Ozonation as a clean technology for fresh produce industry and environment: sanitizer efficiency and wastewater quality

Abstract

Aims: Inactivating microbial contaminants in fresh produce commonly uses chlorine washing. The effectiveness of ozone was explored as an alternative to chlorine in produce washing for ensuring microbial safety while maximizing water reusability. Methods and Results: An ozone washing system was designed to permit continuous addition of contaminated produce and the reuse of washing water. The effectiveness of ozonation (<2 mg l À1 ) was determined using Bacillus subtilis spores as a stricter measure of efficiency with processing time of 10 min. As a comparison, chlorine (c. 100 mg l À1 ) was tested in parallel. Water quality characteristics, including chemical oxygen demand, total suspended solids, disinfectants concentration and microbial reduction were measured. Ozonation showed an average of 1Á56 log reduction of B. subtilis spores on lettuce, while chlorination achieved a 1Á30 log reduction. The effluents after ozonation demonstrated improved water quality, both in physicochemical quality and microbial quality compared to chlorination. Conclusion: Aqueous ozone treatment is effective against microbial contaminants on fresh produce and enables extended use of washing water. Significance and Impact of the Study: The results provide significant data about ozone disinfection efficacy and its impact on the water reusability, which can facilitate the ozone utilization in the fresh produce production as an environmental friendly alternative.

Effects of Selected Bio‐Fungicide and Fungicide Treatments on Shelf Life and Quality Characteristics of Romaine Lettuce (Lactuca SativaL.)

“…The effectiveness of ozonation (<2 mg/L) was determined using B. subtilis spores as a stricter measure of efficiency with a processing time of 10 min (Rosenblum et al . ).…”

Postharvest washing as a critical control point in fresh produce processing: alternative sanitizers and wash technologies

“…Aqueous ozone does not result in higher log reductions on fresh produce compared with hypochlorite, although does have the benefi t of not producing DBP (Rosenblum et al , 2012). Yet, because of the poor solubility of ozone, there can be issues with off-gassing into the environment, in addition to corrosion of wash tanks and negative impact on the sensory characteristics of the product (Kim et al , 2003).…”

The Sustainability of Agro-Food and Natural Resource Systems in the Mediterranean Basin

“…After washing, fruits were also stored in an intermittent ozone air mixture (0.25 ppm ozone). O 3 is effective at lower concentrations (1-5 ppm) and shorter contact times (1-5 min) than chlorine (Srey et al 2013), and it can react with organic matter up to 3,000 times faster than chlorine (Rosenblum et al 2012). ) or as miscellaneous molds of unidentified fungi.…”