Cyanide in Cherries: Pt II

by on November 05, 2011

In part one we figured out how much cyanide was contained in fruit pit kernels and their toxicity. To summarize, yes there is cyanide in the kernels and there is enough to harm you. The next obvious question is; can you remove the cyanide from the kernel so it can be used in liqueurs? Additionally, I know that at some point in time I will receive angry emails from advocates of amygdalin (laetrile) who will swear that eating stone fruit pits is good for you. Now, everyone is basically free to do whatever they want, except my North Korean readership, so I will just present the facts and let you decide.

Let's start with removing the cyanide. There is a chemical process that can be used, but it still requires distillation. Hydrogen cyanide can be freed from water by shaking it with milk of lime (calcium hydroxide); all the hydrocyanic acid, both free and combined, will form calcium cyanide. Adding ferrous sulphate will convert the calcium cyanide into calcium ferrocyanide, which binds up the cyanide and makes it only mildly toxic. The problem is that you wouldn't want to drink  this as it doesn't taste very good. This solution would be distilled and the benzaldehyde (oil of bitter almond) would be obtained free from cyanide. This is the process that oil of bitter almond manufacturers probably use.

Why go to all this trouble when you can just buy oil of bitter almond. Oh ya, everyone wants "all natural" stuff.  The reality is that the flavour people are looking for is benzaldehyde and that's exactly what oil of bitter almond is, sans the cyanide or amygdalin. Regardless of whether benzaldehyde is made by dwarf Albanian artisan distillers who crack each kernel with their armpit or made using that black art called chemistry, it is the same stuff. Here's a question to chew on: is the ethanol in distilled spirits natural or synthetic?

Since the distillation method isn't practical for the average person here's another, though much slower, method—think months. Hydrogen cyanide can be hydrolyzed to formic acid and ammonia. Yes, formic acid the same stuff that fire ants use to piss you off. Hydrolization is done in the presence of water, so if you just infuse apricot kernels in vodka, some of the hydrogen cyanide will decompose, but the process is very slow. Heat will help. It should also be noted that formic acid has a fruity, mustard aroma.

Okay, I understand you are impatient so here is one more method. A number of sources have indicated that roasting the kernels at 176°C (350°F) for 10 to 15 minutes will drive off the hydrogen cyanide. This could work, but you have to make sure the kernels are free from the shell and ground coarsely. I'd recommend adding enough water to make a wet mass and set aside for an hour or more to ensure that the amygdalin and beta-d-glucosidase enzyme can react.  Afterwards, spread the mixture out on a baking sheet and heat until dry.

There is no guarantee that this method will remove all the cyanide, but it should remove some. "Dry roasting" is not effective since amygdalin is stable at that temperature. Also, the boiling point of benzaldehyde is 178°C, which is just 2° higher than the cooking temperature, so you will most likely drive off some of the flavour component you are trying to capture.

Cyanide Toxicity

Long term cyanide exposure may result in neurological disorders and thyroid abnormalities. The longer term effects have been well documented in African and Western Pacific communities where cassava root is a staple food. Konzo, ataxic polyneuropathy and amyotrophic lateral sclerosis (ALS) are some of the neurodegenerative disorders that are associated with long term consumption of cyanide contain foods. Give something a scary name like ataxic polyneuropathy and people will think twice about trying it. However, a tiki cocktail named Konzo might be interesting.

If you lack discipline and really, really need to make something with fruit kernels—pick up a bottle of hydroxocobalamin (Vitamin B12) at your local food store for a few bucks. Hydroxocobalamin actually scavenges cyanide from your system, and readily converts from the hydroxy form to the cyanocobalamin form when it encounters cyanide. Consider it a prophylaxis.


Since we are on the topic of amygdalin, let's bust a myth. Googling the term "apricot kernel" results in thousands of pages talking about their magical cancer curing properties because they contain amygdalin, sometimes called laetrile. So what's the deal? Is this legit or not? It is bullshit, and here is why.

First, the creator one Mr. Earnest T. Krebs Jr. was not a doctor, he received an honorary Ph.D from a defunct Christian Bible College in Tulsa, Oklahoma that was not accredited to award advanced degrees. His first real attempt at school resulted in him being expelled, but eventually he did receive a bachelors in Art, not medicine.

The development of this cancer curing idea occurred during the hay-day of pharmaceutical snake-oils in the late 1800s and early 1900s. Remember, this was a time when doctors would prescribe opium drops for babies with colic, heroin for coughs and bronchitis and strychnine as a nerve food. Seriously, Heroin was a Bayer product and strychnine was in many products, one called Hematone.

One of the reasons that this specific snake oil has stuck around for so long is due to some shrewd marketing. Instead of referring to it by its chemical name, they called it Vitamin B17. In reality, there is no such thing as Vitamin B17, it's just some smart marketing.

There is abundant clinical research that has disproved the cancer curing effect of amygdalin. One of the tell-tale signs that this product is bunk is that the advocates will always nitpick to the nth degree on the science that is used to disprove the claims, however these same advocates will never present any real scientific proof of their claims. I said science, not second hand information from your cousins boyfriends great aunts housekeeper.

Some of the laetrile advocates claim there is a conspiracy where the government keeps this supposedly cheap cancer cure suppressed because politicians are in the pockets of the big pharmaceutical companies. That would be all well and good if the United States was the only country on the planet, but alas they are not. Countries like Canada have a public healthcare system and that includes price controls on medicine. That's right, if you sell a prescription pharmaceutical in Canada the government will tell you how much you can sell it for, because it comes out of the tax payers purse. I'm sure a few conservatives are aghast, but the pharmaceutical industry is doing just fine and people don't have to choose between being homeless or alive.

Anyway, healthcare costs are significant in publicly funded healthcare countries like Canada and if curing cancer was as simple as eating apricot kernels they'd be shoving them down our throat or making us eat cereals called Captain Kernels or Kernel Smacks . The problem is that they can't, because it doesn't work.

Additionally, I actually work in a medical research facility and I have never witnessed a covert meeting where the researchers try to suppress successful medical developments. This would be rather career limiting since grant funding would dry up pretty quickly if these researchers weren't making discoveries.

The big problems is the lack of access to real research. Googling something does not make it true, nor does it qualify as research. Search engines are a popularity contest and have nothing to do with reality or science. If you want real research you can check out Pubmed or PloS.

And finally if that isn't enough to convince you, the fact that so many of the website promoting amygdalin as a cure for cancer use the Comic Sans font or make statements like "most pure" should be the final nails in their coffin.

To summarize, buying a bottle of commercial oil of bitter almond is the easiest way to get that bitter almond flavour and amygdalin as a cancer cure is bunk.

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