A special type of purple corn may soon help replace artificial food dyes in many foods and drinks, according to new research from the University of Missouri.
Scientists say this colorful corn not only provides a natural source of bright pigments but also offers health benefits and remains stable during food processing, making it a promising alternative for the food industry.
The study, published in the journal npj Science of Food, focuses on a variety of purple corn that has been grown in South America for generations. Its rich purple color comes from natural plant compounds called anthocyanins.
These are the same pigments that give blueberries, grapes, blackberries, and red cabbage their deep red, blue, and purple colors.
Unlike artificial food dyes, which are made from petroleum and are used only to improve the appearance of food, anthocyanins are also antioxidants.
Antioxidants help protect the body’s cells from damage and have been linked to reduced inflammation and better heart health. This means purple corn could offer both attractive color and added nutritional value.
The researchers found that most of the valuable pigments are located in the corn’s outer layer, called the pericarp.
This is the thin coating that surrounds each kernel and is sometimes the part that sticks in your teeth when you eat corn. While it may seem unimportant, it is actually packed with the natural compounds scientists want to use as food coloring.
One of the biggest challenges in replacing artificial food dyes has been that many natural colors are not very stable. Heat, light, oxygen, and long storage times can cause plant-based colors to fade or break down. Food manufacturers need ingredients that can survive cooking, processing, packaging, and weeks or even months on store shelves.
To test whether purple corn could meet these demands, the University of Missouri team exposed its natural pigments to high temperatures similar to those used in food production. After heating the pigments for one hour, about 75% of the important color compounds were still present. This level of stability is encouraging because manufacturers mainly care about whether the finished product keeps its color after processing.
The researchers achieved even better results by coating the pigments with food-safe protective materials. This method preserved nearly 97% of some of the color compounds during heating. It also allowed the pigments to be turned into shelf-stable powders that are easier to package, transport, and store for commercial use.
The team also tested the purple corn pigments in beverages, which are especially difficult for natural colors. Drinks are often acidic, exposed to light, and stored for long periods, all of which can damage natural ingredients. Even under these challenging conditions, the purple corn colorants performed well. After seven weeks of refrigerated storage, the drinks showed very little color loss, suggesting the pigments could work well in fruit juices, sports drinks, flavored waters, and other beverages.
The researchers believe this combination of durability and potential health benefits could make purple corn an attractive choice for food companies looking to replace artificial dyes with natural ingredients. As more consumers seek products with simpler ingredient lists and fewer synthetic additives, natural colorants like these may become increasingly valuable.
The project could also create new opportunities for American farmers. Missouri is already one of the nation’s largest producers of yellow corn, but purple corn is not well suited to the region’s climate.
Over the past five years, researchers have been crossbreeding colorful purple corn with corn varieties that grow well in the Midwest. Their goal is to produce hybrid plants that maintain their vibrant color while also delivering strong crop yields.
If successful, farmers across the Corn Belt may one day grow purple corn alongside traditional varieties, supplying the food industry with a stable, natural source of color while opening up a new market for agricultural producers.
The researchers believe this colorful crop could play an important role in creating healthier and more natural foods in the years ahead.
