Food Engineering

UV Light Process Extends Shelf Life

March 28, 2003


California Day-Fresh Foods Inc., (CDF) a subsidiary of Chiquita Brands International, Glendora, CA, is on the forefront of R&D and commercial application of ultraviolet light processing for fresh juice. In July 1999, the company submitted a petition to the FDA for use of a modular UV light-processing unit developed by James E. Cruver of Salcor Inc., Fallbrook, CA. CDF will use the “Light Processed System,” to treat its fresh, refrigerated juice lines—Naked Juice and Ferraro’s Earth Juice. At press time, CDF was expecting FDA approval.

“Test results have shown that the Light Processed System, in conjunction with CDF’s state-of-the-art Hazard Analysis and Critical Control Point (HACCP) program, reduces the threat of potentially harmful bacteria to levels well within those mandated by new FDA regulations,” says Cruver, who has a patent pending on the technology.

Fresh juice enters the UV module, which contains a length of transparent Teflon™-coiled, one-inch diameter tubing sufficient for seven gallons of juice. The tube is enclosed and surrounded by UV lamps and reflectors. Its low-pressure mercury lamps generate 90 percent of their energy at 253.7-nanomer wavelength with the remainder falling within 240 and 260 nanometers. Cruver’s studies show optimal inactivation of viruses and bacteria at this wavelength. As the juice tumbles through the tubing, it is completely exposed to the UV light, which effectively fuses harmful bacteria’s reproductive DNA structure, rendering them incapable of reproducing. Exposure time is generally one minute.

“We produce about 25,000 gallons of juice per day for retail and foodservice accounts,” says Dave Sperry, CDF president. “We chose the Salcor system because of its proven effectiveness in bottled water applications. Although we do not have an exclusive arrangement with Salcor, we have worked hand-in-hand with Dr. Cruver for the past two years perfecting this process for juice.

“We are one of the first food manufacturers to qualify for FDA’s expedited approval process and therefore anticipate clearance as early as October. Once approved, we would apply this process to all of our vegetable juices currently available for distribution.”

“Reducing natural micro-organisms in the juice allows shelf life extension,” notes Dominick Marlia, QA manager. “We are primarily targeting Salmonella, Listeria, and E. coli. Nutrients and organoleptic properties of the juices stay intact, and this process does not change the juice’s natural flavor, texture, color or enzymatic properties. Retailers have shown great enthusiasm for these products because they see the value of non-heat-treated, chilled juices.

“Currently, refrigerated shelf life for cold-filled products is five days for neutral pH vegetable juices, and 15 days for high-acid fruit juices,” adds Marlia. “But with our Light Processed System, tests indicate we will be able to double refrigerated shelf life for some of these products. This will allow us to expand our distribution areas considerably.”