Researchers at the University of Missouri’s College of Agriculture, Food, and Natural Resources are turning a unique variety of purple corn into a natural alternative to artificial food dyes. This corn, traditionally grown in South America, gets its color from anthocyanins, natural pigments that are also found in blueberries, red cabbage, and grapes.
These pigments are not only responsible for the corn’s color, but they’re also rich in antioxidants that can help reduce inflammation and support heart health. Unlike artificial dyes, which are petroleum-based and added solely for appearance, anthocyanins have potential health benefits.
For food manufacturers, replacing synthetic dyes like Red No. 40 and Red No. 3 has been a challenge. Most natural colors are fragile and tend to break down when exposed to heat, light, or oxygen, making them difficult to use in food processing.
Pavel Somavat, a researcher with joint appointments in Mizzou’s College of Agriculture, Food, and Natural Resources and the College of Engineering, notes that most natural colors are fragile. They tend to break down when exposed to heat, light, or oxygen.
This has become a major barrier in the food industry, where ingredients must withstand processing temperatures up to 250 degrees Fahrenheit and remain stable on store shelves for weeks or even months. The team is working to overcome this barrier.
Researchers at Mizzou are tackling this problem by testing the durability of purple corn colorants. In one test, they exposed the colorants to high temperatures often used in food processing and found that about 75% of the key color compounds remained intact after one hour.
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When the team coated the pigments in protective, food-grade materials, retention increased to nearly 97% for some compounds. This process allows researchers to create shelf-stable powders, making purple corn-based colorants easier to store and transport.
The team also tested their purple colorants in a beverage system, one of the most demanding environments for natural dyes. The results showed that purple corn-based colorants held up well in acidic and basic environments, making them a strong candidate for natural food dye alternatives in fruit juices, flavored waters, and sports drinks.
Missouri is one of the nation’s leading producers of standard yellow corn. For the past five years, Mizzou researchers have been working to adapt purple corn to growing conditions in the Corn Belt in hopes of expanding production and diversifying revenue streams for farmers.
In collaboration with Sherry Flint-Garcia, a research geneticist with the US Department of Agriculture’s Agricultural Research Service, the team is developing hybrid varieties that balance intense color with strong performance. The goal is to create a type of purple corn that can be grown successfully in places like Missouri, allowing farmers to benefit from its healthy properties.
The study’s findings demonstrate the potential of purple corn as a natural replacement for artificial food dyes. With its durability and potential health benefits, purple corn colorants could become a viable option for food companies looking to create cleaner labels without sacrificing performance.