Edible holograms could be used to decorate the food of the future

A team of researchers have developed decorative, edible holograms that could also prove that the food item isn’t a counterfeit product

Spotted: Mass-produced holograms have been around since the mid-1980s, and since then have become common on daily items such as credit cards and currency. Now, researchers are kicking it up a notch and are developing edible holograms. A lot of the time, these are used for decorative purposes, but although scientists have successfully moulded them into certain types of chocolate, a new mould has to be created for each design. With this in mind, a team of researchers at the United Arab Emirates’ Khalifa University set out to develop a safe and more versatile alternative to applying holograms to food.

The team started by mixing corn syrup and vanilla with water, then let the solution dry into a film, which was then coated with a thin layer of synthetic black dye. Making use of laser interference patterning, an alternative technique for producing micro and nanoscale structures on metallic, semiconductor and polymer surfaces, the layer was gradually etched away. A series of nanoscale raised lines were then left behind, forming what is known as a diffraction grating.

The grating allows light to pass through it and reflect off the corn syrup and vanilla film, creating a rainbow-coloured pattern. Just like a hologram, the visible colours change depending on the angle they are held in. The range and intensity of the colours can also be altered by tweaking the space between the lines, or by varying the sugar content of the film between 25 and 175mg. 

In order to prepare holographic food for the market, scientists are now trying to adapt the technology to work with food-grade dye, to replace the already non-toxic dye used to create edible holograms.

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