In a bid to extend fresh produce shelf life on board Navy aircraft carriers, Woburn, Mass.-based Primaira LLC has partnered with researchers at the Natick Soldier Research Development and Engineering Center to develop an ethylene control device.
Some fruits notably bananas and apples naturally produce ethylene, which speeds ripening and spoilage. It affects produce items stored nearby.
The device uses ultraviolet enhanced ozone technology and is designed to be compact and low-cost, said Peter Lavigne, a chemical engineer with the center"s Combat Feeding Directorate.
It oxidizes ethylene to carbon dioxide and water vapor, and the ultraviolet light destroys airborne microbes, spores and fungus.
Using ultraviolet reduces the maintenance required by alternative methods, said Lou Jamieson, a Navy project officer on the directorate"s systems and engineering staff and a retired Navy master chief petty officer.
"The use of ethylene and moisture sorbent blankets and pellets to control this problem poses significant logistic challenges associated with stocking, maintaining, and disposing of these materials," Jamieson said.
The device runs automatically and requires only an annual replacement of the ultraviolet lamp and screen.
Long periods at sea, sometimes with unforeseen mission changes, made preserving freshness and minimizing maintenance a priority for the Navy.
Tests showed that on a 2,000-pound mixed load of apples, iceberg lettuce, broccoli, cantaloupes and honeydew melons in a 270-cubic-foot refrigerated container, the technology added seven-plus days to shelf life, Jamieson said. It reduced ethylene concentration from 60 parts per million to below two.
Based on such results all 11 Navy aircraft carriers are expected to be fitted with the ethylene control device over the next two years, he said. Two carriers, the Eisenhower and Carol Vinson, have already used them.
The Navy's experiments with ethylene control were announced in 2012.
The technology was developed under an Army Small Business Innovation Research contract awarded to Primaira and managed for military and commercial application by the Natick center. The center is part of the U.S. Army Research, Development and Engineering Command, which develops technology and engineering for soldiers.
Primaira manufactures Bluezone fresh preservation technology it initially developed for U.S. Army applications.