18D-35

S.-Y. LEE¹, P. M. Gray², W. Lu¹, R. H. Dougherty², J. Busboom³, and D.-H. Kang². (1) Food Science and Human Nutrition, Washington State Univ., PO Box 646376, Pullman, WA 99164-6376, (2) Dept. of Food Science & Human Nutrition, Washington State Univ., PO Box 646376, Pullman, WA 99164-6376, (3) Dept. of Animal Science, Washington State Univ., Pullman, WA 99164

Lactic acid and hot water sprays are widely used interventions in beef slaughter establishments to reduce bacterial contamination of carcasses. In this study, the intervention system used by a commercial slaughter plant was evaluated using lactic acid and hot water, or a combination of these two sprays to decontaminate Escherichia coli on the surface of beef carcasses. Also, the effect of chlorous acid on inhibiting E. coli on carcasses was investigated. Beef carcasses were inoculated with E. coli ATCC 25922 and treated with each antimicrobial spray. Using a commercial intervention system, 2 or 4% lactic acid (v/v), hot water (89 ± 1°C ), or combinations were investigated. Using a hand-held spray system, chlorous acid (266 ppm) adjusted to pH 2.5 using acetic acid or citric acid was applied. There were less than 1 log reductions of inoculated E. coli when beef carcasses were treated with 2 or 4% lactic acid for 10.4 s and no significant difference was observed between the results of 2 and 4% lactic acid. Hot water spray for 9.8 s resulted in a 2.1 log reduction of inoculated E. coli. When hot water was followed by with either 2 or 4% lactic acid, there was no difference in the reduction of E. coli between hot water alone or in combination with lactic acid. There were 3.8 and 4.1 log reductions of E. coli observed after treatment with chlorous acid adjusted to pH 2.5 with acetic acid and citric acid, respectively. Chlorous acid was more effective at decontamining E. coli on the surface of beef carcasses than were lactic acid or hot water sprays. Lactic acid spray was the least effective and resulted in less than 1 log reduction.

Session 18D, Food Microbiology: General
2:00 PM - 5:30 PM, Sunday PM Room Hall I-2

2005 IFT Annual Meeting, July 15-20 - New Orleans, Louisiana