Efficacy of antimicrobials using an innovative, new electrostatic application system on Salmonella-inoculated poultry parts
Date
2016
Authors
Davis, Haley E., author
Belk, Keith E., advisor
Delmore, Robert J., committee member
Martin, Jennifer N., committee member
Morley, Paul S., committee member
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Volume Title
Abstract
Two studies were conducted to evaluate efficacy of peroxyacetic acid (PAA) as an antimicrobial intervention treatment when applied electrostatically, in reducing inoculated populations of Salmonella serovars on chicken wings. The other objectives of these studies were: to determine critical operating parameters for reducing Salmonella serovars on poultry parts; to evaluate use of static electricity to maximize coverage of antimicrobial solutions applied electrostatically to poultry part surface areas while limiting volume to minimize weight gain; to evaluate use of vacuum to enhance absorption of antimicrobial spray into pores of poultry parts; and to determine optimal rotation speed of the Birko prototype application unit’s containment drum to expose all poultry part surfaces during antimicrobial solution application. Two different electrostatic spray systems (ES1 and ES2) were evaluated in two separate studies. For both studies, chicken wings were inoculated with nalidixic acid- and novobiocin-resistant Salmonella (5-strain mixture; 5-6 log CFU/ml of chicken wing rinse solution) sourced from poultry. Inoculated wings were either left untreated (control) or were treated with water or PAA. In study 1, water and PAA (at a wt/wt concentration of 2000 ppm) were applied (30 s) with one of four application methods: (i) electrostatic spray (ES1), (ii) vacuum, (iii) ES1 + vacuum, or (iv) immersion. Chicken wings were then placed into Whirl-Pak bags containing Dey/Engley (D/E) neutralizing broth and sample rinsates were serially diluted and surface-plated on both tryptic soy agar and tryptic soy agar supplemented with nalidixic acid (20 µg/ml) and novobiocin (25 µg/ml). Overall, least squares means for log10 Salmonella counts differed (P < 0.05) between all treated wings vs. the control. When PAA was applied, electrostatic spray was most effective (P < 0.05) at reducing Salmonella populations. In study 2, treatment solutions of water and two concentrations of PAA (2000 ppm and 4000 ppm) were evaluated. These were applied (30 s) using two differing application methods [a Birko prototype application system (ES2) and immersion]. Sampling methods were the same as those used in study 1, with the exception that analysis of efficacy occurred at both 0 and 24 h. Untreated and treated chicken wings were placed in Whirl-Pak bags and held at 4°C for 24 h before sampling. For study 2, mean bacterial counts for all treatments differed (P < 0.05) from the control and there was a treatment and sampling time interaction. For both water and PAA, the immersion treatment was most effective (P < 0.05) at reducing Salmonella populations after 24 h storage. Both electrostatic spray systems (ES1 and ES2) reduced (P < 0.05) bacterial populations of Salmonella, validating electrostatic application as a potential antimicrobial intervention method for chilled poultry parts.
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Subject
electrostatics
Salmonella
peroxyacetic acid (PAA)
antimicrobials