Effect of pH on Inactivation of Escherichia coli K12 by Sonication, Manosonication, Thermosonication, and Manothermosonication
- 4 May 2009
- journal article
- Published by Wiley in Journal of Food Science
- Vol. 74 (4), E191-E198
- https://doi.org/10.1111/j.1750-3841.2009.01130.x
Abstract
The effect of pH on inactivation of Escherichia coli K12 by sonication at 100 kPa/40 °C, manosonication (MS) at 400 kPa/40 °C, thermosonication (TS) at 100 kPa/61 °C, and manothermosonication (MTS) at 400 kPa/61 °C at acoustic energy density of 3 W/mL and 6 W/mL was investigated. Five linear and nonlinear kinetic models were used to examine the inactivation kinetics. At all pH levels, the inactivation rates of E. coli K12 in a buffer by TS and MTS were significantly higher than those by sonication and MS. A 5 log reduction of E. coli K12 population by TS and MTS was achieved in 0.5 and 0.25 min, respectively. With an initial count of 108 CFU/mL, no colonies were detected at pH 3 after a 0.25‐min MTS treatment. The lethal effect of MTS was enhanced at low pH (pHs 3 and 4), whereas at nonlethal temperature of 40 °C, no increased killing was observed. Regardless of pH, the treatment by MTS, TS, and MS exhibited a rapid initial reduction followed by tailing‐off on the inactivation curves. The biphasic linear, log‐logistic, and modified Gompertz kinetic models allowed better fitting of the inactivation data for MTS, TS, and MS treatments than the 1st‐order and Weibull models. The survival counts of sonication‐treated E. coli K12 at all pH levels fitted well to a 1st‐order kinetic model.Keywords
This publication has 33 references indexed in Scilit:
- Physiological Response and Protein Expression under Acid Stress of Escherichia coli O157:H7 TWC01 Isolated from TaiwanJournal of Agricultural and Food Chemistry, 2007
- Use of linear, Weibull, and log-logistic functions to model pressure inactivation of seven foodborne pathogens in milkFood Microbiology, 2007
- Ultrasound pasteurization: The effects of temperature, soluble solids, organic acids and pH on the inactivation of Escherichia coli ATCC 25922Ultrasonics Sonochemistry, 2007
- Quantification of the Effects of Salt Stress and Physiological State on Thermotolerance of Bacillus cereus ATCC 10987 and ATCC 14579Applied and Environmental Microbiology, 2006
- Inactivation of Escherichia coli with Power Ultrasound in Apple CiderJournal of Food Science, 2006
- Acid adaptation and temperature effect on the survival of E. coli O157:H7 in acidic fruit juice and lactic fermented milk productInternational Journal of Food Microbiology, 2001
- Resistance of heat‐shocked cells ofListeria monocytogenesto mano‐sonication and mano‐thermo‐sonicationLetters in Applied Microbiology, 1999
- Influence of acid tolerance responses on survival, growth, and thermal cross-protection of Escherichia coli O157:H7 in acidified media and fruit juicesInternational Journal of Food Microbiology, 1998
- Potential of lactic acid bacteria and novel antimicrobials against Gram-negative bacteriaTrends in Food Science & Technology, 1997
- A REVIEW Tailing of Survival Curves of Bacterial SporesJournal of Applied Bacteriology, 1977