Scientists Develop Non-Toxic, Food Safe Paint

An edible, non-toxic, environmentally friendly, removable paint has been created by scientists at Cornell University to be used in candy and dietary supplements.

This edible paint made by creating colored calcium alginate hydrogels is a new form of colored coating that has a wide range of applications, including food and dietary supplements.

Lead researcher D. Tyler McQuade said that, although the technology was originally developed for non-food use, the food industry could benefit.

He said, ‘I think that our advance is solely in the area of coatings. This could be used for coating candy or dietary supplements. If sugar were added to the coating it could be a candy itself.’

The researchers tested their technology by focusing on coating artificial turf. They did this by spraying an aqueous solution of calcium chloride (gelling agent), followed by spraying sodium alginate with one per cent red food color (McCormick). The sprayed solutions then combined into a colored thin film.

Although the researchers used the red food color for these preliminary experiments, there could by a potentially extensive range of dyes that could be used.

McQuade said, "We have not done a complete survey of colours, but do not see any reason why the full FDA approved dye rainbow is not accessible."

The researchers report that different concentrations of the gelling agent produced gels with different physical properties as noted in the American Chemical Society’s journal Biomacromolecules. This was demonstrated by a low concentration of calcium chloride of 0.1 moles per liter that was brittle and easily removable but the higher concentration gelling agent of 2.0 moles per liter adhered well and was not easy to remove.

Calcium alginate has long been used in the food industry as a thickening agent, and annual sales of sodium alginate are supposed to exceed $100m annually.

McQuade said that the research has mainly received recognition in the turf spraying industry. However, since these hydrogels are prepared from materials that are cheap, readily available and environmentally friendly, this could be of interest to the food and dietary supplements industries.

He said, ‘We are still in the initial phases of discovery and we feel that there are many yet to be tapped applications. We think that this is an exciting new technology that has not been fully exploited.’