UF leads way in building better blueberry

Headline Goes Here Doug Finger/The Gainesville Sun

Matthew Peeler fills cups with blueberries during a taste panel at Building 120 on the University of Florida campus on April 8.

GAINESVILLE, Fla. (AP) - At the Flavors of Florida -- a cornucopia of science-enhanced produce, seafood and meat recently held at the University of Florida president's mansion -- the blueberries stood out, not only for their eye-popping color but also their mouth-watering flavor.

Pureed "Kestrel" blueberries swirled through a lemon-lime canape topped off with vanilla ice cream. "Chickadee" blueberries dotted a "limone" basil and tapioca parfait swirled with a strawberry liqueur and topped with a crunchy streusel.

Both varieties are the result of decades of painstaking research by University of Florida Institute of Food and Agricultural Sciences faculty and graduate students dedicated to figuring out how to build a better blueberry.

These aren't frankenberries, transgenic mutations altered by the insertion of genetic material of other organisms. The blueberries offered for public consumption are varieties produced the same way people have been cultivating plants for 14,000 years -- through selective breeding.

"This is good, old-fashioned plant sex," said Kevin Folta, chairman of the horticultural sciences department at UF and a professor of photobiology and strawberry genomics.

In fact, if it weren't for UF plant breeders, Florida's $75 million a year blueberry industry would not even exist.

"For the 32 years I've been in this industry, they've continued to make improvements and new varieties," said Alto Straughn, whose 750-acre blueberry farm in Alachua County is the largest producer in the state.

Without UF constantly improving and introducing new varieties, making money growing blueberries wouldn't be possible, he said.

For years, nearly three dozen plant breeders, biochemists, human sensory analysts, and geneticists at IFAS formed a loose association of colleagues devoted to building a better blueberry, among other things.

On March 23, the group officially became the Plant Innovation Center, led by Harry Klee, Linda Bartoshuk and David G. Clark. It will serve as an umbrella for other departments and centers at UF.

Many of these researchers have spent their careers devoted to research that will "change the future of food."

Klee's lab has been engaged for decades in exploring the science behind taste - what makes a tomato, melon or strawberry taste so good.

Clark, who founded the Floriculture Biotechnology and Genetics laboratory, is known for his innovative work in both basic and applied plant science, and for his ability to take new technologies to the consumer marketplace.

Bartoshuk, director of human research at UF and assistant director for the Center for Smell and Taste, is an international leader in taste research.

"These three people had the desire to turn plant breeding on its head to create healthy, good looking and really tasty plant varieties," said Jackie Burns, dean of research at IFAS. "They start with the consumer and work backwards to the underlying genetics and genomics."

Figuring out what humans like isn't easy. Identifying exactly what makes us like one type of strawberry or melon and not another is a long and tedious process.

Researchers present groups of people with different types of berries and ask them to rate them based on their own personal experiences. Scientists then try to isolate the compounds in the berries that produce the desired flavor, texture and other features by extracting the germplasm for further analysis and DNA mapping.

"We screen the germplasm for compounds that really make a difference," said Mike Schweiterman, a graduate student who walks around with strawberries in his pocket to give to people.

In this manner, UF scientists looked at 35 different strawberry varieties to isolate some 30 different compounds and volatiles connected to the flavor, aroma and other features people prefer in their strawberries.

The taste tests "help us decide what compounds we're looking for in new selections," said Jessica Gilbert, who is getting her doctoral degree in consumer assistance selection.

Hundreds of tests are conducted each year for UF horticulturists and researchers as well as private companies, said Sara Marshall, a biological scientist in the Food Science and Human Nutrition department at IFAS.

They are conducted in the Sensory Center in Building 120, a squat brick building tucked between the Marston Science Library and the IFAS quad on Newell Drive.

"We think we provide useful feedback about what consumers like best," food science professor Charlie Sims said.

The taste-testing lab (pictured) is a long narrow room of 10 booths separated by partitions. Each booth has a computer monitor and keyboard for consumer panelists to enter their impressions about the food they're tasting, as well as a tray with a glass of water and saltines to cleanse the palate between samples.

A sliding window allows student assistants to clear one tray and push the next sample at the panelists. The sliding panels serve another purpose -- they cut down on distractions, as loud and sharp noises can negatively affect grading and sensory testing. The dividers are there so people don't talk to each other and bias the group

Six different groups of panelists will come in over the next several hours and taste several varieties of blueberry that were recently harvested so they're fresh. Because blueberries ripen at different times, the researchers will do five or six sessions over several weeks to get the largest range of responses possible.

On this day, the researchers were tasting 25 different selected cultivars to see how each is perceived by a wide range of consumers with their own unique tastes.

This particular batch of blueberries was iffy, said Greg Allen, who works in Library Services and has participated in food tests for more than a decade. "I'm not really totally enthused, and I love blueberries," he said. "These are not sweet. Some are mealy and gritty."

That is the kind of information the researchers need in order to root out undesirable cultivars.

The taste panels help identify the compounds and volatiles that contribute to the qualities most pleasing to people's senses.

The survey data will be compiled and analyzed, and Gilbert will macerate the berries to extract compounds for analysis in the lab. She wants to isolate particular desirable compounds to target in the breeding program.

Gilbert will use the taste ratings from the panelists when she does the biochemical analysis in the lab, creating a huge data sets for each genotype. She will chart the sugars, acids, volatiles and other compounds extracting what panelists perceive as sweet or sour.

"We are looking for the right formula of everything," she said. "We target what we want to make it the best."

The blueberries grown commercially in Florida took four decades to produce.

In 1950, UF professor Ralph Sharpe began a low-chill breeding program, cross-breeding southern highbush blueberries with native Florida berry plants found around Winter Haven, creating a hybrid that could withstand the heat and humidity of the Sunshine State.

Wayne Sherman took over the program in the 1970s, hired Paul Lyrene, who developed the high-yielding cultivars that were sold commercially starting in the 1990s. Lyrene has patents on more than 30 blueberries bred specifically to withstand Florida's climate.

Today, about 90 percent of the cultivated commercially grown blueberries in Florida are the result of UF's breeding program.

Since 1992, the first year USDA tracked commercial blueberry growers in Florida, acreage has grown from 1,200 to 5,000. That is a lot less than the 20,000 acres of blueberries grown in Georgia, and a far cry from the 21,000 acres in the largest blueberry-growing state, Michigan.

But it's a huge step up from the days when Florida blueberry industry was dominated by mom-and-pop U-Pick fields.

That research has enabled growers like Straughn to expand from a 25-acre farm to 750 acres in 30 years.

UF researchers are now looking at how to make them more heat tolerant so they can grow in more southern ends of the state. Their goal is to address the "difficulty of producing a temperate adapted crop in a subtropical environment."

Jim Olmstead, assistant professor of blueberry breeding and genetics, is the fourth person to head up the UF blueberry breeding program. He coordinates his research with other UF scientists in different disciplines to address research issues together.

"I don't think we have come up with the perfect blueberry," Olmstead said.

The key to growing blueberries is having a cool winter for the plants to go dormant, he said. Gainesville and North Central Florida are ideal for that, he said, but further south where the winters are milder isn't ideal for blueberries.

"There is a big move to grow blueberries as an evergreen plant," Olmstead said. "That is the one thing we are trying to select for."

The earlier they can get the berries to grow, the better. Grocery stores in the U.S. receive the last shipments of late harvest blueberries from the southern hemisphere in late February. Florida blueberries are ready for harvest in March and April.

"We're the only players in the game," Olmstead said.

Last year, UF released an evergreen cultivar called the Arcadia, which seems to meet much of the desired criteria - sweet and not too tart, and a high yield. And it's showing phenomenal yields in south Central Florida.

"We get everything put together," Olmstead said. "Every new release is trying to move toward that ideal blueberry."

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