What is vegetable oil?
A few weeks ago, Science Avenue published an article on palm oil. The article was intended to shed light on environmental destruction, as well as human rights violations, that result from the consumption and production of the cooking ingredient. In contrast, this week’s column will look at vegetable oil from a purely pharmacological and chemical perspective.
Vegetable oil is a rather simple compound to consider. Under most definitions of the term, vegetable oil is nothing more than a triglyceride extracted from a plant. Most people consider vegetable oils as liquids at room temperature – olive oil and grapeseed oil, for example. This definition eliminates solids at room temperatures – vegetable fats, for instance – but it is true that other broad definitions treat plant extracts in various states of matter as “vegetable oils” as well.
Regardless of the technical definition, one thing remains unchanged: vegetable oils have been a part of human civilization since the dawn of time. Our ancestors used a variety of vegetable oils for cooking, illumination, as well as for cleaning products like soaps.
How does vegetable oil work?
The modern method for vegetable oil extraction remains similar to the methods of our ancestors. While we’ve begun to use complex chemistry to produce higher yields of certain oils, the traditional method of crushing and pressing olives, grapeseeds, and avocado seeds remain in use. Granted, modern factories allow for a greater number of processes at any given moment, but, outside the realm of chemical extraction, most producers use mechanical presses to draw vegetable oil from its sources.
Why is vegetable oil important?
In recent years, a widespread cultural shift has led to the examination of the health benefits of various vegetable oils. Since the consumption of any fat has become highly scrutinized, it should come as no surprise that vegetable oils have been studied for their health benefits and potential detriments.
Should, for instance, olive oil be used to grill or fry foods? Is virgin oil healthier than regular oil? What’s the best – and safest – oil to use when using heat to prepare food? These are the kinds of questions that modern food scientists have asked in order to learn more about the oils humanity has used since antiquity.
Smoke point is the temperature at which visible gases begin to form when heating cooking oils. The smoke is a result of the release of potentially toxic compounds trapped within the oil. The temperature at which smoke is released differs between various oils. When individuals claim that it is unsafe to consume certain oils at higher temperatures, they are referring to the fact that harmful compounds are only released when specific oils are heated to specific temperatures.
Virgin olive oil, for instance, has a smoke point of 199 degrees Celsius. This means that it is safe to consume virgin olive oil at temperatures below 199 degrees, but, any higher and there is a chance that any toxins embedded within the oil will slowly be released. In comparison, avocado oil has a smoke point of 271 degrees Celsius, which means that avocado oil can safely be used in extreme temperature situations – like deep-frying – without potentially harming hungry individuals.
What, then, of the distinction between virgin, extra-virgin, and regular oils? In terms of oil, virginity refers to the acidity and purity of oil. For olive oil to be classified as “virgin,” for instance, it must have a maximum acid value of 6.6. Extra virgin olive oil can have a maximum acid value of 0.6.
At low temperatures, normally reserved for salads and dips, most vegetable oils are judged based on taste. However, in the preparation of hot foods, the type of oil used can contribute to a variety of health effects, based solely on the temperature used to prepare the food.
What is the future of vegetable oil?
As food science advances, our decisions to use certain oils will be informed by our understanding of factors like smoke point and acid value. However, the issue of misattribution continues to plague the vegetable oil industry, regardless of scientific advancement. The issue of misattribution has to do with manufacturers claiming that their oils are “Virgin” or “Extra virgin,” when their products are otherwise normal variations of vegetable oils. Due to the lack of regulation over the vegetable oil industry, manufacturers are able to mislabel their products and reap the profits of their exploits.
As vegetable oil use continues, and consumers grow savvier, I believe that manufacturers will no longer be able to mislabel their products and exploit their customers.