Scientists at the Agricultural Research Service and University of Florida have devised a better idea -- and it comes with the help of lasers.
Laser etching that can effectively 'tattoo' produce has been found to be effective to help identify fruit at the supermarket. Invented by former University of Florida scientist Greg Drouillard -- now with Sunkist Growers -- the technology helps do away with sticky labels that can mar the fruit's skin (and stick to each other in storage), and can easily be removed, the scientists say.
Microbiologist Jan Narciso at the ARS Citrus and Subtropical Products Laboratory in Winter Haven, Fla., and Florida researcher Edgardo Etxeberria first thought to apply the laser technology to fruit.
The system works by using a carbon dioxide laser beam to etch information into the first few outer cells of the fruit peel.
The "tattoo" can’t be peeled off, washed off or changed, preserving provenance. Better still, the permanent etching - hence "tattoo" -- does not increase water loss, nor the entrance of food pathogens or postharvest pathogens.
The only catch? The laser label must be covered with wax.
Well, maybe. Testing on a grapefruit has shown that the wax may be unnecessary, since the tiny holes etched into the fruit's peel "are effectively sealed by the carbon dioxide," stopping decay and food pathogens. (Wax coverage is still recommended to prevent water loss.)
To test for 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.
So how does it work? The laser actually cauterizes the peel, making it impenetrable to microorganisms.
But a grapefruit and an apple are two different challengesm so testing is currently being conducted on tomatoes, avocado and other citrus fruits.
Naturally, the process still must be approved by the U.S. Food and Drug Administration before it could be used commercially.