Ohio State researcher, Monica Giusti, proposes natural replacements for synthetic dyes like Red Dye No. 3.
Credit: Faith Schneider | Lantern Photographer
The U.S. Food and Drug Administration banned Red Dye No. 3 Jan. 15, and food manufacturers are scrambling for safer alternatives.
Ohio State researcher Monica Giusti has spent years studying natural colorants that could potentially replace synthetic dyes while offering additional health benefits.
Red Dye No. 3 is a synthetic food dye found in certain foods and beverages that have a “bright, cherry-red color,” according to the FDA website. This dye has been shown to cause cancer in male laboratory rats that were exposed to high levels of the colorant, violating the Delaney Clause of the Federal Food, Drug, and Cosmetic Act.
Giusti, a distinguished professor and associate department chair in the Department of Food Science and Technology, leads groundbreaking research on anthocyanins — natural pigments found in fruits and vegetables like blackberries, red cabbage and grapes, according to the National Institutes of Health.
She said her work focuses on making these pigments more stable and commercially viable, which helps food companies adopt natural colorants that meet consumer demand for clean-label ingredients.
“By replacing synthetic colors with natural ones, we’ll be introducing more antioxidants into our diets, and society will benefit from the wonderful compounds that come from fruits and vegetables,” Giusti said. “Hopefully, health will improve as a result.”
As food companies navigate the shift away from synthetic dyes, Giusti’s work is bridging the gap between science and industry.
Adri Wilburn, a licensing analyst in the Office of Innovation and Economic Development, has worked with Giusti — and other researchers like her — to initiate strong business relationships.
“Within OSU Innovation and Commercialization, my role in the process is to initiate and foster conversations between inventors like Dr. Giusti, businesses that are potential commercial partners, and my office,” Wilburn said in an email. “These early conversations are crucial to ensure the partnership and technology are a good fit for all parties involved.”
Giusti said the push for natural colorants has been ongoing for over a decade, but the FDA’s ban on Red Dye No. 3 has recently spurred many companies into action.
“We’ve received a lot of emails and contacts from companies looking for help with color solutions,” Giusti said.
Giusti said switching over to natural colorants often requires re-evaluating entire manufacturing processes.
“If you replace a synthetic color with a natural one, it might be better to add the colorant at a later stage in production,” Giusti said. “This means companies need to rethink their processes, which is a significant challenge.”
The biggest challenges with implementing natural dyes are stability and color consistency, Giusti said. Even if a natural dye closely matches the original synthetic shade, it may appear slightly different in the final product. This variation can be a problem for brands with well-known products.
“If your favorite drink is a little more purple or a little less orange, consumers may wonder, ‘What’s wrong with this?’” Giusti said.
Giusti’s research has generated over 120 peer-reviewed publications and eight patents, with additional patents pending, according to the Giusti Phytochemicals Lab website.
“We have set up a lab that is focused on the study of phytochemicals,” Giusti said. “Anthocyanins are the ones that give those orange, red, pink, purple, blue colors, even some black colors in many fruits and vegetables,”
Notably, the Giusti Lab is made up of graduate and undergraduate students, each working on a different aspect of polyphenol research.
“Each student has their own project,” Giusti said. “One may be looking into a new plant material as a potential source of colors, another may be comparing stability to see which color works best in a particular food application and another may be studying strategies to make the colors last longer in storage.”
Giusti said a key focus of the lab is improving the stability of natural colorants, as plant-based pigments can degrade when exposed to heat, light or acidic environments.
“Currently, we have several projects related to making food colorants that are derived from nature but that are more stable,” Giusti said.
Giusti’s lab has been able to collaborate with food manufacturers to offer customized solutions for their specific needs, such as in products like fruit juices, sports drinks, candies and baked goods, Giusti said.
“For example, maybe one of [Guisti’s] colors is very stable in acidic conditions, but the company we reach out to is actually trying to find a solution for color stability at higher temperatures,” Wilburn said. “It is exciting though when these disconnects become collaborative opportunities where faculty like Monica will work with the company to develop a solution to their particular problem.”
Giusti’s lab has also expanded to study cosmetics, including projects on lipstick. She highlighted the distinct challenges of ensuring stability in makeup products, which are often subjected to extreme temperature fluctuations upon purchase.
“It’s very common for people to leave lipstick in their car, and it could be exposed to 110 degrees Fahrenheit one day and minus 20 the next,” Giusti said. “We look at stability under these extreme conditions because these factors play a big role in how the color holds up and how the product performs.”
Giusti said she studied food engineering in Peru — her home country — before moving to the United States for graduate school. She earned both her master’s and Ph.D. in food science from Oregon State University.
Giusti said food is more than just sustenance — it’s about enjoyment, memories and social connection.
“In food sciences, of course we care about the nutritional value of foods, but we also care a lot about the experience of eating,” Giusti said.
This perspective led Giusti to explore the various roles of food pigments, which not only make foods visually appealing, but can also provide health benefits.
Giusti said as a student, she worked on a project examining how red radish pigments can be used as a natural dye for maraschino cherries. This experience sparked her interest in plant-based colorants, laying the foundation for her future work in developing natural alternatives to synthetic dyes.
Giusti ultimately believes her research on natural colorants offers more than just a visual benefit.
“My compounds can provide the visual benefit and the antioxidant capacity, the anti-inflammatory capacity, the lower risk for chronic diseases,” Giusti said.
Giusti said despite decades of advice encouraging people to eat more fruits and vegetables, the increase in their overall consumption has been minimal.
“One way of improving the diet is by introducing more compounds from fruits and vegetables into a wider range of foods,” Giusti said.
This approach could help integrate healthier, plant-based compounds into everyday diets, making them more accessible without requiring consumers to drastically change their eating habits.
Giusti specifically pointed to California’s ban on synthetic colorants in schools as a catalyst for wider change.
California Gov. Gavin Newsom signed the bill, formally titled “California School Food Safety Act,” Sept. 28, 2024. It prohibits schools from serving foods, drinks and snacks that contain six artificial dyes and will go into effect Dec. 31, 2027, according to NBC News.
That’s causing a chain reaction,” Giusti said. “If companies have to change their formulations for schools in California, they may also be preparing to make similar changes at the national level.”
Overall, Giusti said she feels optimistic about the long-term health benefits of replacing synthetic dyes with natural alternatives.
“I’m a big believer in the potential health benefits of these compounds,” Giusti said.
