LE3 .A278 2009

2009

Bell, Colin
Ells, Tim

Acadia University

Bachelor of Science

Honours

Biology

Biology

Enterobacter sakazakii has been identified as the causative agent in cases of neonatal enterocolitis, meningitis, and septicaemia following consumption of contaminated infant formula. Post‐pasteurization contamination has been identified as the causative agent leading to contamination (Nazarowec‐White and Farber, 1997); therefore, safe consumer reconstitution practices are vital. In this study, the thermal inactivation kinetics were determined for mild heat treatments in 0.1% peptone water (P.W.) and reconstituted powdered infant formula (PIF) for E. sakazakii strain CHPL 88 at 52, 56, and 60 °C. Cellular inactivation did not follow first order log linear kinetics and was subsequently modelled using the GIna‐FIT add‐in software for Microsoft Excel® (1997‐ 2003). Inactivation parameters were calculated using the Geeraerd et al., (2000) shoulder model. Substantial differences in 4D reduction times, lag periods, and maximum inactivation rates (Kmax values), were observed between mild heat treatments in 0.1% P.W. and reconstituted PIF. Fifty‐nine E. sakazakii isolates were heat treated in 0.1% P.W. at 52 and 60°C in reference to four decimal (4D) reduction times for CHPL 88, results indicated widespread variability in the level of heat tolerance among strains with no apparent relationship pertaining to source of isolate. The results of this study may be used in determining safe heating regimes during preparation of reconstituted PIF in order to avoid risk of infection.

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https://scholar.acadiau.ca/islandora/object/theses:592