Affiliation:
1. Department of Poultry Science, Auburn University, Alabama 36849-5416.
Abstract
The effect of pH reduction with acetic (pH 5.2), citric (pH 4.0), lactic (pH 4.7), malic (pH 4.0), mandelic (pH 5.0), or tartaric (pH 4.1) acid on growth and survival of Escherichia coli O157:H7 in tryptic soy broth with 0.6% yeast extract held at 25, 10, or 4 degrees C for 56 days was determined. Triplicate flasks were prepared for each acid treatment at each temperature. At 25 degrees C, populations increased 2 to 4 log10 CFU/ml in all treatments except that with mandelic acid, whereas no growth occurred at 10 or 4 degrees C in any treatments except the control. However, at all sampling times, higher (P < 0.05) populations were recovered from treatments held at 4 degrees C than from those held at 10 degrees C. At 10 degrees C, E. coli O157:H7 was inactivated at higher rates in citric, malic, and mandelic acid treatments than in the other treatments. At the pH values tested, the presence of the organic acids enhanced survival of the pathogen at 4 degrees C compared with the unacidified control. E. coli O157:H7 has the ability to survive in acidic conditions (pH, > or = 4.0) for up to 56 days, but survival is affected by type of acidulant and temperature.
Publisher
American Society for Microbiology
Subject
Ecology,Applied Microbiology and Biotechnology,Food Science,Biotechnology
Reference17 articles.
1. Survival and growth of Escherichia coli O157:H7 in ground roasted beef as affected by pH, acidulants, and temperature;Abdul-Raouf U. M.;Appl. Environ. Microbiol.,1993
2. Behavior of hemorrhagic Escherichia coli O157:H7 during the manufacture of cottage cheese;Arocha M. M.;J. Food Prot.,1992
3. Banwart G. J. 1979. Basic food microbiology. AVI Publishing Co. Inc. Westport Conn.
4. Barrow G. M. 1981. Physical chemistry for the life sciences. McGraw-Hill Book Co. Inc. New York.
5. Ineffectiveness of hot acid sprays to decontaminate Escherichia coli O157:H7 on beef;Brackett R. E.;J. Food Prot.,1994
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