Cold-Pressed Avocado Oil: The Mother of All Oils
AVOCADO TOAST…has absolutely nothing to do with this article. However, this is the number one food trend which is derived from the avocado fruit. Yes, that’s right, I said fruit. Believe it or not, it’s not a vegetable. Although prices have skyrocketed for this green gem, there is another way to reap its health benefits without running your pockets dry.
No, I won’t tell you to gulp down a whole bag full of avocados or to eat the skin and seed of the fruit. What I’m talking about is consuming the nutrient-dense oil extracted straight from the avocado flesh, known as cold-pressed avocado oil (CPAO).
Background on Cold-Pressed Avocado Oil
Historically, the majority of avocado oil was retrieved using harsh methods (high temperature coupled with solvent extraction). The oil followed typical refining steps (refining, bleaching and deodorising), resulting in a pale yellow oil. Rather than consumption, the oil was primarily used in the cosmetic industry for its ability to:
- Absorb rapidly into the skin
- Retain a high vitamin E content ( good for dry skin)
- Create lather effects for soaps and
- Create smooth creams
Now, you may have heard of cold-pressed or extra virgin olive oil, but what about its avocado counterpart?
Cold-pressed avocado oil or CPAO is somewhat new to the organic oil scene. Blueprints of CPAO extraction were already devised in the late 1980s. Interestingly, during this time period, the general population was more accepting of refined oils. As the consumer trend towards more “natural” foods grew, unrefined cold-pressed avocado oil became more marketable. Soon after 2000, the first commercial extraction of CPAO was successfully established in New Zealand.
What does Cold-Pressed Mean
You may have heard the term cold-pressed or extra-virgin and wondered what the heck does that even mean!? Both these terms refer to a similar extraction process, where the oil is removed from the fruit flesh at temperatures below 30–50˚C (86–122 ˚F).
Cold-pressed extraction exists to retain the natural flavours and properties already present in the fruit itself. The most eye-catching aspect of CPAO is its brilliant emerald green shine when extracted. We can thank the high concentration of natural chlorophyll for this. However, chlorophyll is very sensitive. Hence, under storage or exposure to heat, light and oxygen, the avocado oil turns yellow/gold with the loss of chlorophyll pigments.
How is it made?
Avocado selection
Even though we refer to this nutritious fruit solely as “avocado” there are many different varieties. Hass avocado, originally bred in California, is the avocado of choice for oil extraction. Generally, Hass has superior yields and fruiting characteristics such as tough skin (useful for transportation) and high oil content (16–17% in September to 25–30% in April).
The avocado oil industry in most countries relies on using the “reject grade” fruit from commercial pack-houses. Reject grade fruits are those, that have not met export or local-market quality standards. Generally, growers do not receive an economic benefit from “bottom class” fruit sales. Therefore, rather than being discarded, they are sold to CPAO producers in bulk.
Extraction of CPAO
Processing cold-pressed avocado oil, requires 6 simple steps, as outlined below:
1. Washing
2. De-Stoner
3. Grinder
4. Malaxer
5. Decanter
6. Centrifuge
Firstly, the avocados are washed and sent up through a conveyer belt into the de-stoner. Here, the seed and around 90% of the skin is separated from the avocado flesh. A small percentage of skin is retained to intensify the oils green colour and stability. Next, the avocado pulp is sent into a grinder rotating at 1400 RPM. At this stage, the cell walls of the avocado flesh and skin are ruptured, releasing trapped fats and green chlorophyll pigments. After crushing, the avocado mash is pumped into the most crucial step of the extraction, the malaxer (kneading machines).
The malaxer is a stainless steel tank, equipped with a central screw that continuously stirs the avocado paste at a controlled temperature (lower than 50˚C and malaxing time below 90 minutes). Small oil droplets separate from the pulp and merge together into larger droplets, this is known as “coalescence”. Separation of oil from solid and liquid phases is done using a centrifuge decanter. This device uses high acceleration speeds to separate solids and liquids based on weight. The oil phase is then pumped out into a centrifuge. Any residual water is removed before creating the final product. Usually, the oils are sent into large tanks, sparged with nitrogen (increases the shelf life of oil) and are packaged when required.
Health Benefits of CPAO
Now that we’ve shifted through the technicalities of cold-pressed avocado oil. Why exactly should you be consuming it?
Get Your Fats Straight! A Quick Lesson on Fats.
CPAO is rich in fats, more specifically it is made up of saturated, monounsaturated and polyunsaturated fats.
Saturated fats (SFA) are solid at room temperature and primarily sourced from animals, yet large amounts are also found in coconut, peanut and palm oil. For the purposes of this article, it is important to know that not all saturated fats are the same when digested. Furthermore, different foods contain various types of saturated fats. Many of us grew up thinking that saturated fats are in fact detrimental to our health. However, there is simply not enough scientific evidence to back this claim — do not fear the saturation, my friends.
Monounsaturated fats (MUFA) are usually found in nuts, olive oil and avocado oil. The molecular structure of unsaturated fats makes them liquid at room temperature as they are unable to stack together as easily as saturated fats.
Polyunsaturated fats (PUFA) are made of two main groups, including omega-3 and omega-6. The ratio between these two types of PUFAs can be used to determine how healthy the oil is.
Follow the link here for more information on fat types
Avocado oil contains around 65–70 % MUFAs, 12–19% SFA and 12–16% PUFA. Generally, saturated and monounsaturated fats are considered good for your health. However, some studies have shown that a diet high in both omega-3 and omega-6 could lead to inflammation and other health problems.
CPAO, on the other hand, scores well in this area as it is comprised of more than 85% of beneficial fats. Research has also found that 60–80% of monounsaturated fats are composed of Oleic acids, which has shown to reduce the risk of coronary heart disease (CHD).
It's All About Vitamin E Baby!
Avocados are rich in vitamins (vitamin A, C, E, K and B), minerals, carotenoids (lutein) and phytosterols (beta-sitosterol).
As we all know by now CPAO is a very gentle extraction of oil. Therefore, a large amount of vitamin E is retained after removal of oil from the fruit. The most biologically active form of vitamin E is α-tocopherol, which can act as an antioxidant agent to reduce oxidative stress generated in the body. What that basically means is that it can reduce the presence of inflammation and ballooning in the liver caused by fatty liver disease.
Microbe Killing Oil!
Food poisoning is caused by the intake of food or beverages that have been contaminated with viruses, bacteria, parasites or chemicals. Interestingly, a recently published study found CPAO to inhibit the growth of certain contaminant bacteria. The researchers suggested this was possible due to the lipophilic (fat-loving) properties of CPAO, which allows it to penetrate through lipopolysaccharide (fat and sugar) layer of the bacteria, inhibiting its activity.
Oil for thought
With consumers moving towards consumption of “natural foods”, there has been a steady increase in demand for cold-pressed avocado oil. Currently, research is being conducted on optimising extraction conditions, as well as how CPAO interacts with our bodily functions. Hopefully, this article has provided you with a better understanding of cold-pressed avocado oil. More importantly, my hope is it will aid your battle between picking avocado oil or avocado toast! Remember, at the end of the day, you’re a bad hass.
