Blue and purple corn may not spring to mind as a ‘must buy’ food but there seems to be a market for it. Having differently colored tortilla chips has been around for a while, but there seems to be a driver for corn itself. Creating a naturally based dye, however, is more problematic. This difficulty has been overcome by chemists from the University of Illinois.
Explaining how naturally produced dyes are made and where they come from, food dye researcher Dr. Jack Juvik states: “Most natural colors come from things like wine skins, red carrots, and beets.”
He goes on to explaining the difficulties when extracting dyes: “The problem with that is most of the product is wasted in extracting the coloring. It’s not good value.”
As part of experiments for creating purple and blue corn varieties, Dr Juvik has noted pigments known as anthocyanins are located in the outer layers of the corn kernel. Some researchers see health benefits associated with anthocyanins. These are water-soluble vacuolar pigments that may appear red, purple, or blue depending on the pH. Anthocyanins are members of the flavonoid group of phytochemicals, a group predominant in teas, honey, wines, fruits, vegetables, nuts, olive oil, cocoa, and cereals. With regard to health, it could be that anthocyanins possess anti-inflammatory and anti-carcinogenic activity. This may further extend to cardiovascular disease prevention, obesity control, and diabetes alleviation properties.
Due to the potential health promoting properties, Dr Juvik regards the outer layer of corn as a “value-added co-product.” So far his research institute have spent $1.4 million identifying the optimal milling process designed to recover stable corn rich anthocyanins. These chemicals can then be used as sources of the pigments for future corn breeding.
As part of a major review, Dr. Juvik has studied anthocyanin types across 400 genetically different lines of corn. The aim of this was to determine whether anthocyanin concentrations remained constant from generation to generation — a critical quality for breeding new varieties.
Peruvian types had some of the highest anthocyanin concentrations, and they held up throughout multiple generations. “That’s good news. It means we can select for the trait we’re interested in without worrying whether it will be expressed in new environments,” Juvik says.
The next step will be getting those mighty Peruvian genes into high-yielding corn hybrids selected for production in the Midwest. If Juvik is successful, blue or purple corn could come to a field near you.
The research has been published in the Journal of Agricultural and Food Chemistry. The research paper is titled “A Survey of Anthocyanin Composition and Concentration in Diverse Maize Germplasm.”
