Coriander leaves (Coriandrum sativum), also known as Cilantro, arouse strong emotions.  Eaters are divided into those who find the flavour citrusy, fresh and pleasant against those who insist it is soapy, dirty and foul.

A genetic role has long been suspected, from previous studies published in Flavour and other journals.  Mauer and El-Sohemy showed that between 3 and 21% of Canadians disliked cilantro, depending on their ethnic group.  Now researchers have found a single nucleotide polymorphism (SNP) which appears to control this dislike and which is published today in Flavour.

This genome-wide association study was carried out by genomics company 23andme, which has pioneered personal genome sequencing.  They tested 14,604 participants of European descent who disliked cilantro, together with 11,851 who liked the herb.  They found a SNP, rs72921001, which was significantly associated with soapy-taste detection.  Intriguingly, the mutation lies within a cluster of olfactory receptor genes, including OR6A2, which is known to bind the aldehydes that give cilantro its flavour.

‘These results confirm that there is a genetic component to cilantro taste perception and suggest that cilantro dislike may stem from genetic variants in olfactory receptors,’  the team said.  ‘We propose that OR6A2 may be the olfactory receptor that contributes to the detection of a soapy smell from cilantro in European populations.’

The study is published as part of a series on the Genetics and Neuroscience of Flavour, edited by Danielle Reed, Monell Chemical Senses Center and Richard Newcomb, University of Auckland.