Resumo (PT):
High methoxyl pectin (HMP) gelation was investigated by small amplitude oscillatory experimentals. The system studied was 1%HMP + 60% sucrose (citrate buffer, pH 3). Time sweep experiments and mechanical spectra were performed at different temperatures between 5º C and 60° C. The gel time and the shear modules have a complex dependence on temperature, which could be explained by the opposing effects of increasing temperature on both types of interactions that stabilise the HMP gels. The "final" viscoelastic behaviour of HMP gels are also changes with the ageing temperature at which the system has been submitted. Between 15-50°C the behaviour is typical of a true gel, but for lower and higher temperatures, the behaviour changes to that of weak gels. with higher dependence on frequency for the dynamic moduli.
Abstract (EN):
High methoxyl pectin (HMP) gelation was investigated by small amplitude oscillatory experimentals. The system studied was 1%HMP + 60% sucrose (citrate buffer, pH 3). Time sweep experiments and mechanical spectra were performed at different temperatures between 5º C and 60° C. The gel time and the shear modules have a complex dependence on temperature, which could be explained by the opposing effects of increasing temperature on both types of interactions that stabilise the HMP gels. The "final" viscoelastic behaviour of HMP gels are also changes with the ageing temperature at which the system has been submitted. Between 15-50°C the behaviour is typical of a true gel, but for lower and higher temperatures, the behaviour changes to that of weak gels. with higher dependence on frequency for the dynamic moduli.
Idioma:
Português
Tipo (Avaliação Docente):
Científica
Nº de páginas:
5