Document Type
Article
Publication Date
5-1-2020
Abstract
Sanitizer wash may induce bacterial pathogens on produce surfaces into a viable but-nonculturable (VBNC) state and may go undetected by conventional plating methods. This study investigated the effect of chlorine and lactic acid on the viability of E. coli O157: H7 on spinach leaves right after the treatment and during refrigerated storage using propidium monoazide staining and real-time PCR (PMA-qPCR). Baby spinach leaves inoculated with E. coli O157: H7 were washed with chlorine (100 ppm) and lactic acid (0.5%) for 5 min and 3 min, respectively. The residual effect of the treatments was examined by inoculating the sanitizer-treated leaves with the pathogen and allowing them to sit for up to 48 h at 4 °C. Chlorine and lactic acid wash resulted in the reduction in viable E. coli O157: H7 counts by 2.51 and 3.43 log CFU/g, respectively. After 48 h of refrigerated storage, viable E. coli O157:H7 population was significantly reduced by 2.86 log CFU/g on chlorine-treated leaves and by 4.42 log CFU/g on lactic treated leaves. This study emphasized the potential effect of chlorine and lactic acid in reducing viable E. coli O157: H7 population on produce surfaces.
Publication Source (Journal or Book title)
LWT
Recommended Citation
Chhetri, V., Han, Y., Janes, M., & Adhikari, A. (2020). Evaluation of viability of E. coli O157: H7 on chlorine and lactic acid treated spinach leaves using combined propidium monoazide staining and real-time PCR. LWT, 125 https://doi.org/10.1016/j.lwt.2020.109259