The Need

Food coloring is an important factor of the consumer's perception of the quality and flavor of a food product, boosting the product's overall success. Not only does it provide a different color to food products, it even helps prevent color loss during long-term storage. However, in recent years, the demand for natural food coloring is growing because consumers are concerned about synthetic dyes and the impact on their health. The natural food colors market is expected to be worth $3.2 billion by 2027. and there is ongoing reseach in the industry for brilliant food dyes that are natural with a focus on colors such as cyan blue. Developing a blue nature colorant is somewhat difficult given the rarity of this color in nature but resechers at OSU have developed an editable vibrant and stable anthocyanin-based blue colorant for use in acidic environments.

The Technology

Researchers at the Ohio State University, led by Dr. Monica Giusti, have developed an editable vibrant and stable anthocyanin-based blue colorant for use in acidic environments. The statrting materials needed to form this anthocyanin complex were isolated from American eggplant peel and Yerba Mate. Blue complexes were formed by mixing different ratios of eggplant extract and Yerba Mate extract. Complexes were successfully produced at pH 4, and the blue hue remained even when the pH was decreased to 2.90. The λmax (586-580 nm) and hue angle (264–266°) did not significantly change when the pH decreased from 4.09 to 3.33. At pH 3.10-2.90, the hue turned to purplish blue (h = 273° to 284°). At lower pH the blue color was lost. The colors remained remarkably stable over 2-month storage at 4℃, with no significant change in the λmax and > 75% blue color retention.

Benefits/Advantages

This work performed by the Giusti lab has produced a new potential blue colorant for the food industry using readily available edible materials to create a natural Blue-Complex colorant. The blue complex was formed by using eggplant extract and Yerba Mate and express blue color at pH as low as 2.90 for 2 months refrigerated storage, providing a new natural blue food colorant for the food industry.