The Effect of Water Pressure and Chlorine Concentration on Microbiological Characteristics of Spray Washed Broiler Carcasses

The objective of this study was to evaluate the efficiency of water pressure and concentration of dichloromethane after the evisceration system under the fecal decontamination of chicken carcass surfaces with and without apparent contamination. From a total of 322 carcasses, 50% were intentionally added chicken droppings in an area of more than 2 cm(2) and the rest of carcasses were kept without fecal inoculation. Escherichia coli and Enterobacteriaceae counting was carried out in samples immediately after the inoculation (initial counting) and after different treatments. Treatments consisted of water with different pressures (1.5, 3.5 and 5.5 Kgf/cm(2)), and the addition of a technological adjuvant (dichloride) at the concentrations of 0, 5 and 10 ppm. The results were validated using 40 chicken carcasses for each treatment by means of a 22 factorial statistical design. The results showed no significant differences (P<0.05) between the carcasses with and without initial apparent fecal contamination after passing through the washing nozzles, related to the E. coli and Enterobacteriaceae countings and the visual characteristics (32 judgers) of the products. The binomial pressure-adjuvant concentration influenced the result of microbiological analyses of chicken carcasses; the water pressure demonstrated higher influence compared to the adjuvant concentration. Most of the treatments showed satisfactory results on the fecal decontamination.