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Breeding for pest and disease resistance in plants is common practice in modern agriculture. Scientists typically focus on breeding for traits that result in higher yields and a longer shelf-life to keep up with supply and demand. But in this Bonus Bite episode, we shift into a conversation about breeding for flavor, a mostly neglected trait up until now. Flavor breeding is considered “the last frontier of plant breeding” by some experts and could bring tastier products to our tables. This episode covers the work of UC Davis researchers in search of a tastier fruit.

In this episode:

Steve Knapp, director of the Strawberry Breeding Program. His research focuses on the breeding, genetics and genomics of strawberries.

Florence Zakharov, flavor expert and associate professor of plant sciences. Her research focuses on the development of fruit aroma and the chemical elements and objective assessment of fruit flavor.

ALEXA: When I turned a year old, my parents threw me a big birthday party at Chuck-E-Cheese. They invited lots of people and ordered pizza, obviously, cake.

AMY: Hey, did you know that Chuck-E-Cheese was co-founded by the guy who created the Atari gaming system, like Pong?

ALEXA: I did not. But that actually makes a lot of sense since Chuck-E-Cheese is an animatronic. But anyways, we're getting off topic- all I wanted to do that day was eat strawberries. In photos from that day, I’m covered in strawberries. And a few years later, I requested a strawberry pinata for another birthday party. I’ve always been super obsessed with strawberries. It’s almost like your obsession with carrots, Amy.

AMY: Baby-cut carrots. There's a difference.

ALEXA: Anyways, most of the thousands of strawberries I’ve eaten throughout my life probably came from UC Davis. Our strawberry breeding program has been researching and innovating my favorite fruit for nearly 70 years now.

AMY: And the U.S. is the world’s largest producer of strawberries. Almost 90 percent of those strawberries are grown here in California and 60 percent of the state’s strawberries are varieties developed here at UC Davis. And these are just facts that I happened to have memorized.

ALEXA: Of course you do! Not only is UC Davis continuing to create better strawberries, like the five varieties released over the summer, but the university is also now working on flavor breeding.

AMY: Flavor Breeding. Hmm, bet it’s time for a Bonus Bite?

ALEXA: You know it. I’m Alexa Renee.

AMY: And I’m Amy Quinton.

ALEXA: And in this episode, we’re going to talk about flavor breeding and what that could mean for my favorite fruit.

AMY: Ok Alexa, let’s start with the basics. What is flavor breeding?

ALEXA: It’s exactly what it sounds like. Plant breeders take a crop, in this case the strawberry, and identify the traits that make it taste good. They’ll cross the plant through generations, over and over again, each time emphasizing the characteristics they want to stand out. Eventually, the result is a more delicious fruit.

AMY: So it’s really similar or the same to breeding for pest and disease resistance or for longer shelf-life or higher yields.

ALEXA: Yes. But the problem is, because scientists have been so focused on breeding for the traits you just named off, along the way flavor was kind of neglected. And Steve Knapp- the director of the UC Davis Strawberry Breeding Program- realized this.

STEVE: I'm asked about flavor almost everywhere I go. It was one of the striking things when I was trying to just absorb what had been done and what we need to do in the future and whether it was a consumer at home, growers, shippers, colleagues, everybody would ask me what happened to strawberry flavor?

AMY: Steve explains that really, nothing has happened to strawberry flavor.

ALEXA: Those strawberries you grow in your home garden or those that you might find from a small producer, they’re packed with flavor.

AMY: But not those you find in the grocery store that dominate the marketplace.

ALEXA: That’s because commercial strawberries are mainly bred to produce high yields with a longer shelf-life.

STEVE: It's a tricky process because you can't get something for nothing, right? The reason they store and ship is that they’re extremely firm, and they don’t ripen the same as the home garden strawberry.

ALEXA: So Steve is hoping to find the sweet spot. He’s put together a team of experts across disciplines to collaborate on achieving a strawberry that’s both delicious and marketable.

AMY: The team includes geneticists, sensory scientists, post-harvest researchers and growers.

ALEXA: And consumers?

STEVE: That is the really underlying driver behind the flavor initiative is that, we can already mass produce the fruit well- all that system in place. The consumer and retail side is increasing in their sophistication and demands. And so we’re going to try to find some balance between the mass production traits- you know the high yield and flavor. And that's really the crux of the project.

ALEXA: To give consumers what they want, scientists have to take a close look at flavor itself. Which is where Florence Zakharov can be very helpful. She’s a flavor expert in the Department of Plant Sciences. Her team focuses on melons but their overall work in
understanding the flavor trait on a molecular level is important to flavor breeders of any crop.

FLORENCE: Flavor is a really complicated trait in plants.

AMY: Because it involves so many different aspects like texture, color, taste and aroma.

FLORENCE: We're studying how flavor gets produced in plants with a special emphasis on volatile compounds. These are very small molecules that are present say, in your perfumes or any smell that you experience is made up of these small molecules called volatile compounds. And they can be made by plants. And we study how plants make these things so we look at genes that are involved in the process of making these compounds, when they make them and perhaps why they make them.

ALEXA: Machines measure these volatile compounds. But because taste can be so subjective, researchers also turn to sensory experts or consumer focus groups.

FLORENCE: This cross-referencing of the instrument measurement and the sensory human perception of flavor- those two things come together in this relatively new science called chemometrics. Chemometrics looks at objective ways of measuring flavor. How can we relate those objective flavor measurements to a rather subjective perception of flavor from a human standpoint?

AMY: Ok, so we know what flavor breeding is and how it’s done.

ALEXA: Yeah.

AMY: We know how flavor components are identified.

ALEXA: Mmm hmm.

AMY: And we know how flavor is measured.


AMY: And we know we’re working on flavor breeding with the strawberry. So when are we going to see these better tasting berries in stores?

ALEXA: Well, the challenges of this project go beyond plant breeding. Steve says it’s difficult to produce more flavorful strawberries because most commercial nurseries are set up to grow strawberry varieties for the industry where the demand is huge.

STEVE: The specific problem that we've been challenged with is finding a nursery grower that can deal with small volumes.

AMY: Steve said most strawberry nurseries in the state simply don’t have their equipment set up for small production. 

STEVE: We just need somebody that is working on a smaller scale that wants to farm on a smaller scale that has greenhouse facilities and land and wants to jump into this. So we're looking right now. We're trying to find partners and we're talking to folks that work in a more local agricultural way. And hopefully we'll find somebody that is innovative on nursery site to help drive that.

ALEXA: And even them on a smaller, local level will take the right economic incentive.

STEVE: It's really a matter of pairing the producers with the direct consumers- whether the restaurants or Farmers Markets- and those folks often need to have a premium for their product because they're not mass produced. To me it's partly an economic question. You know, who can afford that more expensive fruit? It's just a question of their input costs and pricing.

ALEXA: Breeding for flavor is still a relatively new concept. Florence called it the "last frontier" in plant breeding.

AMY: Yeah, there are other plant breeders across the country working on developing better tasting crops.

ALEXA: But the “seed-to-fork” movement is still in its beginning stages. Products are still limited to specialty restaurants or small tastings.

AMY: But hopefully with UC Davis’ help, a more flavorful strawberry will find its way to consumers soon.

ALEXA: Thanks for listening.