초록
<P><B>Simple Summary</B></P><P>Pathogens such as bacteria and molds have been contaminating foods including pet foods over the years. Contaminated pet food, apart from making pet animals sick, can also cause food-borne illnesses in humans as they are often handled by pet owners and children at home. In this study, we evaluated two types of organic acid mixtures which when applied as coating on pet food kibbles, could potentially mitigate pathogenic bacteria and molds during post-processing operations in the pet food industry. Our results indicated that the organic acid mixtures were considerably effective in mitigating the growth of the targeted pathogens in kibbles. These organic acid mixtures also have an additional advantage of being food-safe ingredients that are safe for consumption for the animals, and also provide some gut health benefits for them.</P><P><B>Abstract</B></P><P>Post-processing operations of extruded pet food kibbles involve coating the product with fats and flavorings. These processes increase the risk for cross-contamination with food-borne pathogens such as <I>Salmonella</I> and Shiga toxin-producing <I>Escherichia coli</I> (STEC)<I>,</I> and mycotoxin-producing molds such as <I>Aspergillus</I> spp. after the thermal kill step. In this study, the antimicrobial effects of two types of organic acid mixtures containing 2-hydroxy-4-(methylthio) butanoic acid (HMTBa), Activate DA™ and Activate US WD-MAX™, against <I>Salmonella enterica,</I> STEC and <I>Aspergillus flavus</I> when used as a coating on pet food kibbles were evaluated. Using canola oil and dry dog digest as fat and flavor coatings, the efficacy of Activate DA (HMTBa + fumaric acid + benzoic acid) at 0%, 1% and 2%, and Activate US WD-MAX (HMTBa + lactic acid + phosphoric acid) at 0%, 0.5% and 1% was tested on kibbles inoculated with a cocktail of <I>S. enterica</I> serovars (Enteritidis, Heidelberg and Typhimurium) or Shiga toxin-producing <I>E. coli</I> (STEC) serovars (O121, and O26) at 37 °C for 0, 12, 24, 48, 72 h, 30 and 60 days. Similarly, their efficacy was tested against <I>A. flavus</I> at 25 °C for 0, 3, 7, 14, 21, 28 and 35 days. Activate DA at 2% and Activate US WD-MAX at 1% reduced <I>Salmonella</I> counts by ~3 logs after 12 h and 4–4.6 logs after 24 h. Similarly, STEC counts were reduced by ~2 logs and 3 logs after 12 h and 24 h, respectively. Levels of <I>A. flavus</I> did not vary up to 7 days, and afterwards started to decline by >2 logs in 14 days, and up to 3.8-log reduction in 28 days for Activate DA and Activate US WD-MAX at 2% and 1%, respectively. The results suggest that the use of these organic acid mixtures containing HMTBa during kibble coating may mitigate post-processing enteric pathogen and mold contamination in pet food kibbles, with Activate US WD-MAX being effective at a lower concentration (0.5–1%) compared to Activate DA.</P>