Tasty 'black diamonds' truffling into the culinary world

Nicknamed ‘diamonds’ of the culinary world, fungi delicacies known as truffles are prized for their unique flavour and scent. But newer truffle species are now entering the market and fighting to achieve that same gourmet status. Researchers reporting in ACS Omega have studied the aroma of the Appalachian truffle to determine the potential for a new North American ‘black diamond’.

Truffles are subterranean fungi of the Tuber species that require several years under particular conditions to grow. Determining the best way to cultivate the fungi has been difficult, so most forage for them using trained animals, such as pigs or dogs. And because truffles are so rare and challenging to obtain, they are very expensive. For example, a large 1.5 kg behemoth from Italy cost US$330,000 at auction several years ago. Commercial truffles most often originate from Europe, Australia and the western US, but different species exist all over the world. Unlike the fancy white or black truffles grown in Italy or France, however, many unearthed in North America have not been well studied. So, Normand Voyer and colleagues wanted to thoroughly analyse the aromatic profile of one of these North American varieties, known as Tuber canaliculatum, or Appalachian truffle.

Appalachian truffle. Image credit: David Fortier

To accomplish this, the researchers investigated three T. canaliculatum samples using headspace solid-phase microextraction (HS-SPME) and gas chromatography-mass spectrometry (GC/MS). With these techniques, the team identified the species’ ‘volatilome’, or the chemical fingerprint responsible for its aroma. A total of 30 different compounds, including six that had never been reported in other truffle species, were identified. Some, such as 2,4-dithiapentane, are found in many truffle species and give truffle oil its unique smell. The most prevalent compounds were described as having strong odours of garlic, fungus and even a cabbage-like, rotten smell that was found in higher concentrations in older samples. The researchers say that this work could spur future studies of T. canaliculatum, which might one day place it at the same high status as its European cousins.

Top image credit: iStock.com/Seven