They found that those people who said cilantro tastes like soap share a common smell-receptor gene cluster called OR6A2. This gene cluster picks up the scent of aldehyde chemicals.
He added that some people are highly sensitive to a group of chemicals called aldehydes and specifically to (E)-2-alkenals and n-aldehydes , the culprits behind that unpleasant soapy taste.
Depending on ancestry, somewhere between 3% and 21% of the population associate it with unpleasant taste, including a combination of soap and vomit, or say that it is similar to the foul smelling odor emitted by stinkbugs.
One of those genes, OR6A2, encodes a receptor that is highly sensitive to aldehyde chemicals, which contribute to the flavour of coriander. This makes OR6A2 “a compelling candidate gene for the detection of the odours that give it its divisive flavour”, the researchers write.
"It is estimated that 4 to 14 percent of the U.S. population has this genetic variation, making cilantro taste like soap," says Chef Brooke Baevsky, a manager in product development at Freshly. "For everyone else, the leafy green tastes like a fresh herb."
In the 23andMe study, we found that 14-21 percent of people of East Asian, African, and Caucasian ancestry disliked cilantro while only 3-to-7 percent of those who identified as South Asian, Hispanic, or Middle Eastern disliked it.
These people have a variation in a group of olfactory-receptor genes that allows them to strongly perceive the soapy-flavored aldehydes in cilantro leaves. This genetic quirk is usually only found in a small percent of the population, though it varies geographically.
They found that those people who said cilantro tastes like soap share a common smell-receptor gene cluster called OR6A2. This gene cluster picks up the scent of aldehyde chemicals. Natural aldehyde chemicals are found in cilantro leaves, and those chemicals are also used during soapmaking.
Cilantro taste aversion is linked to a change in the OR6A2 gene. This is an olfactory receptor gene. Olfactory receptors are responsible for the sense of smell which affects taste also. People who do not like the taste of cilantro are found to have the CC genotype of SNP rs72921001 found in the OR6A2 gene.
If you can't stomach cilantro or other bitter foods such as cabbage, Brussels sprouts or arugula, you can blame your DNA. "Something as simple as … a really small change in your bitter receptor gene can actually influence how much you like to eat vegetables and how much you do eat vegetables," Hayes says.
The study found that there was a common genetic factor that regulated responses to spicy foods. The results revealed that genetic factors accounted for 18% to 58% of the variation in the enjoyment of spicy food, which allowed the researchers to conclude that spice tolerance does have ties to genetics.
It's in Your Genes
According to a genetic survey by researchers at Cornell University, there's a very specific gene that makes some people strongly dislike the taste of cilantro. After surveying nearly 30,000 people, the scientists singled it down to the OR6A2 gene.
Blame it on your genes — and your surroundings
One study noted a very specific genetic link near the olfactory center of DNA in about 10% of those with cilantro aversion. What's even more interesting, according to the study, women are more likely to detect a soapy taste and dislike cilantro.
Coriander (cilantro) leaves are used as a flavoring agent in varied cuisines. However, this popular herb has divided people into two camps—those who like it and those who do not. Coriander lovers say it has a fresh citrus taste with a strong aroma, while the haters say it has a soapy taste and a pungent smell.
Soap is loaded with essential oils that smell great, but it also has sodium based organic salts namely sodium dodecyl sulfate and cocamide diethanolamine, and a few others. These compounds are basic and because of that are bitter. But the sodium salts are not volatile therefore you do not smell them but do taste them.
Super-tasters have many more visible taste papillae than tasters and non-tasters. This is illustrated in the figure below. This means they have many more taste cells with receptors for bitter taste. Super-tasters are also more sensitive to sweet, salty and umami tastes, but to a lesser extent (10).
OR6A2 encodes olfactory receptor 6A2 (also abbreviated OR6A2). This is one of the receptor proteins that transmits smells from the nose to the brain [R]. The olfactory receptor gene family is enormous, with over 300 genes identified so far.
Cilantro haters are a vocal bunch (an estimated 4-14% of the population), so against the herb that they can't even bear the tiniest taste.
If you're interested in seeing whether you can get over your cilantro aversion, it's certainly possible. Just ask the neuroscientist in McGee's piece, who also happens to be an expert in smell. McGee notes that crushing cilantro may help eliminate its more soapy aroma substances.
Scientists think that it's possible to overcome the aversion. Bruising the herb through crushing, mincing, or pulverizing (like in this Spicy Parsley-Cilantro Sauce recipe) releases some of the soapy-tasting enzymes. Cooking cilantro—instead of eating it raw—is also thought to reduce the soapiness.
Acid reflux, cavities, oral thrush & dry mouth can all lead to this soapy flavor too. Medications & dietary supplements can also affect how you taste, so be sure to note any new prescriptions & diet when discussing this with your dentist. Finally, while it's not likely, a soapy taste may be the result of poisoning.
As many as one in five people says that coriander has a soapy taste. This is likely to be due to a super-sensitivity to chemicals called aldehydes, which are present in coriander and are also used to perfume soaps and detergents.
Diseases associated with OR6A2 include Retinitis Pigmentosa 24 and Retinitis Pigmentosa 3. Among its related pathways are Olfactory Signaling Pathway and Class A/1 (Rhodopsin-like receptors). Gene Ontology (GO) annotations related to this gene include G protein-coupled receptor activity and olfactory receptor activity.