TY - JOUR
T1 - Effect of desiccation, starvation, heat, and cold stresses on the thermal resistance of Enterobacter sakazakii in rehydrated infant milk formula
AU - Shaker, R. R.
AU - Osaili, T. M.
AU - Abu Al-Hasan, A. S.
AU - Ayyash, M. M.
AU - Forsythe, S. J.
PY - 2008/9
Y1 - 2008/9
N2 - 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°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°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°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.
AB - 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°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°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°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.
KW - D-value
KW - Enterobacter sakazakii
KW - Infant milk formula
KW - Stresses
KW - Thermal inactivation
KW - Z-value
UR - http://www.scopus.com/inward/record.url?scp=51349120626&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=51349120626&partnerID=8YFLogxK
U2 - 10.1111/j.1750-3841.2008.00880.x
DO - 10.1111/j.1750-3841.2008.00880.x
M3 - Article
C2 - 18803719
AN - SCOPUS:51349120626
SN - 0022-1147
VL - 73
SP - M354-M359
JO - Journal of Food Science
JF - Journal of Food Science
IS - 7
ER -