The project, which is in its beginning stages, was sparked by a Center for Innovation in Teaching and Research (CITR) initiative to match University faculty in a mentoring relationship. The program paired WIU Assistant Professor of Chemistry Mette Soendergaard with Assistant Professor of Agriculture Shelby Henning, who came to the University in Fall 2017.
"After we began talking about our research, we found we had common research interests—we had both done research involving vegetables before," said Soendergaard.
The common interest sparked the idea to study tomatoes and the antioxidants they contain in terms of cancer prevention, and to look further into whether heirloom tomatoes have different disease prevention qualities than more commonly encountered, commercially grown varieties. Henning planted and grew the seven types of tomatoes in Western's new greenhouse facilities on the north end of campus, and Soendergaard and her students took the harvested products to the laboratory for testing.
Henning grew the tomatoes hydroponically, in volcanic rock, instead of soil. He added a trellis system to a portion of one of the new School of Agriculture greenhouses in December 2017 and began the plantings.
"The heirloom tomatoes have health benefits, and we are looking at plant pigments; the more highly pigmented they are, the more antioxidants they tend to have," said Henning. "We are looking at the antioxidant connection to cancer prevention."
Part of the research involves grafting heirloom varieties to several different rootstocks in an effort to improve plant health and yield. The plantings start at about eight inches tall and can grow into vines of up to 30 feet. The varieties are characterized as "indeterminate," which Henning said means they grow and continue to produce tomatoes as long as "the weather is conducive."
"I used to have a two-year-old indeterminate tomato I grew for demonstration purposes," he said. "They never stop growing and can produce four to five pounds of tomatoes per plant per month. Many commercial growers plant hydroponic crops during the winter months, so they can market locally-grown and fresh product at a time when traditional field producers cannot. Those who get to the market earliest can set the prices."
In the new WIU greenhouse facility, the tomato plants are automatically fed fertilizer solution for one minute each half-hour. The plantings include a "green zebra" variety that doesn't turn red when ripe, which Henning said was thrown in to test pigment theories. Henning checks on the plants at least once each day.
In the laboratory
Beginning in March, the tomatoes were harvested from the greenhouse and were turned over to Soendergaard and her students. The laboratory testing portion of the study is headed by WIU chemistry graduate student Jamie Greathouse, of Macomb, and involves students Rebecca Kielminski, a senior pre-pharmacy major from Villa Park, IL; Sean Pollock, a senior pre-pharmacy major from Peoria, IL; and Mallory Burg, a junior pre-med major from Macomb.
The students cut the tomatoes into slices, freeze dry them and grind the result into a powder. The powder extractions are then tested with various solvents, a process which is just beginning.
"We are interested in the antioxidants in terms of cancer prevention and whether heirloom tomatoes are different than those that are commercially grown," said Soendergaard. "We are trying to see whether we can grow the heirloom tomatoes efficiently and how it impacts the health benefits."
Soendergaard said the heirloom varieties were chosen because they have not been bred or crossbred to be commercialized for taste and color.
"These aren't pretty tomatoes," she said. "But we hope to see if grafting to rootstocks produces maintainable health benefits."
Greathouse signed on to lead the student research as part of her master's thesis.
"I was talking to Mette about upcoming research and I was interested in this project because I have a background in nutrition," she said. "This whole process also helps me start to trust myself more in the lab."
Pollock is working in the laboratory as part of his undergraduate research requirement. He has been freeze-drying the tomato slices and said the practical experience he has gained has helped him with laboratory procedures, which will be valuable with his future career goals in nutrition.
"I have been doing things like changing the oil in the vacuum and prepping the tomatoes," he said. "I have learned it's the little jobs that add up. I know what it's like to be one small cog in a big research project."
For Kielminski, the experience has given her the research skills she needs for classroom requirements, and for her pharmacy career goals.
"We have more freedom to figure out the best way of doing things," she said of her laboratory time. "It's a good stepping stone."
Burg said the laboratory experience she has gained this semester has made her a more well-rounded student.
"I can apply what I've learned in the classroom and in the lab to real-world problems, such as preventing cancer and heart disease," she said.
While the project is in its exploratory phase, Henning and Soendergaard have applied for an Illinois Department of Agriculture Specialty Crop grant to expand the scale of the project. The grant will hopefully be awarded this fall.
"We would like to look at more combinations of grafting rootstocks," said Henning. "There are hundreds more highly pigmented tomatoes. We hope to identify novel pigments and look at them for anti-cancer compounds."
It is expected that the research project could last several years and include additional students in the processes.
In terms of the CITR program, which provides professional development opportunities for the WIU community, the mentoring program is just one aspect of faculty support.