People, I'm sorry to break it to you, but there are just no two ways about it: Truffle oil (or truffled oil) is a sham, it's bad for you and it's just downright evil.
I'm currently traveling in Italy, where the world's most famous truffles are foraged. When I received an e-mail from my editor here at Eating...Our Words asking me if I'd like to share my thoughts on the big bowl of wrong that is truffle oil, I stopped at one of Italy's famous roadside Autogrill franchises and picked up the above bottle of this pernicious pseudo-food product for edification's sake.
The fact that truffle oil is made with 2,4-Dithiapentane (a petroleum product) and not with truffles has been widely documented in contemporary gastronomy. (See this celebrity chef's abjuration of truffle oil published in 2007 by The New York Times, "Hocus-Pocus, and a Beaker of Truffles.")
"Prepared by the acid catalyzed addition of methyl mercaptan to formaldehyde" (according to the Wiki entry), 2,4-Dithiapentane chemically reproduces the aroma of truffles. If you've ever smelled mercaptans, you know that they smell like farts. So if you want to consume olive oil that's been infused with fart aroma and one of the most toxic substances commonly used by humankind, I can only say de gustibus non est disputandum.
You'll note in the above detail of the label that the ingredients include "truffle aroma" and olive oil. But if you look carefully at the front label of the bottle, you see that it depicts white truffles from Alba (Piedmont, Italy) with the caveat that "the image is not representative of the contents." By law, the producer is required to write that because it doesn't contain truffles!
But beyond the fact that truffle oil is an entirely duplicitous and unwholesome pseudo-food product, there is another and equally important reason why it should be avoided.
Whether black from central Italy (most famously Umbria) or southern France or white from Alba (northwestern Italy), truffles are among the world's most expensive and coveted foods, often costing thousands of dollars per pound (depending on their pedigree and market demand).
The snake-oil salespeople who hawk truffle oil play on the bourgeoisie's tireless desire to obtain out-of-reach luxury products and the social status that they bring. There's something about truffles that makes them supreme among consumer goods in their capacity -- like caviar or Champagne -- to make people feel rich. The very notion of truffle-infused oil is a perversion of one of the world's greatest (and, many would say, sublime) sensorial experiences. And it represents a subjugation of the human spirit and condition. In other words, it's just plain ideologically wrong. I would even go as far as to say evil.
Don't waste your time and palate with french fries doused in a petroleum product. Go to one of the handful of Houston restaurants that know how to properly store and serve truffles and splurge on a plate of risotto or scrambled eggs topped with two or three truffle shavings. It may set you back $100 or so, but -- if they're stored and served correctly -- you'll find the experience to be truly priceless.
See the Wiki entry for truffles for some background on the "diamond of the kitchen."