Why are "black diamond" truffles worth $900 per pound?

The black Périgord truffle, revered among foodies for its unique scent, has become so rare that it sells for $900 per pound. But not for long. A team of chemists have begun to reverse engineer the secret of its rare scent, and could one day flood the gourmet market with cheap replacement proteins.

Périgord is a black diamond among fungi — it only grows on oak and hazelnut roots, and as the researchers say in a paper published last week, nobody understands the truffles' symbiotic relationship well enough to farm it. So it has to be found in the wild, which is becoming increasingly difficult due to habitat changes and invasive species. Still, the truffle is revered among foodies for its smooth texture and complex, earthy aroma. A small amount, slipped into a dish, can transform the flavor.

But what makes that flavor so complex and desirable? It all has to do with the fungus' scent, which the team of researchers analyzed by looking at both the truffle's genome and its proteome — the complex of proteins it produces that govern everything from odor to shape.

The American Chemical Society describes what the researchers found when it came to smell:

They found that more than 2,500 proteins out of the truffle's nearly 13,000 were similar to existing proteins in other fungi, and they identified nine proteins that contribute to the cherished aroma. "This study has resulted in the functional characterization of novel proteins to increase our biological understanding of this organism and uncovered biomarkers of authenticity, freshness and perfume maturation," the scientists state.

The researchers compared the proteins they'd found with a few synthetic compounds on the market that are used to imitate the Périgord scent, and found some similarities. But now, would-be truffle reverse-engineers have a lot more to go on if they want to craft the perfect replacement for Périgord oil, or even Périgords themselves. The researchers caution that they are a long way from fully understanding the fungus' unique properties, but they are certainly on the way.

And yes, this study was partially funded by a truffle company. Fungus science conspiracy!

Read the full study in the Journal of Proteome Research