Improved traceability and greater consumer convenience are the benefits claimed for new laser etching technology which allows information to be marked indelibly on the surface of fruit and vegetables. Jan Narciso, microbiologist at the ARS Citrus and Subtropical Products Laboratory, Winter Haven, Florida, told FoodProductionDaily.com: “This technology uses a carbon dioxide laser beam to etch information on the first few outer cells of fruit and vegetables.” Once etched, the information cannot be distorted, peeled off, washed off or changed.The indelible mark offers a new, more reliable and quicker way to improve the security of produce and to check its progress through the food chain or at supermarket checkout lines, claimed the scientist.
The conventional way of attaching information to fruit and vegetables is with sticky paper labels. Known as Price Look-up (PLU) stickers, these sometimes prove unpopular with consumers, producers and distributors.
Track produce
For example, grapefruit has long been labelled with PLU stickers which can easily become detached making it more difficult to track produce back to the source. Alternatively, the labels can adhere to produce too tightly making it difficult for consumers to remove them.
Also, sticky labels can mar the fruit and stick to one another during storage or distribution. The etched information, sometimes supplemented by the injection of food dyes, could include country of origin, and a producer reference number. Federal US regulations require all imported produce to be labeled with the country of origin.
“We expect to receive approval from the Food and Drug Administration (FDA) imminently for this laser etching technology (which will open the way for its commercial use),” said Narciso.
According to her research, carbon dioxide etching does not compromise the quality or durability of the treated fruit and vegetables. “Etching fruit peel does not increase water loss or facilitate the entrance of food pathogens or post harvest pathogens if the laser label is covered with wax,” said Narciso.
Food pathogens
Wax treatment may be unnecessary, she continued. The tiny holes etched into the grapefruit peel are effectively sealed by the carbon dioxide which prevents decay and the entry of food pathogens. Even when fruit was inoculated with decay organisms and then etched with the laser, no pathogens were found in the peel or the fruit interior.
But wax coverage may be necessary to eliminate water loss, admitted Narciso. The laser etching process takes seconds and is much quicker than attaching sticky labels, she added. In addition to grapefruit, testing is also being conducted on other citrus fruits, tomatoes, garlic and avocados.
The technology was invented by former University of Florida scientist Greg Drouillard who now works with the agricultural co-operative Sunkist Growers. Meanwhile in Japan, apples have been sold with scannable bar coding etched into the wax on their skin.
