Determination of thermobacteriological parameters and size of Bacillus stearothermophilus ATCC 7953 spores
Data(s) |
01/12/2010
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Resumo |
In order to determine thermobacteriological parameters for B. stearothermophilus spores, they were diluted in a saline solution medium and in ground corn-soybean mix, distributed in TDT tube, and submitted to heat for a specific period of time. The D value (time to reduce 1 log cycle of microbial count under a certain temperature) and z value (variation of temperature to cause 10-fold change in D value) were estimated. To estimate their dimensions, the spores were visualized by using a scanning electron microscope. D121.1 ºC and z values for these spores, as determined in the saline solution, were 8.8 minutes and 12.8 ºC, respectively. D121,1 ºC and z values determined in the corn-soy mix were 14.2 minutes and 23.7 ºC, respectively. The micrographs indicated that the spores have homogeneous shape and size, with length and diameter of 2 and 1 µm, respectively. These results confirm that the spore is highly thermal-resistant, and it is a good biological indicator to evaluate the extrusion process as a feed sterilizer. |
Formato |
text/html |
Identificador |
http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0101-20612010000400032 |
Idioma(s) |
en |
Publicador |
Sociedade Brasileira de Ciência e Tecnologia de Alimentos |
Fonte |
Food Science and Technology (Campinas) v.30 n.4 2010 |
Palavras-Chave | #thermobacteriology #feed #D value #z value #spore size |
Tipo |
journal article |