The Effect of Different Disinfectants on the Microbial Load of Lettuce

Abstract

Aim: This research was planned to examine the effects of various disinfectants used for raw vegetable disinfection in institutional food services on Enterobacteriaceae and total coliform bacterial load. Material and Methods: Lettuce samples were collected in Ankara wholesalers. Whole or sliced into thin strips 2 cm thick samples of lettuce were disinfected with 50 or 200 ppm chlorine solutions at 5 minutes and 15 minutes and 0.1% calcium oxide for 5 minutes. Results: A reduction of 4.97 and 5.31 (log kob/g) in the Enterobacteriaceae load was determined respectively when both whole and sliced lettuce samples were disinfected with 50 ppm chlorine at 5 minutes solutions while the reduction of total coliform bacteria load (log kob/g) was determined as 4.11 and 4.31 respectively. Whole or sliced lettuce samples that disinfected with 50 ppm chlorine solutions for 15 minutes determinated a reduction in Enterobacteriaceae (log kob/g) as 5.29, 5.48 and total coliform bacteria (log kob/g) as 4.20, 4.58 respectively. No Enterobacteriaceae and total coliform were detected with 200 ppm chlorine and calcium oxide disinfection practices. At the end of disinfection procedures microbial reductions were not found statistically significant between whole and sliced lettuce samples. Conclusion: Chlorine is commonly used effective disinfectant in institutional food services. However because of its possible health risks, a natural product known as a food additive (E529), called calcium oxide, may consider as a better alternative for vegetables disinfections. Further research is needed in this field.