Apparently, not all premium chocolate is actually premium, like wine, expensive, premium product can be mixed with a more common variety to be sold at the higher, premium price.  Now, scientists in a collaboration which spans the US, China, and Trinidad and Tobago have found a way to authenticate premium chocolate according to a Jan. 15, 2014 news release on EurekAlert,

For some people, nothing can top a morsel of luxuriously rich, premium chocolate. But until now, other than depending on their taste buds, chocolate connoisseurs had no way of knowing whether they were getting what they paid for. In ACS’ Journal of Agricultural and Food Chemistry, scientists are reporting, for the first time, a method to authenticate the varietal purity and origin of cacao beans, the source of chocolate’s main ingredient, cocoa.

Dapeng Zhang and colleagues note that lower-quality cacao beans often get mixed in with premium varieties on their way to becoming chocolate bars, truffles, sauces and liqueurs. But the stakes for policing the chocolate industry are high. It’s a multi-billion dollar global enterprise, and in some places, it’s as much art as business. There’s also a conservation angle to knowing whether products are truly what confectioners claim them to be. The ability to authenticate premium and rare varieties would encourage growers to maintain cacao biodiversity rather than depend on the most abundant and easiest to grow trees. Researchers have found ways to verify through genetic testing the authenticity of many other crops, including cereals, fruits, olives, tea and coffee, but those methods aren’t suitable for cacao beans. Zhang’s team wanted to address this challenge.

Applying the most recent developments in cacao genomics, they were able to identify a small set of DNA markers called SNPs (pronounced “snips”) that make up unique fingerprints of different cacao species. The technique works on single cacao beans and can be scaled up to handle large samples quickly. “To our knowledge, this is the first authentication study in cacao using molecular markers,” the researchers state.

Here’s an image, provided by the researchers, illustrating their work,

Here’s a link to and a citation for the paper,

Accurate Determination of Genetic Identity for a Single Cacao Bean, Using Molecular Markers with a Nanofluidic System, Ensures Cocoa Authentication by Wanping Fang, Lyndel W. Meinhardt, Sue Mischke, Cláudia M. Bellato, Lambert Motilal, and Dapeng Zhang. J. Agric. Food Chem., 2014, 62 (2), pp 481–487 DOI: 10.1021/jf404402v Publication Date (Web): December 19, 2013
Copyright © 2013 American Chemical Society

This story reminded me that coffee too is sold at premium prices. Billed as the most expensive coffee in the world, Kopi Luwak, is harvested, so they say, from civet excrement and I have to wonder how anyone could authenticate that a bean had actually passed through a civet’s gastrointestinal tract and out the other end. I’ve also wondered how the practice of plucking coffee beans from civet excrement started (from the Kopi Luwak Wikipedia essay; Note: Links have been removed) here’s an answer to the second question,

The origin of kopi luwak is closely connected with the history of coffee production in Indonesia. In the early 18th century the Dutch established the cash-crop coffee plantations in their colony in the Dutch East Indies islands of Java and Sumatra, including Arabica coffee introduced from Yemen. During the era of Cultuurstelsel (1830—1870), the Dutch prohibited the native farmers and plantation workers from picking coffee fruits for their own use. Still, the native farmers wanted to have a taste of the famed coffee beverage. Soon, the natives learned that certain species of musang or luwak (Asian Palm Civet) consumed the coffee fruits, yet they left the coffee seeds undigested in their droppings. The natives collected these luwaks’ coffee seed droppings, then cleaned, roasted and ground them to make their own coffee beverage.[11] The fame of aromatic civet coffee spread from locals to Dutch plantation owners and soon became their favourite, yet because of its rarity and unusual process, the civet coffee was expensive even during the colonial era.[citation needed]

I guess that in the future when you eat premium chocolate you can be sure that you’ve gotten what you paid for. As for coffee, I’m sure that industry is working on its authentication processes too and in the meantime, you’ll have to rely on your palate.