Water used to wash fresh produce is often treated with chemical disinfectants to prevent cross-contamination and reduce microbial growth. The wash system is a dynamic process in which the microbial load of the incoming raw material, the concentration of sanitizer, and the organic matter change constantly along the production day. Regarding the organic matter of the wash water, the major factors that contribute to the organic load include the organic matter present in the dirt and soils, on the vegetable or fruit surface, and the organic materials released from the cut edges or damaged areas. For antimicrobial agents added to the wash, if the concentration is not sufficiently replenished, it usually declines rapidly as a result of its reaction with soluble organic materials present in the wash water. In the presence of an insufficient level of antimicrobial agent, microbial pathogens can remain viable in the wash water and transferred to the uncontaminated product. In the presence of a sufficient level of antimicrobial agent, microbial cells that are released from the contaminated product are immediately inactivated in the wash water, thus preventing cross-contamination.[1]
There are different commercially available agents for wash water disinfection, including chlorine derivatives such as sodium hypochlorite, calcium hypochlorite, electrolyzed water (EW), and chlorine gas. Chlorine dioxide (ClO2) is a neutral chlorine compound that is very different from elementary chlorine both in its chemical structure as in its behavior.