Microbiological impact of spray washing broiler carcasses using different chlorine concentrations and water temperatures

Abstract

A study was conducted to investigate the microbiological impact of spray washing broiler carcasses with chlorinated water (0 or 50 ppm) at different temperatures (21.1, 43.3, or 54.4 degrees C). A whole carcass rinse (WCR) was performed on each carcass before (control) and after spray washing (final). After the control WCR, carcasses were inoculated with 0.1 g of cecal material containing 2 x 10(5) cells per gram of Campylobacter and 2 x 10(5) cells per gram of nalidixic acid-resistant Salmonella. Carcasses were held at room temperature for 12 min before washing in an inside-outside bird washer (80 psi for 5 s). Chlorine level and water temperature had no effect on total aerobic bacteria, Escherichia coli, or Campylobacter numbers recovered from the final WCR. Levels of bacteria found on carcasses before and after washing were 4.6, 3.6, and 3.5 log10 cfu/mL rinse for total aerobic bacteria, E. coli, and Campylobacter, respectively. Average counts for nalidixic acid-resistant Salmonella after washing were 3.1 log10 cfu/ mL rinse irrespective of water temperature or chlorine level (P < 0.05). In addition, chlorine level and water temperature had no effect on the breast skin color, with average values of L* = 66.6; a* = -0.09; b* = -0.05 (P < 0.05). Under the conditions outlined in the present study, adding chlorine and/or elevating the water temperature during spray washing in an inside-outside bird washer did not enhance the removal of bacteria from broiler carcasses and had no effect on carcass skin color.