The burgers at the Cherry Hut restaurant in Beulah, Mich., are a hit with customers. But these aren't ordinary hamburgers. Every summer, when tourists come to sample the state's bumper crop of cherries, the restaurant's co-owner Andy Case starts taking orders for the restaurant's popular burger. After broiling the patties in the kitchen, he slides them onto a bun and tops them with fixings. It's in this moment, before the first bite, that customers stir with anticipation because the Cherry Hut is home to an unlikely specialty – the cherry burger.

The burgers are filled with tart, or sour, cherries grown in northern Michigan – the cherry capital of the world.

Although people come to the Cherry Hut for the restaurant's cherry pies, the cherry burger has become a popular seller and a conversation starter. Mr. Case says he probably sells more cherry burgers than regular burgers. "People want to be more health conscious," he says. The cherry burger is "tasty, juicy, healthier."

A burger fit for Oprah

Adding cherries to burgers may seem a bit odd, but mixing tangy or sweet fruit with ground beef or poultry to form patties is becoming more common.

Donald Trump's restaurants – the Mar-a-Lago Club in Palm Beach, Fla., Sixteen in Chicago, and the Trump Bar and Grill at Trump Tower in New York – serve up the Mar-a-Lago turkey burger stuffed with diced Granny Smith apples and Major Grey's chutney and topped with an Anjou pear chutney that contains raisins or currants.

It's even turning the heads of celebrities. On her daytime talk show, Oprah said the Mar-a-Lago turkey burger "may be the best turkey burger in the entire world."

Ever since, the recipe has received praise on Internet message boards. For Jeff O'Neill, executive chef at the Mar-a-Lago Club and the creator of this acclaimed burger, it's been a "humbling" experience.

But his reason for creating this burger was simple. "I never had a turkey burger that was good," Mr. O'Neill says. Usually, "they are dry. They're plain. I wanted to have a burger that was juicy, flavorful, and refreshing all on its own."

So O'Neill turned to fruit. Inspired by a classic Thanksgiving combination – cranberries with turkey – and Palm Beach's warm weather, he created a club favorite. The apples provide a crisp, refreshing bite, and the chutney purée helps keep the patty moist, he says.

The benefits of adding fruit to burgers

Mixing fruit into burgers to add moisture is a big reason to do it, says James McNair, a cookbook author and head judge of the Sutter Home Family Vineyards Build a Better Burger (BBB) contest in St. Helena, Calif.

Since 1990, Mr. McNair has been tasting and testing thousands of burger recipes from aspiring cooks. Lately, he's been noticing how often fruit sneaks its way into contest entries. Last year, apples – diced and grated – as well as dried and fresh cherries and raisins were a common theme.

Tropical fruits also made an appearance. The 2008 grand-prize winner's burger featured papaya. The Hawaiian-themed burger was topped with papaya, avocado, and watercress, but the fresh papaya mixed in the ground-beef patty made all the difference.

"The papaya enzymes are supposedly enzymes for the meat," McNair says. "It sure made a juicy, delicious patty."

The art of creating a moist burger depends not only in the chosen ingredients, but the cooking time on the grill, he mentions. "A lot of people have a tendency to overcook burgers and dry them out." But adding "fruit helps with that. Plus, it adds nutrition."

Middle Eastern cuisine often includes fruit. Dates, apricots, and figs are common ingredients. The savory-sweet combination is commonly found in Moroccan tagines. In 2005, it showed up in the BBB contest's winning burger, which featured dried apricots and dates in a flavorful burger.

Adding fruit to burgers "adds a little moisture and a nice texture and a little sweetness." McNair says. "And I think people are trying to get more fruits and vegetables into their diet."

Although you may not readily find a fruit burger on most restaurant menus, McNair says, that's no reason they won't start gaining interest from home cooks. "We're sort of ... starting the home trend [now]. I think home cooks are more adventuresome than chefs."

An Internet search turns up fruit burger recipes from amateur chefs featuring everything from pineapple to prunes.

Cookbook author Linda Dannenberg traces her fruit burger inspiration back to childhood. She grew up in Newton, Mass., where a favorite food was blueberry muffins topped with crusted sugar, a recipe from the Jordan Marsh department store.

This led to her trying many other ways to use blueberries. As an adult, she collected her favorites into a book of blueberry recipes, "True Blueberry," which includes directions for making blueberry salsa and a blueberry burger.

The taste of Ms. Dannenberg's blueberry burger – a combination of beef and ground-up, freeze-dried blueberries – surprised even her husband and 21-year-old son, who were hesitant to try the burger at first.

"Neither of them were enthusiastic about ... blueberries in a burger," she says. But the subtle, slightly sweet flavor changed their minds.

Adding fruit to meat isn't a weekly occurrence at the Dannenberg household, but she occasionally makes a cranberry turkey meatloaf loaded with a cup of dried cranberries.

"It's the acidity that's a nice complement to the richness of the beef," she says.

Home cooks who are doubtful about stuffing a burger with fruit might want to try glazing burgers with jam, marmalade, or various chutneys, which form a sweet, "very nice exterior glossy, tasty finish," says McNair, who occasionally cooks up his own fruit burgers at home.

Fruit burgers at school

Outside the home, fruit burgers are making an appearance in school cafeterias. Several years ago, two or three Texas schools served blueberry burgers on a trial basis, according to Al Bushway, professor of food science at the University of Maine.

More recently, the University of Maine has been conducting research for a soy-based veggie burger made with blueberry purée, which they hope to market to the general public.

Cherry burgers have also made their way into the school lunch system. In Cedar, Mich., Ray Pleva, a butcher, has been selling cherry-meat products since February 1988. Recently, he's been distributing cherry burgers to more than 400 schools across the US. And like the Mar-a-Lago burger, Mr. Pleva's cherry burger has appeared on the Oprah show.

The spark to start his business came after his daughter won a National Cherry Queen Competition. To help bolster the cherry industry, he created his unique line of cherry-based products.

His company adds a cherry powder, made from ground-up tart cherries, to 91 percent lean, ground sirloin. The powder is easier to distribute in the burgers than cherries themselves. He touts the nutritional value of the burgers as well as the added moisture. Adding cherries also doubles the shelf life, Pleva says.

Whether you add dried or fresh fruit, blueberries or apples, fruit burgers are on the cutting edge. Currently, restaurant menus are touting gourmet burgers made from prized Kobe beef, ground brisket, or meat from short ribs.

Who knows? Perhaps fruit burgers will be next.