Abstract:

The effects of ratio of gellan to carboxyl methyl cellulose (CMC), ion type, and ion concentration on the textural
properties, water-holding capacity (WHC), and clarity of gellan-CMC mixed gels were examined using instrumental texture
profile analysis (TPA), centrifugation and spectrophotometry. Hardness of the mixed gels decreased as the proportion of
gellan decreased, and increased with increasing calcium or sodium ions until ion concentration reached a critical level.
Thereafter, further increases in calcium or sodium resulted in a reduction of hardness. Gel hardness was achieved at a much
higher level with sodium ionthan with calcium ion. In general, the addition of ions caused gels to be less cohesive and
springy. Decreasing gellan to CMC ratio caused an increase in gel clarity. The results of this study suggested a weak positive
interaction between gellan and CMC when no ion was added, whereas gellan formed a continuous network and CMC
discontinuous phase at higher ion levels.

Key words: gellan, carboxyl methyl cellulose, texture profile analysis, water holding capacity, clarity