February, 1998

 

UV pasteurization could be alternative for small cider makers

 

by Linda McCandless

Cornell News Service

 

Ultraviolet light may be the answer to E. coli O157:H7 contamination of fresh cider and fruit juices, according to Cornell University microbiologist and food safety expert Randy Worobo. Speaking before a group of about 150 apple growers and cider producers at the New York State Horticultural Society's annual meeting in Rochester in mid-January, Worobo unveiled a feasible alternative to thermal pasteurization that has shown very promising results in preliminary testing.

Worobo and two engineers from the Rochester-based firm, FPE, Inc. have come up with a new design for a UV pasteurization unit that should be perfect for small cider producers. Worobo reported that, "the new unit is about one-quarter of the price of a thermal pasteurization unit, small, economical to run, and very user-friendly."

In the new process, a thin film of cider is pumped past UV light at the rate of about two gallons per minute. Preliminary tests have shown that this particular design reduces E. coli contamination from 100,000 microorganisms per ml to one organism per ml. Tests may prove effective against other pathogens as well, according to Worobo.

Nationwide isolate outbreaks of contamination of fresh apple cider and fruit juices by the bacteria E. coli 0157:H7 have been causing health problems and creating a crisis of confidence among consumers in the past few years. This virulent strain of E. coli (O157:H7) was first identified in 1982. Producers and consumers are clamoring for more information and recommendations for safe production practices. Last year, thermal pasteurization was the process of choice, but the thermal pasteurization units cost about $30,000 and are out of the reach of most small producers who rely on a four-week season in the fall to cover the costs of production.

"Preliminary tests indicate UV light causes no sensory changes in the juice," said Worobo. Further testing on feasibility and effectiveness is being conducted by the two engineers who developed the technology, Patrick Borrelli and Phil Harman, and Worobo, in conjunction with food specialists at the New York State Agricultural Experiment Station in Geneva, who are evaluating the sensory data.

The unit could cost as little as $6,000. FPE, Inc. has applied for a patent.



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