A Bisulfate of Soda and Peroxyacetic Acid Solution Reduces Salmonella on Fresh-Cut Spinach

Fresh produce is commonly implicated in foodborne illness outbreaks, including outbreaks of Salmonella infection. Chlorine is commonly added to produce wash water to control pathogen cross-contamination in water and is moderately efficacious because of limitations associated with organic matter and pH requirements. This study was conducted to evaluate a bisulfate of soda-peroxyacetic acid (SP) wash for fresh-cut spinach inoculated with Salmonella at > 6 log CFU/g. An unwashed control was compared with produce washed with gentle agitation in SP (80 ppm of peroxyacetic acid plus 0.5% [w/v] bisulfate of soda), chlorine (150 ppm, pH 7.0), or tap water. Spinach was stored in microperforated retail display bags at 7°C, and Salmonella levels were enumerated on days 0, 1, 3, 5, and 10 on xylose lysine tergitol-4 agar plus a tryptic soy agar overlay. SP was the most effective wash, reducing Salmonella by 1.8 log CFU/g (P < 0.05) in comparison with the control. Washing with SP significantly reduced Salmonella populations on fresh-cut spinach and may serve as an effective alternative to chlorine washes.