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Optimisation of production and storage stability of the starter bacteria Streptococcus thermophilus and Lactobacillus plantarum
Author(s) -
Selma Maria V,
MacNaughtan William,
Mitchell John,
Waites William
Publication year - 2007
Publication title -
journal of the science of food and agriculture
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.782
H-Index - 142
eISSN - 1097-0010
pISSN - 0022-5142
DOI - 10.1002/jsfa.2745
Subject(s) - streptococcus thermophilus , lactobacillus plantarum , differential scanning calorimetry , starter , food science , lactose , isothermal process , lactobacillus , chemistry , bacterial growth , bacteria , thermodynamics , fermentation , biology , lactic acid , physics , genetics
The growth of Lactobacillus plantarum and Streptococcus thermophilus was modelled by fitting isothermal calorimetric traces to arbitrary mathematical functions. There was a correlation between certain features on the thermal trace and parameters derived from a Baranyi fit to viable count data. In the presence of 75 g L −1 lactose, S. thermophilus showed a slower rate of growth than in the presence of 5 g L −1 lactose when measured by both viable count and heat flow. A simple equation described the variation in glass transition temperature with water activity for all preparations. A master curve fit for all mortality data for S. thermophilus showed the importance of a transition temperature for the survival of freeze‐dried preparations of bacteria. The temperature at which survival began to be impaired was 15–20 °C below the glass transition temperature determined by differential scanning calorimetry. Copyright © 2007 Society of Chemical Industry