WASHINGTON - Those small and inconvenient sticky labels in illegible print on consumer items like fruits are likely to be replaced by laser ‘tattoo’ technology, which is currently undergoing tests.

Called laser etching, the new technology puts a tattoo on grapefruit and other produce so it can be identified at the supermarket checkout lines.

The technology was invented by former University of Florida (UFL) scientist Greg Drouillard, now with Sunkist Growers.

Grapefruit has always been labelled with sticky paper labels that mar the fruit and stick to one another in storage. The labels are also easily removed, making it more difficult to track a piece of produce back to the source if the need arises.

Microbiologist Jan Narciso at the Agricultural Research Service (ARS) Citrus and Subtropical Products Lab and UFL researcher Ed Etxeberria investigated laser technology as an alternative to sticky paper labels.

A carbon dioxide laser beam was used to etch information into the first few outer cells of the fruit peel. The mark cant be peeled off, washed off or changed, offering a way to trace the fruit back to its original source.

This permanent etching into the fruit peel does not increase water loss or the entrance of food pathogens or post-harvest pathogens if the laser label is covered with wax.

Further testing shows the wax may be unnecessary, since the tiny holes etched into the grapefruit peel are effectively sealed by the carbon dioxide, preventing decay and food pathogen entry.

However, wax coverage is recommended to eliminate water loss. In testing for fruit decay, the fruit was inoculated with decay organisms and then etched with the laser. No pathogens were found in the peel or the fruit interior, said an ARS release.

Narciso and Etxeberria found that the laser cauterizes the peel, much like when a laser is used on human skin. The cauterized area is impenetrable to pathogens and decay organisms and resists water loss.

The research was published in HortTechnology.