Critical Control Points for Monitoring Salmonellae Reduction in Thai Commercial Frozen Broiler Processing

Abstract

Since 1998, pathogen reduction regulations for poultry have been enforced through the Food Safety and Inspection Service of the U.S. Department of Agriculture and through hazard analysis critical control point evaluation. This enforcement has focused attention on pathogen control and sanitation in the United States and in other countries, including Thailand. The objective of this study was to evaluate reduction in salmonellae achieved by Thai commercial exporters of frozen broiler chickens. A total of 188 broiler samples and 56 water overflows from two chillers were collected from nine processing lines of frozen broiler exporters at four identified critical control points (CCPs): CCP1, washing; CCP2, chilling; CCP3, deboning; and CCP4, packing. Samples were screened for salmonellae by enzyme-linked immunosorbent assay, and bacterial identification was confirmed through biochemical and serological patterns. The overall prevalence of Salmonella was 24.6% (60 of 244 samples), with 12 serovars identified. Salmonella Albany was predominant (33.3%, 20 of 60 samples). Salmonella prevalence was 20.0% (6 of 30 samples) prior to CCP1 and was 12.5% (4 of 32), 22.7% (15 of 66), 33.3% (10 of 30), and 23.3% (7 of 30) after CCP1, CCP2, CCP3, and CCP4, respectively. The critical limit was 20% positive samples, and three CCPs failed to meet standards. Three corrective interventions were used at CCP2: 30 mg/liter hydrogen peroxide, 0.5% peracetic acid, and 125 mg/liter ozone. After these interventions, 65 broiler samples were collected for analysis of Salmonella prevalence. Results were compared with those obtained after chlorine was applied individually as a control. The Salmonella prevalences after intervention treatments were 16.0% (4 of 25), 5.0% (1 of 20), and 15.0% (3 of 20) after hydrogen peroxide, peracetic acid, and ozone treatments, respectively. All values were below the 20% critical limit, and the application of 0.5% peracetic acid produced significantly lower prevalences (P < 0.05). Repeated sampling after 1 to 4 months indicated that sanitation at these three plants was inconsistent (P < 0.05).