Brittney R. Bullard, Haley E. Davis, Rinara C. Kiel, Ifigenia Geornaras, Robert J. Delmore, and Keith E. Belk February, 2016

Transcription

1 Validation of antimicrobial interventions including use of peroxyacetic acid (PAA) in a spray chill system and a head spray cabinet in a commercial beef harvest operation Brittney R. Bullard, Haley E. Davis, Rinara C. Kiel, Ifigenia Geornaras, Robert J. Delmore, and Keith E. Belk February, 2016

2 Introduction Beef carcasses may become contaminated with pathogens during slaughter We need methods to control these pathogens Multiple hurdle technology Peroxyacetic acid (PAA) is approved for use as an antimicrobial in beef processing

3 Objectives To validate the effectiveness of PAA ( ppm) for use in a: spray chill system on beef carcasses head spray cabinet against inoculated populations of non-pathogenic Escherichia coli biotype I (serving as surrogates for pathogenic E. coli and Salmonella spp.) and natural microflora of beef carcasses and heads B896B4F838C3FC54.jpg

4 Experimental Design Carcasses Carcass Study: 40 sides Day 1 n=20 sides Day 2 n=20 sides

5 Experimental Design Heads Head Study: 80 heads Day 1 n=40 heads Day 2 n=40 heads

6 Inoculation and Sampling Inoculum 5-strain mixture of non-pathogenic E. coli biotype I ATCC BAA-1427, ATCC BAA-1428, ATCC BAA-1429, ATCC BAA-1430, ATCC BAA-1431 Known to be surrogates for E. coli O157:H7, STEC and Salmonella

7 Inoculation and Sampling Carcasses and heads were inoculated and sampled within a 10 x 10 cm 2 zone. Heads Right Side = Before Treatment Left Side = After Treatment Four zones were marked on each carcass: A = Uninoculated Before Treatment B = Inoculated Before Treatment C = Uninoculated After Treatment D = Inoculated After Treatment Uninoculated Zones C D B A Inoculated Zones

8 Carcasses Inoculation (6 log CFU/cm 2 ) of zones B&D 10 min attachment time Before treatment zones A&B swabbed After treatment zones C&D swabbed 24 h PAA spray chill (180 to 220 ppm)

9 Heads Inoculation (6 log CFU/cm 2 ) of left and right sides of half of the heads 10 min attachment time After treatment samples obtained from left side Head PAA spray cabinet (180 to 220 ppm) Before treatment samples obtained from right side

10 Microbial Analysis of Samples 15 ml of D/E Neutralizing broth was added to each sponge sample Inoculated samples were plated on Petrifilm Enterobacteriaceae Count Plates. Uninoculated samples were plated on Petrifilm Aerobic Count Plates and Petrifilm Enterobacteriaceae Count Plates.

11 Results Carcass Study Table 1. Least squares mean Enterobacteriaceae plate counts (EB) and aerobic plate counts (APC; log CFU/cm 2 ; ± SE) for inoculated and uninoculated zones of beef carcasses before (untreated control) and after a 24 h peroxyacetic spray chill (180 to 220 ppm). BEFORE AFTER Inoculated (EB) 5.8 ± 0.5 a < 2.4 ± 0.5 b Uninoculated (APC) < -0.2 ± 0.3 a < -0.2 ± 0.3 a Uninoculated (EB) < -0.4 ± 0.1 a < -0.8 ± 0.1 b a,b LSMeans bearing different superscript letters within the same row are different (P < 0.05) LSMeans with a less than symbol (<) indicate at least one sample within the treatment had counts that were below the detection limit (inoculated: 0.1 log CFU/cm 2 and uninoculated: -0.9 log CFU/cm 2 )

12 Results Carcass Study Table 2. Least squares mean Enterobacteriaceae plate counts (EB) and aerobic plate counts (APC; log CFU/cm 2 ; ± SE) for inoculated and uninoculated zones of beef heads before (untreated control) and after a peroxyacetic spray cabinet (180 to 220 ppm). BEFORE AFTER Inoculated (EB) 5.7 ± 0.1 a 4.8 ± 0.1 b Uninoculated (APC) 1.9 ± 0.2 a 1.5 ± 0.2 b Uninoculated (EB) < 0.3 ± 0.1 a < -0.3 ± 0.1 b a,b LSMeans bearing different superscript letters within the same row are different (P < 0.05) LSMeans with a less than symbol (<) indicate at least one sample within the treatment had counts that were below the detection limit (inoculated: 0.1 log CFU/cm 2 and uninoculated: -0.9 log CFU/cm 2 )

13 Conclusions 24 h PAA Spray Chill (180 to 220 ppm) Head PAA Spray Cabinet (180 to 220 ppm) Both interventions would be effective for use in a multiple hurdle system

14 References Keeling, C., S. E. Niebuhr, G. R. Acuff, and J. S. Dickson Evaluation of Escherichia coli biotype I as a surrogate for Escherichia coli O157:H7 for cooking, fermentation, freezing, and refrigerated storage in meat processes. J. Food Prot. 72: King, D.A., L.M. Lucia, A. Castillo, G.R. Acuff, K.B. Harris and J.W. Savell Evaluation of peroxyacetic acid as a post-chilling intervention for control of Escherichia coli O157: H7 and Salmonella typhimurium on beef carcass surfaces. Meat Sci. 69: National Center for Biotechnology Information. Peroxyacetic Acid. PubChem Compound Database; CID=6585. Accessed February 4, Niebuhr, S. E., A. Laury, G. R. Acuff, and J. S. Dickson Evaluation of nonpathogenic surrogate bacteria as process validation indicators for Salmonella enterica for selected antimicrobial treatments, cold storage, and fermentation in meat. J. Food Prot. 71: