Open AccessFast‐responding thermal‐death‐time tubes for the determination of thermal bacteria inactivation
Author(s) -
Büchner Christin,
Thomas Susann,
Jaros Doris,
Rohm Harald
Publication year - 2012
Publication title -
engineering in life sciences
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.547
H-Index - 57
eISSN - 1618-2863
pISSN - 1618-0240
DOI - 10.1002/elsc.201100041
Subject(s) - enterobacter cloacae , sterilization (economics) , kinetics , chemistry , serratia , volume (thermodynamics) , bacteria , analytical chemistry (journal) , microbiology and biotechnology , chromatography , escherichia coli , enterobacteriaceae , thermodynamics , biology , biochemistry , pseudomonas , physics , genetics , quantum mechanics , monetary economics , economics , foreign exchange market , gene , foreign exchange
The knowledge of thermal inactivation kinetics, usually expressed in terms of D ‐ and z ‐values, is of crucial importance for the design of sanitation and sterilization processes. In this study, we designed a simple, fast‐responding, and mechanically stable aluminum tube for inactivation measurements and compared these experiments with the successive‐sampling method at different temperatures. Up to 65°C, we determined a come‐up time of approximately 15 s for the tubes, which is lower than the corresponding values of other devices, presumably because of lower wall thickness, material properties, and a higher surface to volume ratio. D ‐values of Escherichia coli calculated from tube inactivation experiments by first‐order kinetics were 370 s (56°C), 126 s (58°C), 53.2 s (60°C), 33.8 s (62°C), and 3.22 s (65°C), and the corresponding values determined with the successive‐sampling flask method were insignificantly different (417, 138, 48.6, and 29.1 s for 56, 58, 60, and 62°C, respectively). These data as well as those measured for Enterobacter cloacae , Pseudomonas putida , Serratia odorifera , and Yersinia rhodei were in close accordance with literature values.