Article

Effect of desiccation, starvation, heat, and cold stresses on the thermal resistance of Enterobacter sakazakii in rehydrated infant milk formula.

Dept of Nutrition and Food Technology, Jordan Univ of Science and Technology, Irbid, Jordan.
Journal of Food Science (impact factor: 1.66). 10/2008; 73(7):M354-9. DOI:10.1111/j.1750-3841.2008.00880.x pp.M354-9
Source: PubMed

ABSTRACT Enterobacter sakazakii is an opportunistic foodborne pathogen that has been isolated from powdered infant milk formula. This study determined the effect of desiccation, starvation, heat and cold stresses on the thermal inactivation of E. sakazakii in rehydrated infant milk formula (RIMF). Stressed cells were mixed with RIMF at 52, 54, 56, and 58 degrees C for various time periods. The D- and z-values were determined by using linear regression analysis. D-values for unstressed E. sakazakii at 52, 54, 56, and 58 degrees C were 15.33, 4.53, 2, and 0.53 min, respectively. Desiccation and heat stresses, but not starvation or cold stress, caused significant (P < 0.05) reduction in D-values. The z-values of desiccated, starved, heat stressed, and cold stressed E. sakazakii were not significantly different from unstressed cells (4.22 degrees C). Thermal resistance of E. sakazakii in RIMF is affected by the environmental stresses; that is, desiccation and heat stresses that may surround the bacterium prior to the contamination of infant formula. The results of this study may be of use to regulatory agencies, infant milk producers, and infant caregivers to design heating processes to eliminate E. sakazakii that may be present in infant milk formula.

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    Article: Thermal inactivation of acid, cold, heat, starvation, and desiccation stress-adapted Escherichia coli O157:H7 in moisture-enhanced nonintact beef.
    Cangliang Shen, Ifigenia Geornaras, Keith E Belk, Gary C Smith, John N Sofos
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    Journal of food protection 04/2011; 74(4):531-8. · 1.94 Impact Factor
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Keywords

58 degrees C
 
cold stress
 
cold stresses
 
D-values
 
design heating processes
 
E. sakazakii
 
Enterobacter sakazakii
 
environmental stresses
 
heat stresses
 
infant caregivers
 
infant milk producers
 
linear regression analysis
 
opportunistic foodborne pathogen
 
powdered infant milk formula
 
regulatory agencies
 
rehydrated infant milk formula
 
Stressed cells
 
unstressed cells
 
unstressed E. sakazakii
 
various time periods