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Advisor(s)
Abstract(s)
Sucrose thermal degradation is an important reaction in the food industry. When in concentrated and neutral solutions, pure sucrose presents a lag phase in the reaction. This work aimed at: (i) modelling sucrose thermal degradation autocatalytic behaviour and (ii) studying the concentration and temperature effects on kinetic parameters. Isothermal experiments were conducted at temperatures ranging
from 100 to 180 C, using solutions with varying water content (3.58–30.03 (% w/w)). The logistic and Gompertz sigmoidal equations
were modified and reparameterised, in order to describe degradation behaviour with kinetic parameters with physical meaning (maximum reaction rate, kmax, and lag time, k). In both models these parameters presented an Arrhenius type dependence on temperature. Following a mixed model effect methodology, the concentration dependence was observed on the Arrhenius parameters. This concentration effect was included in the proposed kinetic models, which were able to successfully describe experimental data.
Description
Keywords
Sucrose thermal degradation Concentrated solutions Autocatalytic reactions Arrhenius and mixed model effects
Pedagogical Context
Citation
QUINTAS, M. ; BRANDÃO, T.R.S. ; SILVA, Cristina L.M. - Modelling autocatalytic behaviour of a food model system- sucrose thermal degradation at high concentrations. Journal of food engineering. ISSN 0260-8774. Vol. 78, n.º 2 (2007), p. 537-545
Publisher
Elsevier