Journal of Food Technology
ISSN: Online 1993-6036ISSN: Print 1684-8462
Abstract
The thermodynamics of heat destruction of Listeria monocytogenes in soymilk of varying initial pH (6.0-6.8) and sugar contents (0.5-10% w/v) were studied using kinetic parameters generated via the classical thermobacteriology assumption of a log-linear relationship between Listeria monocytogenes survivors and heating time (0.5-30 min at 50-65°C). The activation enthalpy (ΔH+), entropy (ΔS+), Energy (Ea) and frequency factor (k0) for the heat inactivation ranged, respectively, from about 275-302, 612-705 J/mol deg., 277-305 kJ/mol and 2.9x1043-2.0x1048 min-1 increasing with increases in initial sugar contents and acidity of soymilk. A kinetic compensation effect was observed for both ΔS+/ΔH+ and ln k0/Ea relationships with isokinetic temperature of 32.16x0.13°C and isokinetic destruction rate constant of 9.21x10-5 min-1 for the microbe in soymilk.
How to cite this article:
M.A. Igyor, C.C. Ariahu and C.U. Inyang. Thermodynamics of Heat Inactivation of Listeria monocytogenes in Soymilk of Varying Initial pH and Sugar Values.
DOI: https://doi.org/10.36478/jftech.2012.17.23
URL: https://www.makhillpublications.co/view-article/1684-8462/jftech.2012.17.23