Efficacy of cetylpyridinium chlorine on Salmonella typhimurium and Escherichia coli O157 : H7 in immersion spray treatment of fresh-cut lettuce

摘要

Fresh-cut lettuce inoculated with Salmonella enterica serovar Typhimurium and Escherichia coli O157:H7 was treated using cetylpyridinium chlorine (CPC) solution in a laboratory-scale immersion spray system. With 0.7 kg/cm(2) spray pressure and 1.5-min spray time (ST), both bacteria were significantly reduced (P < 0.05) in 0.1% to 0.3% CPC spray treatments, compared with water spray controls. At the same ST, increasing spray pressure from 0.7 to 2.1 kg/cm(2) further reduced bacteria by 0.5 to 1.5 log colony-forming units (CFU)/g. The 0.2% and 0.3% CPC treatments resulted in the greatest reduction of S. serovar Typhimurium and E. coli O157:H7, respectively. Similar bacterial reduction could be achieved using shorter ST with extended post-spray exposure time. No color change on the lettuce was observed after CPC treatment. [References: 24]