Food scientists from the University of Birmingham in the U.K and Khalifa University of Science and Technology in the United Arab Emirates have developed a technique for printing nanostructured holograms on films of dried corn syrup.

Using vanilla, corn syrup and water, the food scientists dried the solution into a film that they then coated in a black, non-toxic dye. Once coated, the team then employed a direct laser interference patterning technique to etch off the dye.

Nanostructures (yellowish-green images; scale bar, 5 μm) were patterned onto dried corn syrup films, producing edible, rainbow-colored holograms (scale bar, 2 mm). Source: ACS Nano

According to the team of scientists, this etching process left behind raised, nanoscale lines that created a diffraction grating. When the grating was exposed to light, the nanoscale lines diffracted the light, which formed a rainbow pattern wherein different colors appeared at various angles according to how the nanostructure was viewed.

Additionally, the team demonstrated that it could manipulate the range of colors and their intensities by modifying the line spacing within the film’s grating.

The researchers believe that the technique could be used for applications such as food labeling and food safety. In the meantime, the team expects to modify the technique to replace the black dye with a food-grade dye.

The research appears in the journal ACS Nano.