Flavor first: Engineering sweeter strawberries

Dr. Chieri Kubota's grad student, Katie Fulcher, examines strawberries growing in the production greenhouse at the Controlled Environment Agriculture Research Complex on Waterman Lab.

In the Controlled Environment Agriculture Research Complex (CEARC), researchers are partnering with agricultural industry leaders on projects due to the growing demand for better-tasting strawberries and the increased growing capabilities of greenhouses. The three current strawberry research projects are unlike any other in the United States, as they connect research and science with market and economic drivers.

Chieri Kubota, a professor in the CFAES Department of Horticulture and Crop Science, and director of the Ohio Controlled Environment Agriculture Center at Ohio State, is leading the research with a goal for Ohio to become a key player in the country’s strawberry production.

Kubota in the CEARC, another research project on tomatoes can be seen in the production greenhouse behind her.

If growing conditions can be perfected in Ohio, the market could potentially provide off-season, flavorful fruits throughout the Midwest and East Coast.

“In the United States, strawberries are just ornamental, adding color to your table, and that’s it. Not the flavor, not the joy,” Kubota said.

Ohio’s ripe for growing strawberries

One of the strawberry research projects is funded by the Ohio Controlled Environment Agriculture Center (OHCEAC) Consortium, a partnership between academic and industry leaders that focuses on controlled environment agriculture and collaborative research. Currently in its second year, the goal of the project is to produce strawberries in Ohio that compete with strawberries grown in California, utilizing a greenhouse environment.

Nearly all of U.S. strawberry production and propagation is in open fields using soil. Kubota explains that the technology for strawberry greenhouse production or indoor vertical farms has yet to be perfected, which is why these projects are so important.

“We are growing plants in a very clean environment,” Kubota said. “This includes an irrigation system infused with nutrients and fertilizers.”

No soil means the researchers have less pests and diseases to combat, so no pesticides are used on the strawberries.

Fulcher uses a digital caliper to measure strawberries as they grow in the production greenhouse.

“We know the exact amount of water fertilizers applied to the strawberries, so that is a very efficient production system with minimal waste,” Kubota said.

Kubota said Ohio State’s temperature and humidity-controlled greenhouse, located at CFAES’ Waterman Agricultural and Natural Resources Laboratory, is similar to the California coastal environment. She adds that Ohio’s environment in the winter is perfect for the temperature-controlled environment that strawberries thrive in.

“The greenhouse has a nice temperature of between 50 and 55 degrees, cool and humid at night, which is like the fog coming from the ocean. That is very important for the strawberry,” Kubota said.

Expanding the flavors of strawberries

Healthy foods should have exciting flavors, said Devin Peterson, director of the Ohio State Flavor Research and Education Center and Distinguished Professor in the CFAES Department of Food Science and Technology. An award-winning flavor scientist, Peterson is leading research on how to expand the flavors of strawberries while keeping the nutrition and durability intact.

Dr. Devin Peterson leads the Foods for Health Leadership Team at The Ohio State University to promote health through scientific discovery in food and nutrition.

“We eat for pleasure. I want to eat healthy foods that are healthy and satisfying. You can do both if you understand the science,” Peterson said.

Peterson partnered with Kubota and received research funding from the Foundation for Food & Agriculture Research. In the second year of the four-year project, the research focuses on understanding the flavors, textures, and scents of strawberries that would arouse consumers.

“In commercial production, strawberries are selected for several reasons. One important one is always yield and profitability. A lot of times they’re not selecting for flavor,” Peterson said. “This project is stepping away from that and asking, ‘If we understood better what is driving premium flavor with the wide range of molecules that exist in strawberries in nature, how can we use that information?’”

Using vertical farming technology in a controlled growing environment, Peterson’s research includes consumer sensory testing to understand what strawberry attributes are most appealing. Peterson said sugars, acids, and how the tongue perceives those flavors and textures can be enhanced on a molecular level based on consumer feedback.

“We want to know what needs to happen in the growing environment to help optimize that formulation that creates a berry that people want to buy,” Peterson said. “If you think about strawberries, this is such a good example of why flavor matters. You can buy strawberries in the middle of winter, and most people think they taste like wood, even if the nutrition is excellent.”

A row of strawberries grow in the short stature crop production greenhouse. Flags mark each experimental block and plants used for measuring crop growth.

Research that drives industry impact

Strawberries are one of the most in-demand fruits in the United States in the winter, said Octavio Rodriguez, director of growing operations for Nature Fresh Farms’ Delta, Ohio, facility. Nature Fresh’s 45-acre organic strawberry farm is a part of Ohio State’s strawberry research projects.

“We are learning new techniques and strategies, and getting to know new varieties that are in the market that are suitable for this area,” Rodriguez said.

As a member of the OHCEAC Consortium, Rodriguez meets with Ohio State researchers at least monthly to discuss strawberry research findings, benchmarking them against the industry knowledge at Nature Fresh.

Ohio’s strawberry future

A third project on strawberry propagation will use the outcomes of both the greenhouse and flavor research to optimize strawberry planting. Kubota said the results of this research may take several years to complete.

“With strawberries, you have to start with planting materials. You can’t start from seeds,” Kubota said. “You have to have plants that are propagated using runners that can be cut into individual small plants and then rooted. The technology suitable for greenhouse or indoor vertical farming doesn’t exist in this country and is relegated to the background. It is very important, and that is why we are doing this.”

As strawberry propagation is typically done with soil, Ohio State researchers are developing hydroponic and lighting technologies to create cleaner propagation.

“We want to understand how we can propagate efficiently using a greenhouse, by manipulating temperature, light, and conditioning,” Kubota said.

The strawberry research currently includes undergraduate, graduate, doctoral, and postdoctoral students, as well as staff from both the college and the Flavor Research and Education Center. Peterson said the collection of projects aligns with Ohio State’s land-grant mandate.

“We have a mission to elevate food and agriculture to have more impact on health and wellness. This is an example of how we look at the food supply and elevate it to have healthier choices that are maybe more valued,” Peterson said.

Kubota said that the research being conducted today could change the U.S. strawberry market within the next decade.

“Maybe in five years from now, consumers might start seeing greenhouse-grown strawberries from Ohio in the wintertime because of our efforts,” Kubota said.