Influence of organic acid concentration on survival of Listeria monocytogenes and Escherichia coli 0157:H7 in beef carcass wash water and on model equipment surfaces

• Published in: Food microbiology 2003-12, Vol.20 (6), p.651-660
• Main Authors: Stopforth, J.D., Samelis, J., Sofos, J.N., Kendall, P.A., Smith, G.C.
• Format: Article
• Language: English
• Subjects: Acid adaptation; Biofilm; Biological and medical sciences; Escherichia coli 0157:H7; Food industries; Food microbiology; Fundamental and applied biological sciences. Psychology; Listeria monocytogenes; Meat and meat product industries; Meat decontamination
• ISSN: 0740-0020; 1095-9998
• DOI: 10.1016/S0740-0020(03)00021-2

Acid-adapted cultures of Escherichia coli O157:H7 and Listeria monocytogenes were inoculated in meat decontamination spray-washing runoff fluids in order to evaluate their survival and potential to form biofilms on stainless steel coupons. The cultures (10 7 cfu ml −1) and stainless steel coupons were exposed to mixtures of water and organic acid washings (composites of each of 2% acetic acid or lactic acid washings with water washings from meat decontamination in proportions of 1/9, 1/49, 1/99 [vol/vol]) or to water washings for up to 14 days at 15°C. E. coli O157:H7 formed biofilms and remained detectable (⩾1.3 log cfu cm −2) on stainless steel for up to 4 d in the 1/9 dilution (pH 3.17–3.77) of the organic acid washings, and persisted throughout storage (14 d) in the 1/49 (pH 3.96–4.33) and 1/99 (pH 4.34–6.86) dilution of the organic acid washings. L. monocytogenes populations were unable to form detectable (