Rheological Changes During Gelation of High-Methoxyl Pectin/Fructose Dispersions: Effect of Temperature and Aging

Gels made with 0.5% and 1% pectin in 60% fructose, and a commercial sample exhibited macromolecular solution/weak gel behavior. Cooling the gels from 50–10°C increased storage (G') and loss moduli (G') of the gels. As the rate of cooling (10, 5.7, and 2.5°C/hr) a 1% pectin, 60% fructose, dispersion increased, the elasticity of the formed gel decreased; however, G' was not affected much by rate of cooling. During the first 24 hr, the changes in G'and G' were small. After 14 days storage at ambient temperature, G’values of gels increased substantially, while G' values increased slightly.