Changes in the effectiveness of chlorine treatments during colonization of Salmonella Montevideo on tomatoes
Posted: February 12th, 2010 - 12:21pm
Source: Journal of Food Safety
Inactivation of pathogens in produce is an essential approach for mitigating the risk of disease. A study was undertaken to compare the efficacy of chlorine to kill Salmonella Montevideo cells during colonization on the surface of tomatoes. Tomatoes (Lycopersicum esculentum) were spot-inoculated with 100 µL (ca. 8 log cfu) of S. Montevideo. To promote attachment, inoculated fruits were incubated for 90 min at 22C, then washed to remove unattached cells and stored at 30C and 97% relative humidity for up to 10 days. Periodically, tomatoes were treated with chlorine (1000 or 200 mg/L) or water (control). On day 0, treatments with 1000 or 200 mg/L of chlorine, and water reduced the pathogen population by approximately 5.0, 4.5 and 0.4 log cfu/tomato, respectively. The inactivation efficacy of the sanitizers decreased as the storage time elapsed. By the 7th day, the populations recovered from tomatoes treated with water and disinfectants were not significantly different (P < 0.5).