Say you buy a $45 box of chocolate. You're going to want that chocolate to be worth $45. It should be pretty fancy chocolate. But, up until now, anyone who wanted to determine the authenticity of a high-end piece of chocolate had to rely on taste. If your $45 box of chocolate tasted a bit off, there was no way to prove or disprove its authenticity. But, now, a new sleuthing technique provides chocolate fanatics with a way to find their chocolate's true identity.
Just look at the beans' genes.
"One problem with the premium cacao market is contamination with off-types adulterating raw premium material," researchers who developed the new technqiue write in a paper. "Adulteration may be intentional or unintentional."
Whereas other industries—fruits, olives, tea and coffee—already use DNA-based methods that guarantee that their products are indeed what their labels claim, chocolate has been left out. This is partly due to chocolate's complexity: because adulteration depends on whether different strains of cacao seeds are mixed together, DNA needs to come from a single cacao seed in order to authenticate it, which can prove challenging.
To get around this, the researchers sought out single-nucleotide polymorphisms (SNPs), or short DNA chains that differ between closely related species. They idenfitied SNPs from the major cacao species, which can serve as molecular markers for quickly determining whether cacao comes from a humble cheapo strain or a top-of-the-line variety. The new method can be quickly applied to large samples, they add.
"This approach is robust for authentication verification of gourmet cacao varieties and, thus, has significant potential for practical application," the team concludes.