Modelling the lag time and growth rate of Aspergillus section Nigri IOC 4573 in mango nectar as a function of temperature and pH.
OBJECTIVE
To assess the behaviour of Aspergillus section Nigri IOC 4573 in mango nectar as affected by temperature and pH.


RESULTS
A central composite design (2(2)+2*2+3) was used to estimate the influence of temperature (17·2-22·8°C) and pH (3·28-4·7) on A. section Nigri growth (λ, lag time; μ, growth rate). Secondary models (polynomial and Arrhenius-Davey) describing the effects of temperature and pH on λ and μ were constructed. A decrease in temperature from 22·8°C to 17·2°C resulted in an a 16-fold increase in λ. The increase in temperature from 20°C to 22·8°C at pH=4·0 led to a fourfold increase in μ. The polynomial model was the best in fitting the data and the pH (linear), temperature (linear and quadratic terms) significantly influenced λ. For μ, there was a significant influence by the pH (linear), temperature and pH (quadratic terms).


CONCLUSIONS
The storage of mango nectar at <15°C and reduced pH could completely inhibit the growth of A. section Nigri.


CONCLUSIONS
This is the first study to show how storage temperature and seasonal variability (pH) between harvests may affect mould growth in mango nectar.
Silva
A R
AR
Department of Food Science, Faculty of Food Engineering (FEA), University of Campinas (UNICAMP), Campinas, SP - Brazil. marx@fea.unicamp.br
Sant'Ana
A S
AS
Massaguer
P R
PR
D001230:Aspergillus / Q000254:growth & development*; D006863:Hydrogen-Ion Concentration; D031022:Mangifera / Q000382:microbiology*; D008954:Models, Biological; D057048:Plant Nectar; D013696:Temperature
D057048:Plant Nectar