P1-209 Effectiveness of Individual and Combined Antimicrobial Spray Interventions Commonly Used on Chilled Beef Subprimals

Monday, July 10, 2017
Exhibit Hall (Tampa Convention Center)
Jennifer Acuff , Kansas State University , Manhattan , KS
Matthew Krug , Kansas State University , Manhattan , KS
Daniel Vega , Kansas State University , Manhattan , KS
Nicholas Sevart , Kansas State University , Manhattan , KS
Sarah Jones , Kansas State University , Manhattan , KS
Amanda Wilder , Kansas State University , Manhattan , KS
Keyla Lopez , Kansas State University , Manhattan , KS
Minto Michael , Kansas State University , Manhattan , KS
Christopher Vahl , Kansas State University, Department of Statistics , Manhattan , KS
Gary Acuff , Texas A&M University , College Station , TX
Harshavardhan Thippareddi , University of Georgia , Athens , GA
Randall Phebus , Kansas State University , Manhattan , KS
Introduction: Beef processors use interventions throughout the slaughter and fabrication process to reduce Shiga toxin-producing Escherichia coli (STEC) contamination risks. Certain approved antimicrobials are marketed for spraying chilled subprimals; however, validation of these treatments using commercial-scale equipment and foodborne pathogens is lacking.

Purpose: This study evaluated the efficacy of three common antimicrobial sprays, individually and combined, against a rifampicin-resistant STEC cocktail (O26, O45, O103, O111, O121, O145, and O157:H7).

Methods: For individual antimicrobial treatments, beef subprimals (n=16) were mist-inoculated with the cocktail (ca. 5 log CFU/cm2), followed by spray-treatment with 200 ppm peracetic acid (PAA), 2% Centron™ (sulfuric acid, sodium sulfate anhydrous and water mixture; CEN), 4.5% lactic acid (LA), or water (W). For combined treatments, inoculated subprimals (n=4) were first treated with PAA, LA, CEN, or W; vacuum packaged; and stored for 72 hours at 4°C. Each subprimal was then divided (n=16) and treated with each of the four antimicrobials as a second treatment. The first study was designed as randomized generalized block, and the second study was designed as a split plot. After each treatment phase, microbial analyses were conducted in duplicate to determine STEC reductions.

Results: For individual antimicrobial treatments, LA and PAA provided greater (P≤0.05) STEC reductions (0.5 and 0.6 log CFU/cm2, respectively) compared to water (0.1 log CFU/cm2), but the CEN reduction (0.2 log CFU/cm2) was similar to water. For combined treatments, reductions ranged from 0.5 log CFU/cm2 to 1.5 log CFU/cm2; the greatest reduction observed when subprimals were treated with LA, vacuum packaging, and another LA application.

Significance: These studies indicate that the individual antimicrobial treatments evaluated are marginally effective for reducing STEC population on chilled beef subprimals during fabrication. Their efficacy may be improved by combining treatments when the beef is stored under vacuum packaged conditions and retreated upon bag opening, as typical of mechanical tenderization operations.