powerful oxidizing treatment and is effective against
chlorine-resistant decay microbes and foodborne
pathogens, acting far more quickly than permissible
concentrations of chlorine. This may be a distinct
advantage for cooling or wash procedures with short
contact times. Ozone oxidative reactions create far
fewer disinfection by-products (e.g., trihalomethanes
are a health and environmental concern) than chlorination.
You may decide to use ozonation rather than chlorination
in your organic postharvest operation despite
capital and operating costs that are higher than for chlorine
or other available methods.
Ozone must be generated on-site at the time of use
and has a very low stability, as short as 20 minutes even
in clear water. Clear water is essential for optimal performance,
and adequate filtration of input or recirculating
water is needed. Depending on scale and ozone
generation output, complete-system costs start at about
$10,000. Small-scale units are available for a few thousand
dollars and are suitable for limited water use and
small-batch applications. For specifications and installation,
consult an experienced ozone service provider.
Food-grade hydrogen peroxide (0.5 to 1%) and peroxyacetic
acid are additional options. In general, peroxyacetic
acid (PAA) has good efficacy in water dump
tanks and water flume sanitation applications. PAA has
very good performance, compared to chlorine and