Those small and sometimes inconvenient sticky labels on produce may eventually be replaced by laser "tattoo" technology now being tested by Agricultural Research Service and University of Florida scientists. Called laser etching, the new technology puts a tattoo on grapefruit and other produce so it can be identified at the supermarket checkout lines.
In research, a carbon dioxide laser beam was used to etch information into the first few outer cells of the fruit peel. The mark can't be peeled off, washed off or changed, offering a way to trace the fruit back to its original source. Testing shows the use of wax as a protectant may be unnecessary, since the tiny holes etched into the grapefruit peel are effectively sealed by carbon dioxide, preventing decay and food pathogen entry. However, wax coverage is recommended to eliminate water loss.
The researchers 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. Testing is also being conducted on tomatoes, avocado and other citrus fruits. The process would have to be approved by the Food and Drug Administration before it could be used commercially.