Chlorine is a standard antimicrobial used in poultry processing plants because of its ability to effectively kill a wide range of microorganisms on carcasses, in processing water and on processing equipment. Methods of chlorination can be complex, however, as safety issues and storage space for materials/chemicals used must be considered. Acidic electrolyzed oxidizing (EO) water is produced by the electrolysis of dilute solutions of sodium chloride or other salts using EO water generators. The antimicrobial properties of EO water are a result of the low pH, high oxidation-reduction potential (ORP) and elevated levels of hypochlorous acid produced during electrolysis. Salts are the only chemical used in this process, therefore reducing the need for storing other potentially dangerous chemicals. This study was conducted to compare the ability of chlorinated and EO water to reduce the population of spoilage microorganisms on processed broiler carcasses.

In this study, eviscerated broiler carcasses were collected at a commercial processing facility prior to the final bird wash. The carcasses were then either sprayed with tap water (pH 8.0), a 50-ppm chlorine solution (pH 8.2), or acidic EO water (pH 2.4) for five seconds at 80 psi in an inside-outside bird washer. Immediately after treatment, samples for microbial analysis were collected using a whole-carcass rinse. Remaining carcasses were stored at 4 C for three, seven or 14 days before microbial analysis. The populations of psychotrophic bacteria and yeasts in the carcasses were enumerated and counted.

Fewer bacteria were recovered on day 14 from carcasses sprayed with EO water compared to either chlorinated or tap water.

Spraying carcasses with acidic EO or chlorinated water resulted in significantly fewer psychotrophic bacteria than when spraying with tap water. Furthermore, the number of bacteria recovered from the carcasses sprayed with either tap water or chlorinated water significantly increased by day 7 and day 14, whereas bacteria recovered from carcasses sprayed with EO water did not significantly increase with storage until day 14. There were also fewer bacteria recovered on day 14 from carcasses sprayed with EO water compared to either chlorinated or tap water. The authors explained this by the low pH, high ORP and hypochlorous acid concentration of the EO water. Similar results have been reported by other researchers when evaluating the effectiveness of EO water against Salmonella typhimurium. In this study, the predominant psychotrophic bacteria from day 7 to day 14 were identified as Pseudomonas spp.

Yeasts were also affected by the treatments in this study. Spraying chlorinated water on broiler carcasses reduced the number of yeasts compared to carcasses sprayed with tap water. Spraying EO water on broiler carcasses further reduced the number of yeasts as indicated by significantly fewer recovered yeasts in the EO treatment compared to the carcasses sprayed with chlorinated or tap water. The number of yeasts recovered increased with time in the broilers sprayed with either tap or chlorinated water; however, there was no increase in yeasts in broilers sprayed with EO water. In this study, Candida spp. was the most prevalent yeast recovered in all of the samples.

The results of this study suggest that the use of acidic electrolyzed oxidizing water may be used to reduce the population of spoilage microflora on broiler carcasses and authors suggest that it may be used as an alternative to chlorinated water. Authors state that using EO water as an alternative can reduce safety hazards associated with water chlorination.

A. Hinton, Jr., J.K. Northcutt, D.P. Smith, M.T. Musgrove and K.D. Ingram; 2007. Spoilage microflora of broiler carcasses washed with electrolyzed oxidizing or chlorinated water using an inside-outside bird washer. Poultry Science, 86: 123-127.