Building a better strawberry

NCSU scientists team with Johnson & Wales chefs to create the tastiest fruit

CorrespondentJune 27, 2011 

  • Jeremy Pattison

    Age: 36.

    Title: Strawberry breeder and assistant professor, Plants for Human Health Institute, North Carolina Research Campus, Kannapolis.

    Home: Faith

    Family: Wife, Heidi Pattison; sons Conlyn, Logan, Liam and Braedon.

    Prize-winning recipes

    Try out strawberry recipes from Johnson & Wales University students.

Expert taste tester Judy Heylmun plucks a ripe, red strawberry from a plate, takes a bite, and pauses to let the taste register on her tongue.

"I give it a nine on the sweetness scale," she says.

Another taste tester bites into a berry, puckers, and writes "astringent" on her chart.

The taste testers belong to a team hired in May as part of the N.C. Strawberry Project, a partnership between N.C. State University's Plants for Human Health Institute - located at the North Carolina Research Campus in Kannapolis - and Johnson & Wales University in Charlotte.

Their task: to tease out subtle differences in flavor and appearance between one strawberry and another.

Watching through an observation window in an adjacent room, project director and N.C. State researcher Jeremy Pattison plans to use their results in his efforts to breed a tastier, hardier North Carolina strawberry.

Pattison also hopes to hold strawberry taste tests with produce buyers and chefs to find out what each group looks for in an ideal berry.

"The project is unique in the plant breeding world in that we're asking the culinary industry to help us define what makes for the tastiest fruit," he says.

Pattison scrolls down a list of some of the major compounds that give strawberries their distinctive taste.

"Strawberry flavor and aroma come from a complex mixture of more than 300 compounds," he says.

Volatile esters, lactones and other natural compounds form as the fruit ripens, producing flavor notes reminiscent of coconut, pineapple and caramel.

"This one tastes like cotton candy," says Pattison, pointing to a compound labeled "ethyl maltol." "It's a pretty strong note in strawberries, especially berries from California."

"Other varieties have a strong grape Kool-Aid flavor."

Comparing textures

The taste testers are seated around a table spread with other foods most of us are unlikely to associate with strawberries. As benchmarks for texture, they compare the berries to crisp apple slices, crunchy carrots, soft cheese and chewy nougat.

Pattison points to a tray of potato chips. "They're useful for describing mouth feel," he explains. "When you bite into a strawberry, does it immediately dissolve on the tongue like a potato chip, or does it stick around?"

Plastic cups containing sugar and acid solutions in increasing concentrations serve as reference points for basic tastes such as sweet and sour.

"Each solution represents a standard on a 15-point scale," Pattison explains.

The panelists work their way through nearly 20 varieties, noting their ratings for taste, texture and shape on their data sheets as they go.

Following intently, Pattison leafs through a small notebook with the names of the varieties scrawled by hand - the Chandler from California, the fraise des bois from France, and other varieties from berry breeding programs at N.C. State and other universities.

The goal is to pick the perfect parents for the next generation of strawberries, Pattison says.

"Then we can ask, based on what our taste testers like and dislike: Which variety is in that category? Most likely it will be one that's not adapted to North Carolina. But it's a potential parent in our breeding program," he says.

Once he's identified the perfect mates, Pattison will do the work of bees and transfer pollen from blossom to blossom to combine the most desirable traits through cross-breeding.

Growing berries in N.C.

Pattison leads the way to a strawberry field at the Piedmont Research Station near Salisbury, where the berries from the afternoon's taste test were picked earlier that morning.

Tidy rows of strawberry plants stretch to the horizon, drooping under their load of ripe fruit.

The ideal strawberry means different things to different people, Pattison says.

A chef, for example, may want a redder, sweeter berry; a farmer may want a berry that resists attack by fungal pathogens and insect pests; a produce buyer may want longer shelf life.

Pattison kneels down amid the rows and gently squeezes a berry to gauge its firmness - a good quality for packing and shipping.

"We've got 8,000 one-of-a-kind strawberry plants out here, and we've got to find out what's special about each one," he says.

North Carolina produces more than 19 million pounds of strawberries each year, making the state fourth in the nation in strawberry production, behind California, Florida and Oregon.

"The three main strawberry varieties currently grown in North Carolina were originally bred for climate conditions in California and Florida," Pattison says.

Strawberries may be sold in supermarkets year round, but North Carolina-grown berries are only available for four to six weeks a year, beginning in late April in the Eastern part of the state and extending through late May in the mountains.

To make locally grown strawberries available for a longer period, the key is to breed a berry more suitable for the state's climate, Pattison says.

It may still take 10 years or more before Pattison brings the first fruits to market.

But chef Mark Allison of Johnson & Wales University in Charlotte won't be waiting around.

Since the North Carolina Strawberry Project launched last September, Allison's students have been busy developing dishes featuring locally grown strawberries as a main ingredient.

Student finalists in the Johnson & Wales strawberry cook-off series walked away with $500 and $1,000 scholarships provided by the Golden LEAF Foundation, a main supporter of the project.

The winning recipes include grilled swordfish with strawberry-cucumber salsa, strawberry and shrimp ceviche, and a gluten-free strawberry tart.

"The project has been instrumental in educating our student chefs about the benefits of buying locally-grown food," Allison says.

Back at the Piedmont Research Station, Pattison kneels down and picks a ripe strawberry from the vine.

"Tasting every berry in this field would be a recipe for bellyache," he says. "But it's awfully tempting."

robinsmith.sciwriter@gmail.com

News & Observer is pleased to provide this opportunity to share information, experiences and observations about what's in the news. Some of the comments may be reprinted elsewhere in the site or in the newspaper. We encourage lively, open debate on the issues of the day, and ask that you refrain from profanity, hate speech, personal comments and remarks that are off point. Thank you for taking the time to offer your thoughts.

Commenting FAQs | Terms of Service