INVESTIGADORES
GOMEZ ZAVAGLIA Andrea
artículos
Título:
Effect of Physical Properties on the Stability of Lactobacillus bulgaricus in a Freeze-Dried Galacto-oligosaccharides Matrix
Autor/es:
E. TYMCZYSZYN, N. SOSA, E. GERBINO, A. HUGO, A. GÓMEZ ZAVAGLIA, C. SCHEBOR
Revista:
INTERNATIONAL JOURNAL OF FOOD MICROBIOLOGY
Editorial:
ELSEVIER SCIENCE BV
Referencias:
Lugar: Int J. Food Microbiol. (2012) 155: 217-221 ; Año: 2012 vol. 155 p. 217 - 221
ISSN:
0168-1605
Resumen:
The ability of galacto-oligosaccharides (GOS) to protect Lactobacillus delbrueckii subsp. bulgaricus upon freeze
drying was analyzed on the basis of their capacity to form glassy structures. Glass transition temperatures
(Tg) of a GOS matrix at various relative humidities (RH) were determined by DSC. Survival of L. bulgaricus
in a glassy GOS matrix was investigated after freezing, freeze drying, equilibration at different RHs and storage
at different temperatures. At 32 °C, a drastic viability loss was observed. At 20 °C, the survival was affected
by the water content, having the samples stored at lower RHs, the highest survival percentages. At 4 °C, no
decay in the cells count was observed after 45 days of storage. The correlation between molecular mobility
[as measured by Proton nuclear magnetic resonance (1H NMR)] and loss of viability explained the efficiency
of GOS as cryoprotectants. The preservation of microorganisms was improved at low molecular mobility and
this condition was obtained at low water contents and low storage temperatures. These results are important
in the developing of new functional foods containing pre and probiotics.