Assessing the Efficacy of Sodium Bisulfate and Organic Acid Treatments for Control of Salmonella Typhimurium in Rendered Chicken Fat Applied to Pet Foods.

ABSTRACT

This study was conducted to evaluate the effects of sodium bisulfate (SBS), lactic acid (LA), phosphoric acid (PA), and combinations of organic acids with SBS on Salmonella in rendered chicken fat and in water. The MICs of the antimicrobials individually and in combination were determined. Efficacies of the antimicrobials against Salmonella were tested in both media. The MICs of SBS, LA, and PA were 0.5, 0.5, and 0.25%, respectively. At the given concentrations in the water phase, 0.5% SBS was more effective (P < 0.05; 2.7-log reduction) than LA and PA at 0 h. SBS and LA were more effective (P < 0.05) than PA with >4-log reductions at 2 h and complete kill at 6 h. After 24 h, each of the chemicals completely eliminated the Salmonella. However, because of low recovery in the fat phase, Salmonella was not detected after 12 h and all three chemicals effectively reduced (P < 0.05) Salmonella at 6 h compared with the control. When combinations were used in the water phase, SBS plus butyric acid decreased (P < 0.05) Salmonella by >5.5 log CFU/mL after 12 h. The SBS+LA combinations were effective (P < 0.05) after 2 h. The combinations of SBS+PA resulted in ∼3.5-log reductions in Salmonella (P < 0.05) after 6 h. In the fat phase, except for the SBS+PA combination, Salmonella reduction was not different from that for the positive control. When SBS was combined with organic acids, Salmonella inhibition was achieved at a lower SBS concentration, indicating a possibly synergistic effect of these chemicals. These results suggest that inclusion of SBS or LA at 0.5% individually or a combination of SBS with organic acids could reduce Salmonella in rendered chicken fat contaminated by residual water encountered during storage and transport.