The highest elastic modulus was observed for deacylated gellan gum with the addition of CaCl2 and increased slightly with increasing temperature up to 80˚C, which was considered to be a transition temperature,after which it decreased rapidly.
Gellam gum is a bacterial polysaccharide produced by Sphingomonas elodea and has potential industrial applications as a gelling agent alternate to agarose (agar) and carrageenans in the food industry, medicine and biotechnology.
The primary structure of the polysaccharide consists of tetrasaccharide repeating units,
-β-D-Glcp-(1→4)-β-D-GlcpA(1→4)-β-D-Glcp-(1→4)-α-L-Rhap-
The polysaccharide contains Oacetate and L-glycerate groups at C-6 and C-2 of –3)-β-D-Glcp-(1. Under suitable conditions,
the native gellan gum forms weak elastic gels, however, it forms stiff, brittle gels upon deacylation. Physicochemical investigations of deacylated gellan gum have been conducted by many researchers. Chandrasekaranet al. reported that a tertiary structure of deacylated gellan gum consisted of two identical left-handed,three-fold double helices in the solid state, similar to that of agarose molecules.
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