Influence of Fe2+ -Cation concentration and temperature on the gelation of low methoxyl pectin

Abstract

Here we have investigated the influence of the Iron (Fe 2+) ion concentration, and the temperature on the rheological properties, storage (G') and loss (G'') shear modulus of low methoxyl pectin solutions and gels, in the presence of Fe 2+ ion. Upon lowering the temperature in the presence of Fe 2+ , G'and G''increase immediately followed by a further slow logarithmic increase with time. It was observed that, the storage modulus (G')was increasing with increasing cation concentration initially, further increasing in cation concentration lowering the storage modulus. From the frequency sweep curves, Pectin-Fe 2+ samples exhibiting well structure behaviour at lower Fe 2+ concentration and showing viscous behaviour at higher Fe 2+ concentrations.