The latest trend in fine dining kitchens in the US is the use of sea buckthorn berries as a menu ingredient.

In upscale cocktail bars and specialty food magazines, the Japanese fruit yuzu is fast becoming a pet favorite.

And tamarind, a sweet and sour fruit used in Worcestershire sauce and common in Southeast Asian and Indian foods, has started creeping up in mainstream chain restaurants.

All of these trends point to an American palate that enjoys being challenged by "extreme and edgy" flavors, says a new report from the Center for Culinary Development, CCD, and market research group Packaged Facts.

But they also illustrate the chain of command and how flavors that start off as new, fringe ingredients become picked up as novelty items along the way, until reaching mainstream diners through chain restaurants, points out online trade magazine,

New trends will often start out in fine dining establishments, where audacious chefs with an adventurous streak will turn their kitchens into experimental labs. The report singled out the sea buckthorn fruit - a hardy, orange berry which is acidic and bitter raw - as the latest ingredient to excite bold and intrepid chefs.

Sea buckthorn-based juice is popular in Germany and Scandinavian countries. The Danes have a Schnapps recipe that uses the berry as flavoring, and it's also used to make pies, jams and even beauty products.

Yuzu, which tastes like a cross between a grapefruit and a sour mandarin, has reached a wider culinary audience thanks to the proliferation of Japanese cuisine and its application in Asian kitchens. But it remains a specialty food item available only in ethnic food stores.

The tamarind, however, is another story. What used to be an obscure, ethnic ingredient has reached the mainstream diner with appearances on franchise restaurant menus.

The next step in the food ingredient life cycle, would be for it to appear in family-oriented consumer magazines and grocery store shelves or quick service restaurants - not unlike wasabi and the combination of chocolate and chili, the report said.

What used to be considered an unusual pairing of flavors, for instance, has now become so commonplace that cocoa and chili chocolate bars are sold on supermarket shelves. Swiss chocolate maker Lindt, for instance, has an Excellence Chili bar that combines rich dark chocolate with the heat of premium chili.

Likewise, wasabi has migrated entirely into the mainstream, the report added, and can now be found in dishes like mashed potatoes, hummus, aioli, dressings and chocolate.

"Consumers around the globe are thrilling to new, bigger, bolder flavors and unique flavor combinations," Kimberley Egan, CEO of the culinary center told Foodnavigator. "Our palates are being pushed in all kinds of sweet, salty, sour and bitter directions, while new flavors tempt us from the edge of the culinary ingredient spectrum."

The report also pointed out that different markets interpret new flavors differently. Young men, for instance, are in it for "a big kick," women for the possible health benefits, and Latinos and Asians for the "familiar flavors in new places." Everyone, however, seems to enjoy the rounder, more balanced tastes new flavor profiles offer.