Vegetable Oils- How do we get Oil from Vegetables?
Let’s talk Nutrition, this post is all about “Vegetable Oil”. Plant based oils are sometimes considered to be nutritious and healthy. Our post today is going to explore how these oils are processed and made, and help you make your own decision on what is healthy.
A lot of recipes, or food prep methods call for use of Vegetable Oil. Cooking, baking, marinades, dressings, the applications and uses of plant based oils in food these days really are limitless. Did you ever wonder how we get oil from Vegetables? Yeah me too, and the answer may surprise you.
We do not get oil from vegetables; most plant based oil comes from seeds or pits. The most common sources of plant based oils are Olive, Canola, Cottonseed, Sunflower, Safflower, and Soybean. There are many other sources if you would like to take a look. There is some degree of processing involved to extract oil from seeds, let’s take a look at common oil production methods and how oil is made from seeds:
Plant Based Oil Processing Methods, Defined
Here is a breakdown of how plant based oils are produced:
- Solvent Extracted
- Expeller Pressed
- Cold Pressed
Solvent Extracted oils are produced by grinding seeds down to a paste, and introducing a chemical solvent to help extract the oil (the most common chemical used for this method is Hexane). The solvent chemicals are removed after the process, giving us Vegetable Oil.
Commercial companies claim that all of the solvent chemicals are removed at the end of the process, however they are not able to guarantee there are not trace amounts left in the finished product. The end result is a highly efficient oil production process, which can extract 98-99% of oil from the seed. Due to the high efficiency of this process, solvent extracted oils are often the cheapest (and most widely available).
Expeller Pressed Oils are produced by a mechanical process, which does not involve chemical solvents. The expeller presses the oil from the seeds, and this process also produces some heat (140-210 degrees F).
The heat produced in the process actually helps press more oil from the seed, however it is not as efficient as solvent extracting, typically pulling 60-70% of oil from the seeds. If you note on the product label that the oil you are using is expeller pressed, you may be assured that solvent extraction was not used in production.
Cold Pressing is also done via mechanical means, similar to expeller pressing, however the temperature may not exceed 110 degrees F to be labeled Cold Pressed.
Cold Pressed is the least processed plant based oil, and is popular among consumers because the flavor of Olive, Avocado, etc. is not fundamentally altered by heat or a chemical extraction process. As you may imagine, cold pressing is less efficient than expeller pressing due to lower temperature, and typically cold pressed/cold processed oils will cost more to buy.
Cracking the Code
If you want to be sure of the processing method of oils you buy, you must read the label and research the company. Unfortunately, companies are not required to list on their label if they use solvent extraction as their processing method.
To crack this code, follow these guidelines:
- Is the oil you are buying is very low in price?
- Is the processing method listed on the ingredients label?
- If yes to question 1 and/or no to question 2, you can make a reasonable assumption that it is solvent extracted.
For a quick and easy guide to reading and understanding nutrition labels, take a look at my blog post on this topic. What you’d want to see to make sure you are avoiding solvent extracted Oil are key words like “First, Cold Pressed Extra Virgin Olive Oil”, or “Expelled Pressed Canola Oil”. If the label simply reads “Canola Oil”, that is an indicator it may be solvent extracted.
We will explore potential health implications of these different processing methods of plant based oils on a later post, but for right now the general theme follows the same guideline as my previous posts:
If food you are choosing highly processed, and fundamentally altered from its original state, this food is probably not the healthiest choice available.
Vegetable Oils in Summary
- The Cheapest Oil is likely solvent extracted
- Companies are not required to label solvent extracted oils as such
- Cold Pressed Oil is the least processed of all plant based Oils
Food for thought, next time you restock your Vegetable Oil!