Skip to main content
ARS Home » Southeast Area » Raleigh, North Carolina » Food Science Research » Research » Publications at this Location » Publication #68296


item Fleming, Henry

Submitted to: Applied Engineering in Agriculture
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 8/20/1996
Publication Date: N/A
Citation: N/A

Interpretive Summary: Pathogenic and spoilage microorganisms may contaminate fresh produce, which makes it desirable to wash and cool the produce to reduce their numbers. Although chlorine has long been added to washing and cooling water to suppress microorganisms, the value of its use has been questioned because of the relatively high concentrations required (greater than 100 parts per million) and the potential for formation of compounds implicated in cancer. We found that only 1.3 parts per million of chlorine dioxide is sufficient to kill and prevent buildup of microorganisms in the water used to hydrocool fresh pickling cucumbers. Chlorine dioxide does not react to form the potential carcinogens, and it is not as corrosive to processing equipment as is chlorine. Thus, chlorine dioxide is recommended to be added to the washing and hydrocooling water of whole pickling cucumbers and other produce.

Technical Abstract: Typical operating parameters for a chlorine dioxide generator installed on a hydrocooler (7560 L water capacity) for pickling cucumbers were ascertained. The recycled hydrocooler water (2-8C) was maintained at 1.3 ppm chlorine dioxide to effectively control microorganisms. The rates of chlorite, hypochorite, and hydrochloric acid use to generate chlorine dioxide were linearly related to the quantity of cucumbers hydrocooled for operating runs of 172 and 304 field boxes (705 L, 20 bushels) intermittently hydrocooled over two 20-hr periods. Use rates were 0.0621 to 0.070 (chlorite), 0.056 to 0.065 (hypochlorite) and 0.023 to 0.026 (hydrochloric acid) kg/box hydrocooled. Materials cost for chlorine dioxide treatment was $0.24 to $0.29 per box. Optical density increased and total solids accumulated in the hydrocooler water in direct proportion to product throughput for both tests.