Suitability of ccRSM as a tool to predict inactivation and its kinetics for Escherichia coli, Staphylococcus aureus and Pseudomonas fluorescens in homogenized milk treated by manothermosonication (MTS)
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- 作者：Oliver Cregenz谩n-Alberti ; Rachel M. Halpin ; Paul Whyte ; James Lyng ; Francesco Noci
- 关键词：Milk ; Ultrasound ; ccRSM ; Escherichia coli ; Staphylococcus aureus ; Pseudomonas fluorescens
- 刊名：Food Control
- 出版年：May, 2014
- 年：2014
- 卷：39
- 期：Complete
- 页码：41-48
- 全文大小：990 K
文摘
The application of ultrasound (US) technology (i.e. sonication) has been used as an alternative to thermal technologies to reduce the microbial population of foods and beverages. This approach can be used on its own or combined with pressure and temperature (i.e. manothermosonication (MTS)). Microbial inactivation kinetics by sonication remains unclear. In the present study, a central composite response surface model (ccRSM) was used in order to study the effects of temperature (20-52聽掳C), acoustic intensity (60-120聽W/cm2) and treatment time (40-240聽s) at a constant pressure (225聽kPa) by MTS processing on microbial inactivation. Reductions of up to c. 1.6聽log聽CFU/ml were achieved for Escherichia coli and Pseudomonas fluorescens. Lower inactivation values were reported for Staphylococcus aureus (1.05聽log聽CFU/ml). These inactivation values were achieved using conditions of 36聽掳C, 90聽W/cm2 and 240聽s. Inactivation of E.聽coli by MTS (R2聽=聽0.90) was described by an exponential curve, whereas inactivation of S.聽aureus and P.聽fluorescens by MTS (R2聽鈮ヂ?.73) were described by a linear trend. The coefficient of determination values were obtained following validation between the theoretical model and the experimental values. Statistical analysis showed that treatment time was the factor with greatest influence on microbial inactivation for all three microorganisms. The present study confirms the suitability of using ccRSM as a tool for investigating and predicting the inactivation of E.聽coli, S.聽aureus and P.聽fluorescens as a function of temperature, acoustic power and treatment time, and may also be useful for predicting inactivation of other microorganisms commonly found in raw milk.