Gelling temperature, gel clarity and texture of gellan gels containing fructose or sucrose

The effects of fructose and sucrose on the gelling temperature, clarity, and texture properties of gellan gels crosslinked with calcium or sodium ions were studied by dynamic rheological, visible light absorption, and compression tests. The gelling temperatures of gellan solutions generally increased due to the addition of sucrose, except when both cation and sucrose concentrations were high. Addition of fructose up to 35%w/v had no effect on the gelling temperatures. Incorporation of fructose and sucrose resulted in a marked increase in the gel clarity. At low cation concentrations, sucrose strengthened the gels; but at high cation concentrations, sucrose weakened the gels. Gels formed by slow cooling in air were more turbid and generally stronger than the gels formed by rapid cooling in water.