What is a botanical oil and how do you pick the right one for your skin?
One of the questions I'm asked most is what is a botanical oil?
Botanical oil is just a fancy name for plant oil.
Depending on the type of oil, one of three parts of the plant is used for extracting the botanical oil:
- Seed: sunflower, apricot, meadowfoam seed, apricot
- Fruit: olive, rosehip, avocado
- Nut: shea, argan, jojoba, almond
There are two ways botanical oils are extracted from the seeds, fruit, and nuts.
- Expeller pressed
- Solvent extracted
Expeller Pressed Botanical Oils
Here at Rain Organica, only expeller pressed oils are used. In ancient days, expeller pressing looked like two huge concrete wheels with a trough around the edge of it to collect the oil. There's a picture of one of these ancient presses below to give you an idea of what these look like.
A millstone for pressing olive oil.
The TLDR on expeller pressing and cold pressing
Nowadays, screw type expellers like this one below are more common.
A screw-type oil press.
Regardless, the expeller presses the oil from the seed, nut, or fruit and the oil collects in a trough or collection vessel underneath the expeller.
Expeller presses generate a lot of heat because there's a lot of friction created as the oil is pressed from the plant matter, so it's very common to control the temperature of the expeller pressing process using coolers to dissipate the heat maintaining a low temperature that doesn't cause the oil to start breaking down.
The more fragile the oil, the more necessary it is to use a cold press expeller.
How do you know how fragile a botanical oil is?
The fatty acid profile of an oil is one of two key things that determines how fragile it is. There are three types of fatty acids:
- Saturated fats
- Monounsaturated fats
- Polyunsaturated fats (this category includes all omega-3 and omega-6 fatty acids)
Here's what you need to know about a fatty acid.
- Fatty acids are always bound to a triglyceride backbone. Think of the triglyceride as a wall with three steel beams sticking out from it all pointed in the same direction (so, you're looking at one side of the wall and sticking straight out from it is three steel beams).
The wall is the triglyceride backbone and the three steel beams are three fatty acid chains (tri = 3). When you eat fats (triglycerides), the fatty acids get cleaved off in the digestive tract, distributed through the body, and then rebound to a triglyceride backbone for storage in fat cells.
Fatty acids get used directly to build and repair cellular membranes. The cell membrane of every cell in your body contains fatty acids. This includes skin cells.
- Fatty acids are different lengths. All fatty acids are made up of repeating units of carbon known as carbon chains.
The length of the carbon chain (steel beam) determines how the fatty acid is named, here's a quick example of what I mean by that: A saturated fatty acid with 10 carbons long is capric acid. A saturated fatty acid with 18 carbons is stearic acid.
The length of the fatty acid contributes to the melting point of the oil (the shorter the length, the lower the melting point) and also determines the skin feel and skin benefits of the fatty acid.
Any triglyceride can have 3 different fatty acids (steel beams) attached to it all of different lengths.
- Fatty acids have different abilities to conform/react. Hang with me for a sec here because we've just circled back to the key difference between saturated, monounsaturated, and polyunsaturated fatty acids.
Imagine that the steel beam has a joint in it. That joint is super bendy, kind of like your hip joint, it's able to bend front, back, side to side, and make a full circle.
A monounsaturated fatty acid has one joint in the steel beam (one degree of unsaturation). This is an area of the carbon chain where because of how the carbons are bound to each other, there's a weak spot, a spot where the chain can be reformed.
Polyunsaturated fatty acids have multiple joints in the steel beam (two or more degrees of unsaturation). Each of these area is a weak spot, a spot where the chain can bend and be modified, reshaped and reformed.
Generally speaking, the more degrees of unsaturation, the shorter the shelf-life of the oil. Because monounsaturated and polyunsaturated fatty acids are more flexible (bend-y), the more degrees of unsaturation, the lower the melting point of the oil too.
Let's look at this one more time in a different way along with some examples of botanical oils commonly used in skincare that are rich in saturated, monounsaturated, and polyunsaturated fatty acids.
Saturated Fatty Acids
Structure: Saturated fatty acids have no double bonds (no degrees of unsaturation) between the carbon atoms in their chains. The lack of double bonds makes them more rigid and less reactive, so ... saturated fatty acids are usually solid at room temperature with a long shelf-life.
Examples in Skincare: Coconut oil and shea butter are rich in saturated fatty acids.
Monounsaturated Fatty Acids
Structure: Monounsaturated fatty acids have one double bond in their carbon chain. They're liquid at room temperature and generally less stable than saturated fatty acids.
Examples in Skincare: Olive oil and avocado oil are high in monounsaturated fatty acids.
Polyunsaturated Fatty Acids
Structure: Polyunsaturated fatty acids have two or more double bonds in their carbon chains.
Polyunsaturated fatty acids include all omega-3 and omega-6 fatty acids, several of these fatty acids are absolutely essential for life (your body needs them to function properly and since your body doesn't make these on its own, you must get them from your diet... since skincare is an extension of your diet, adding these into your skincare routine is one way to feed your body these essential fatty acids).
Examples in Skincare: Flaxseed oil, hemp seed oil, and evening primrose oil are a few oils that are rich in polyunsaturated fatty acids.
Over the next few weeks, we'll be looking more closely at the botanical oils used here at Rain Organica.
In the meantime, in case you're curious about how these oils feel individually on your skin, check out this upcoming body oil workshop "Your ticket to flake-free legs".
About the Author
Brandy's a formulation scientist and self-proclaimed health geek who loves hiking, gardening, bird-watching, and body boarding.
Her struggle with acne during her teens and 20s led to a holistic and healthy approach to skincare, embracing skin as an organ to be loved and cared for rather than a canvas to wage war on.
Since 2008, she's been developing all-in-one products for a simple routine at home, & Rain Organica started when her backpacking friends asked for a portable skincare routine to keep their skin healthy & happy on and off the trails.
You can try Rain Organica for yourself with The Essentials Kit, a complete skincare routine in just 3 steps.
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