olives at a maximum temperature of 86 F (30 ° C). The temperature may not cause degradation or changes in the oil. You’ll recognize this kind of oil by the name “extra virgin”. Although oils extracted with the first cold pressing are much more nutritious than any refined oil, differences in quality of extra virgin olive oil do exist. Depending on the amount of free fatty acids (expressed as oleic acid) left in the oil different qualities are distinguished.

cold pressed oliveoil

First cold pressed olive oil

Check the label for free fatty acid or oleic acid content. With extra virgin olive oil, this residue should not be more than 0.8%. The smaller this percentage the better the quality of the olive oil. Extremely high quality extra virgin olive oils with less than 0.1% oleic acid content can be found, mainly made by smaller private producers.

Extra virgin olive oil must be cold pressed and have a residue of oleic acid of max. 0.8%.

The taste of extra virgin olive oil

Since extra virgin olive oil is the first squeezed natural juice from olives it is characterized by the specific taste of the olives used. It’s quality is also affected by the skills of the olive oil producer.

The taste of extra virgin olive oil can be fruity, bitter and even very tart. Because of this diversity, especially the pungent taste can be the reason olive oil is rejected by many trying it the first time. Luckily today there is a wide choice of oils you can try, from different manufacturers, and decide which you like best.

Other grades of olive oil

olive oil in shelf

Many consumers are confused by the grades of olive oil and don’t see what the difference is and why they should spend more money for extra virgin olive oil. Here’s a quick review of the remaining grades of olive oil:

Virgin olive oil

Virgin olive oil is also obtained by squeezing and without chemical processing of olives but has a higher residue of free fatty acids.

  • Virgin olive oil
    has reasonably good flavor, odor and a free fatty acid content, expressed as oleic acid, of not more than 2%
  • Lampante virgin olive oil – virgin olive oil not fitted for human consumption
    has poor flavor and odor and a free fatty acid content, expressed as oleic acid, of more than 2%

Olive oil

Consists of a blend of refined olive oil and virgin olive oils fit for consumption without further processing.
It has a free fatty acid content, expressed as oleic acid, of not more than 1%. It has acceptable odor and flavor.

Refined olive oil

Refined olive oil is obtained from virgin olive oils by refining methods that do not lead to alterations in the basic glycerin-fatty acid structure. It has a free fatty acid content, expressed as oleic acid, of not more than 0.3% and is flavorless and odorless.

Pomace olive oil

Olive pomace oil is the oil obtained by treating olive pomace (the rest of the fruits after squeezing) with solvents and has three subgroups:

  • Olive pomace
    is a blend of refined olive-pomace oil and virgin olive oils fit for consumption without further processing. It has a free fatty acid content, expressed as oleic acid, of not more than 1.0%. It’s flavor resembles the flavor of olive oil.
  • Refined olive pomace oil
    is obtained from crude olive pomace by refining methods. It has a free fatty acid content, expressed as oleic acid, of not more than 0.3% with acceptable taste and odor.
  • Crude olive pomace
    is olive-pomace oil intended for refining for use for human consumption, or it is intended for technical use.

Olive oil and your health

medical benefits olive oil

Olive oil is considered to be the main cause why people living in the Mediterranean consuming the Mediterranean diet have much less cardiovascular diseases than the rest of the world. Modern research has confirmed that olive oil has a number of benefits that positively affect our health. It is believed that olive oil helps strengthen the immune system and protects us from viruses.

Olive oil nutrition facts:
1 tablespoon olive oil (14gr) contains:
Calories – 119 kcal
Carbohydrates- 0g
Saturated fat – 1.9 g
Monounsaturated fat- 9.8g
Polyunsaturated fat- 1.4 g
Omega-3 fatty acids – 103 mg
Omega-6 fatty acids – 1318 mg
Proteins – 0 g
Vitamin E 1.9 g

In addition, there are a number of indications that olive oil also positively affects the following conditions:

Heart and cardiovascular diseases: olive oil reduces blood cholesterol (LDL) and increases levels of good cholesterol (HDL) preventing clogging of blood vessels and the occurrence of heart attacks.

Diabetes: A diet rich in olive oil with reduced saturated fats and carbohydrates has shown to be effective in the treatment of diabetes. Olive oil lowers blood sugar and increases insulin sensitivity in the body.

Stress due to oxidation and free radicals: Olive oil prevents oxidation processes in the body because it is rich in antioxidants like vitamin E, carotenoids and phenols that slow the aging process of cells.

Blood pressure: Research findings have shown that olive oil may influence the reduction of systolic and diastolic blood pressure.

Osteoporosis: High-consumption of olive oil in your diet improves the absorption of calcium and bone mineralization preventing osteoporosis.

Cancer: Researchers have noted that certain types of cancer occur less often in the Mediterranean, which is attributed to the frequent intake of olive oil. Studies show that olive oil has a protective effect against cancer especially breast, prostate and colon. It is believed that this is due oleocanthal –  a natural compound found in olive oil that has a similar effect as ibuprofen and prevents inflammation in the body.

Obesity: Although olive oil is very caloric research has shown that moderate intake of olive oil helps weight loss.

Olive oil – the use in the kitchen and frying

cooking with olive oil

Due to the high price of extra virgin olive oil the issue exists of whether to use it for cooking and frying or only for sprinkling over salads, sauces and finished meals. Also it is commonly believed that olive oil is not suitable for cooking because the healthy monounsaturated fatty acids are unstable during cooking, making olive oil even harmful for your body.

It turns out that researchers have proven that monounsaturated fats are stable at high temperatures and that there is no degradation of the healthy fatty acids while cooking with olive oil.
The smoking point, when oil breaks down and starts to smoke, of extra virgin oil is about 190-215 °C.  Most cooking takes place at lower temperatures. In other words olive oil can be used for frying and cooking, without any fear that it is harmful for you.

Olive oil is stable at high temperatures and can be used for cooking, frying and roasting without any fear of oil degradation

It is recommended to replace other unhealthier fats like refined oils, margarine or butter with olive oil whenever possible.

Storage of olive oil

Olive oil is best when consumed fresh, because it eventually oxidizes and loses its properties. Usually bottled olive oil has a shelf life of 2 years. When buying olive oil pay attention to buy the freshest bottle possible. It should be stored in dark glass bottles and kept in a dark and cold place.

It should also be kept away from heat- do not keep it near your stove as this will accelerate the process of oxidation. The cap on the bottle should be well sealed and not leaking air.

Try using extra virgin olive oil as much as possible whenever possible. If you have not used it yet or don’t like it, adjust the amount of oil that you are trying to incorporate into your diet. Initially put less until you get used to the rich taste and aroma. Over time, feel free to increase the dose. It’s worth finding regular applications of this oil in your diet because of its many health benefits.

Photo credit: Pomp-Blog by U.S. Department of Agriculture, Extra Virgin olive oil press cold. by Gabriele Cantini, Fresh Olives by Katherine Martinelli, Olive oil bottles by John Seb Barber, Adam did the cooking, in my panda pan by sharyn morrow