Corn Flour Color Schemes
by Laurie Gorton
Mother Nature painted corn with more colors than just yellow and white. Its red, blue and purple pigments can improve bakery and snack formulations with natural antioxidants plus bright colors.
The blue, crimson and purple of specific corn varieties contain the flavonoids classified as anthocyanins. Odorless and nearly flavorless in their native state, these water-soluble antioxidants are now available thr-ough highly pigmented corn flours.
SK Food International, Fargo, ND, offers red, blue and white cornmeal and corn flour, said Tara Froemming, who works in business development with the company. Red is the newest. “With our Crimson Red Corn, the color is in the grain’s aleurone layer, so it is maintained throughout processing,” she explained. Thus, red-colored extruded snacks and corn tortillas made with it can list corn as the single ingredient — no color additives needed.
The identity-preserved, US-sourced hybrid corn variety used for Crimson Red Corn products has hard starch characteristics that promote uniform milling vs. soft starches that crumble when milled. The milling process removes its clear seed coat, and the hybrid has a gametophyte gene that prevents cross-contamination with other types of corn, including genetically modified (GM) varieties. The corn is certified-organic and kosher, as well as whole-grain and gluten-free.
Suntava, Afton, MN, supplies US-grown, non-GM Purple Corn ingredients made from a proprietary hybrid produced by traditional breeding. “Suntava’s purple corn owes its bright, vivid color to its extremely high level of anthocyanins,” said Terry Howell, director of business development, Suntava. Brunswick Laboratories, an independent contract lab based at Southborough, MA, tested the corn and confirmed an oxygen radical absorbance capacity (ORAC) value ranging from 5,000 to 7,000 per 100 g. ORAC measures antioxidant capacity.
Many tortilla and snack producers use blue corn in their products, but Mr. Howell said that purple corn contains nearly four times the anthocyanins found in blue corn, according to a 2006 study published in the Journal of Agriculture and Food Chemistry
This antioxidant activity survives processing quite well, according to research reported at this year’s AACC International annual meeting by Mary Ellen Camire, PhD, professor, food science and human nutrition, University of Maine, Orono, ME. She and her colleagues put blue cornmeal through a twin-screw extrusion process typical of puffed snacks and breakfast cereals. Antioxidants survived best under cooking conditions of 150°C (302°F) with 21% formula moisture and at 165°C (329°F) with 24% moisture. The group plans to continue its studies to help retain these phytochemicals for both their color and health benefits.
The pH of the formula also plays an important role. Mr. Howell recommended a pH range of 2 to 5 to maintain purple color. By changing the pH, formulators can create naturally colored finished products ranging in hue from pink to red to purple.
“Whether used as a stand-alone food ingredient in products such as tortilla chips or as an inclusion in multigrain cereals, snacks or baked goods, Suntava Purple Corn delivers the whole-grain goodness, natural flavor, rich natural color and value-added nutritional punch today’s health-conscious consumers seek,” Mr. Howell said.