@inproceedings{2984573,
  abstract     = {{A lettuce (Lactuca sativa) washing process was simulated to assess chlorine as a disinfectant for maintaining the microbial water quality “clean” i.e. to prevent water becoming a vehicle for transmission of unacceptable levels of micro-organisms to the lettuce. Cut lettuce leaves were inoculated overnight with E.coli O157 to obtain ca. 4.0 log CFU/g, and subsequently washed. The washing process consisted of washing portions of 50 g of lettuce for one minute. The process was executed for 1 hour by taking lettuce portions of 50 g, and continuing to pass each subsequently  through the same washing bath to obtain a final product-to-water ratio of 0.5. kg/L. Each portion of lettuce was rinsed after washing. The pH of the washing water was reduced to 6.5 and free chlorine was continuously added to maintain 1 mg/L of free chlorine in the water. The experiment was performed in i) tap water and ii) in artificial process water, including lettuce extract, the latter with COD values of 500 (C500) or 1000 mg O2/L (C1000). In the absence of chlorine, the E. coli O157 levels rapidly increased in the wash water and eventually reached 5.3 ± 0.4 log/100 mL. When maintaining 1 mg/L of free chlorine, the contamination could be controlled to 2.2 ± 0.05, 1.2 ± 0.6 and 1.3 ± 0.4 log CFU/100 mL in tap water, C500, and C1000 respectively. Chlorination breakpoint and cumulative chlorine dose positively correlated with the COD load of the water and this higher chlorine consumption resulted in increased total trihalomethanes concentrations in the water: <LOD, 27.8 ± 5.4 and 124.5± 13.4 µg/L, the latter exceeding the amount allowed in drinking water in the EU. However, on the lettuce no detectable amounts were observed in all cases. This experiment shows that low amounts of chlorine are effective for maintaining a “clean” water quality. Nevertheless, the correlation of trihalomethanes with COD load illustrates the importance of the physicochemical quality and suggests the possible use of pre-treatments to lower the COD load.}},
  author       = {{Van Haute, Sam and Sampers, Imca and Holvoet, Kevin and Uyttendaele, Mieke}},
  booktitle    = {{FoodMicro 2012, Abstracts}},
  language     = {{eng}},
  location     = {{Istanbul, Turkey}},
  pages        = {{331--331}},
  title        = {{Chlorine as lettuce wash water disinfectant with respect to the physicochemical quality and the chemical quality}},
  year         = {{2012}},
}