catsittingstill (![[personal profile]](https://www.dreamwidth.org/img/silk/identity/user.png)
catsittingstill) wrote2020-04-21 04:59 pm
catsittingstill) wrote2020-04-21 04:59 pm
On the source and safety of Canola oil.
Just got a comment on a Facebook post saying I shouldn’t use canola oil because it is “very unhealthy and ‘created’ with all kinds of non-food chemicals.”
*rolls up sleeves*. Okay folks, let’s do this thing.
What is canola oil? I’ve never seen a canola, do you have to round them up like cattle, or pick them off trees like apples or dig them up like potatoes, or what? Are they really not food?
It all goes back to a plant with the inauspicious moniker of “rape,” from “rapum” the Latin name for, of all things, turnips. This is less weird than it sounds, because the plant belongs to the Brassicaceae family which includes cabbage, mustard and turnips, (honestly the family lineage reads like a particularly well-stocked grocery: cabbage, mustard, kale, broccoli, cauliflower, collards, Chinese cabbage, horseradish, radish and thale cress.)
The main point of this particular species is its pods and specifically the seeds inside, which are rich in oil. The seeds, and the meal produced by processing them for the oil, can be used for animal feed and the oil can be used for biodiesel production as well as cooking, and sometimes as a replacement for petroleum in non-food products like newspaper ink. Despite the modern uses, this plant has been cultivated for thousands of years, starting in India in 4000 BCE.
The oil from original rapeseed is high in Erucic acid, however. Erucic acid has been shown to be toxic in high doses in rats, so there was a desire to find or produce cultivars of rapeseed that didn’t have so much of it. Researchers at the University of Manitoba in Canada bred canola in the 1970s from a couple of varieties of rape, specifically looking for offspring with seeds low in Erucic acid. The name comes from “CANada Oil Low Acid.”
So the original canola was a product of plant breeding. There are also genetically modified varieties of Canola, probably most of what is grown in the US, that are resistant to glyphosphate AKA round-up, which is a herbicide that farmers use a lot. Glyphosphate works by poisoning an enzyme in plants that is important for amino acid synthesis. Glyphosphate resistance is introduced by giving the plants a bacterial version of that enzyme that isn’t poisoned by glyphosphate. I am a molecular biologist and I’m not afraid of most GMO crops (though there certainly are down sides to industrial production of seed and having the ability to soak your field in round-up which I will be happy to go into some other time.) If GMO crops bother you, you should be aware this same GMO enzyme is present in a lot of other crops, like soybeans, corn, sugar beets and wheat, so if you really want to avoid it you are going to have to go to some effort. Organic crops apparently can’t be GMO so organic canola would fit the bill. Be aware that it’s going to cost more.
Canola oil is produced by harvesting the seed, heating and crushing it (or sometimes just crushing it without heat), to remove about half the oil, then extracting with hexane to remove the rest. It’s possible the hexane is the source of my commenter’s alarm. The hexane-oil mix is separated from the rest of the crushed seed and the hexane is evaporated from the oil and re-condensed back at the starting point to be re-used for the next batch of seeds. This appears to be a pretty efficient process, (and it had better be, since hexane has a deeply unpleasant smell; instant headache, IMO.) This appears to be a standard method of extracting oil from “oilseeds” which include canola and rapeseed, but also peanut, sunflower, soybean, coconut and palm oil. If you are very concerned about hexane, look for “cold pressed” canola, which *should* be just the first half of the oil from the seed, before hexane makes an appearance. It will be more expensive than regular canola oil, since it’s not as efficiently harvested. Or, if you are really worried about it, olive oil is nearly as healthy and is extracted with water, so there’s that.
So though I use olive oil for most of my cooking, I’m going to continue to use canola for stuff where the olive oil flavor would be a problem, or where I need a higher smoke point. And if cost becomes a pressing issue again, canola is cheaper than olive oil and I will be going with that.
*rolls up sleeves*. Okay folks, let’s do this thing.
What is canola oil? I’ve never seen a canola, do you have to round them up like cattle, or pick them off trees like apples or dig them up like potatoes, or what? Are they really not food?
It all goes back to a plant with the inauspicious moniker of “rape,” from “rapum” the Latin name for, of all things, turnips. This is less weird than it sounds, because the plant belongs to the Brassicaceae family which includes cabbage, mustard and turnips, (honestly the family lineage reads like a particularly well-stocked grocery: cabbage, mustard, kale, broccoli, cauliflower, collards, Chinese cabbage, horseradish, radish and thale cress.)
The main point of this particular species is its pods and specifically the seeds inside, which are rich in oil. The seeds, and the meal produced by processing them for the oil, can be used for animal feed and the oil can be used for biodiesel production as well as cooking, and sometimes as a replacement for petroleum in non-food products like newspaper ink. Despite the modern uses, this plant has been cultivated for thousands of years, starting in India in 4000 BCE.
The oil from original rapeseed is high in Erucic acid, however. Erucic acid has been shown to be toxic in high doses in rats, so there was a desire to find or produce cultivars of rapeseed that didn’t have so much of it. Researchers at the University of Manitoba in Canada bred canola in the 1970s from a couple of varieties of rape, specifically looking for offspring with seeds low in Erucic acid. The name comes from “CANada Oil Low Acid.”
So the original canola was a product of plant breeding. There are also genetically modified varieties of Canola, probably most of what is grown in the US, that are resistant to glyphosphate AKA round-up, which is a herbicide that farmers use a lot. Glyphosphate works by poisoning an enzyme in plants that is important for amino acid synthesis. Glyphosphate resistance is introduced by giving the plants a bacterial version of that enzyme that isn’t poisoned by glyphosphate. I am a molecular biologist and I’m not afraid of most GMO crops (though there certainly are down sides to industrial production of seed and having the ability to soak your field in round-up which I will be happy to go into some other time.) If GMO crops bother you, you should be aware this same GMO enzyme is present in a lot of other crops, like soybeans, corn, sugar beets and wheat, so if you really want to avoid it you are going to have to go to some effort. Organic crops apparently can’t be GMO so organic canola would fit the bill. Be aware that it’s going to cost more.
Canola oil is produced by harvesting the seed, heating and crushing it (or sometimes just crushing it without heat), to remove about half the oil, then extracting with hexane to remove the rest. It’s possible the hexane is the source of my commenter’s alarm. The hexane-oil mix is separated from the rest of the crushed seed and the hexane is evaporated from the oil and re-condensed back at the starting point to be re-used for the next batch of seeds. This appears to be a pretty efficient process, (and it had better be, since hexane has a deeply unpleasant smell; instant headache, IMO.) This appears to be a standard method of extracting oil from “oilseeds” which include canola and rapeseed, but also peanut, sunflower, soybean, coconut and palm oil. If you are very concerned about hexane, look for “cold pressed” canola, which *should* be just the first half of the oil from the seed, before hexane makes an appearance. It will be more expensive than regular canola oil, since it’s not as efficiently harvested. Or, if you are really worried about it, olive oil is nearly as healthy and is extracted with water, so there’s that.
So though I use olive oil for most of my cooking, I’m going to continue to use canola for stuff where the olive oil flavor would be a problem, or where I need a higher smoke point. And if cost becomes a pressing issue again, canola is cheaper than olive oil and I will be going with that.