In his quest to discover what makes the world's rarest delicacies so appealing, Prof. Massimo Marcone has hiked through the Amazon, tasted cheese filled with tiny mites, and most recently, braved a giant moray eel in the Cayman Islands.

"It was vicious," the University of Guelph food scientist says of the eel.

The author of the new book, "Acquired Tastes: On the Trail of the World's Most Sought-After Delicacies," had travelled to the Caymans to learn more about the elusive spider fish, a fish that has poisonous spines and skin but whose flesh has become a delicacy. What he hadn't expected was his fisherman guide seeking out moray eels while trawling for spider fish.

"They had stuck this eel in an ice bath in the boat, and then all of a sudden, this seven-foot giant moray eel jumps right out of the container and is actually in the boat with me in it! I had to jump out to the bow," he says, remembering the eel's razor-sharp teeth.

"I was terrified."

Marcone didn't lose a limb that day. But he did gain insight into part of the reason moray eel is a delicacy in itself: the simple danger involved in capturing the food gives it "cool factor."

It's the same reason fugu fish, filled with a potentially fatal mycotoxin, is a delicacy, Marcone argues in his new book. Those who are willing to brave fugu earn unique bragging rights -- further fuelling the food's delicacy status.

Other foods, like the mite cheese, come with their own built-in fear factor – and ick factor. Mimolette mite cheese is deliberately infected with millions of mites during the ripening process. The mites bore tiny holes into the cheese, imparting it with a unique flavour, then continue to crawl all through the cheese even as it's eaten.

After travelling to France to find the caves where genuine mite cheese is made, Marcone took samples of the cheese home to his lab. He wanted to test the samples to find out if the mites -- long associated with allergies and asthma -- carried pathogens into the cheese.

He found that the grey powder on the cheese consisted of mites dead and alive, plus their eggs, moulted skin and feces.

And he found it all perfectly safe. Though the cheese cellars and the mites themselves might aggravate dust allergies or asthma, eating the cheese appears no more dangerous than a bowl of bacteria-filled yogurt.

Safe as it might be, mite cheese hasn't exactly caught on with the masses in the way a delicacy such as lobster has. Yet, Marcone notes, lobster wasn't always a delicacy; in fact it was once considered a garbage fish, the "cockroach of the sea."

"At one time, lobster was so abundant… native Indians would collect them right off the shore, as storms would bring them in. And they would find very large one -- like 25lb lobsters," Marcone recounts.

"Because it was so readily available, lobster was what they would feed prisoners," he says. "It got to the point that there was a law passed that said that lobster couldn't be fed to prisoners more than twice a week, because it was considered inhumane."

How things have changed. It's precisely because lobsters are so rare that they have achieved delicacy status, as simple supply-and-demand economics have sent the price of the crustacean soaring.

Supply and demand also explains why foods once considered delicacies are delicacies no longer: coffee, teas, chocolate, maple syrup were once all so hard to come by, only royalty consumed them. That gave the items a certain cachet for the rest of the masses, who could only dream about trying them.

Marcone argues it's often the status symbol of delicacies that makes them so appealing -- and perhaps even tastier than they'd otherwise be.

"A food delicacy is a food that induces pleasure, that pleasure being more psychological than physical," he writes in "Acquired Tastes."

So does that mean that many delicacies aren't so much delectable, as desirable?

Marcone thinks so. He points as an example to the exotic morel mushroom. There are two kinds: white and black, with the white morel being more highly prized because of its rarity.

"But if you do a blind taste panel and allow people to taste both, they prefer the black morel over the white," the professor reports. "But when you speak to people about mushrooms, they'll say the white morel tastes better."

Delicacies are about more than just taste, and they're certainly about more than just filling your belly. They're about the stories behind them. They're about the legendary pig that sniffed out that perfect truffle, the tiny crocus flower that produced that tiny gram of saffron, and that giant eel that nearly ripped off your arm -- but that sure made for a tasty dinner.