CIDCA   05380
CENTRO DE INVESTIGACION Y DESARROLLO EN CRIOTECNOLOGIA DE ALIMENTOS
Unidad Ejecutora - UE
artículos
Título:
Modelling the effect of temperature and water activity on the growth
Autor/es:
GALATI S., GIANNUZZI L., GINER S. A.
Revista:
JOURNAL OF STORED PRODUCTS RESEARCH
Editorial:
PERGAMON-ELSEVIER SCIENCE LTD
Referencias:
Año: 2011 vol. 47 p. 1 - 7
ISSN:
0022-474X
Resumen:
A full factorially designed experiment including storage temperature (10, 20, 30 and 37 C) and water
activity (0.88, 0.92 and 0.96) was undertaken to study the growth of Aspergillus parasiticus in maize
samples. Kinetic parameters such as specific growth rate (m), lag phase duration and maximum logarithmic
increase were determined by fitting the Modified Gompertz equation to the viable mould count
data (N in CFU/g) as a function of time collected in twelve experiments. The average coefficient of
determination (R2) was 0.987, being the mean standard deviation of the estimate of 0.216 in units of
log10N. In the practical range of 10e30 C, the relationship of the three kinetic parameters with
temperature was described by second order polynomial expressions, whose parameters, in turn,
depended on water activity. The combined or full model i.e., the Modified Gompertz model with its
parameters expressed as a function of temperature and water activity, was able to predict log10N with an
average percentage error of 4.3, so agreement with the experimental data was highly satisfactory.
In a simulation exercise, the full model was able to predict the viable mould count, given an initial
value and grain temperature and water activity histories, with promising results for maize storage.