How to beet artificial food colouring

Cornell University food scientists have found beet extract paired with a starchy partner can create a stable, natural red food colouring to replace artificial dyes.

“Many processed foods in the United States — like fruit jams, candy, snacks and beverages — contain red dyes,” said senior author Alireza Abbaspourrad, the Yongkeun Joh Assistant Professor of Food Chemistry and Ingredient Technology. “Through other scientific studies, some artificial dyes are implicated in health problems, such as attention deficits and allergies in children.”

Instead, the food scientists looked to improve the effectiveness of many naturally available dyes, such as the red betalain pigments found in beet extracts. On their own, these natural pigments can discolour after only a few days, and keeping them shelf-stable has been an industry problem.

Published in the journal Food Hydrocolloids, their research found that the natural red colour improves in stability after beet extract is attached to a substrate of negatively charged polysaccharide (a long chain of sugar molecules), such as xanthan gum or alginate. These are natural food ingredients based on plant extracts and are used as thickeners in the food industry.

Co-lead authors Meghan Marchuk and Michael J Selig, from the Department of Food Science, worked with Detlef M Smilgies, a staff scientist at the Cornell High Energy Synchrotron Source (CHESS), to use Cornell’s Quartz Crystal Microbalance with Dissipation (QCM-D) instrument to assess the beet extract’s adhesion to the alginate, xanthan gum or other potential substrates.

When attempting to wash the red colour out from potential substrates, they found that the beet extract remained attached to the alginate and xanthan gum’s chemical chains like what they described as “chemical velcro”.

The QCM-D results indicated that these substrates bound the pigment better than substrates such as gum arabic and beet pectin, which retained less beet extract and allowed the red dye molecules to rinse away when washed.

Abbaspourrad said this research introduces a new way to enhance the stability of natural food colours. “This may lead to a replacement of artificial food colors with their natural counterparts on a large scale in the food industry,” he said.

The research was supported by the Department of Food Science in the College of Agriculture and Life Sciences. CHESS is supported by the National Science Foundation.

Image credit: ©stock.adobe.com/au/iMarzi

Originally published here.