Polysaccharide gels linear glucans

Curdlan is a bacterial polysaccharide made by Agrobacterium biovar [87,88,89]. It is a linear (1 3)- -glucan (MW 73,000) that forms a triple helix. Curdlan is insoluble in cold water. When aqueous dispersions of curdlan are heated, two types of gels form. First curdlan dissolves. When the solution reaches 55-66 °C, then is cooled, a reversible gel forms. The gel melts when held at about 60 °C. When the thermoreversible gel is heated to a temperature above 80 °C, an irreversible gel forms. Heating to higher temperatures results in stronger irreversible gels. Transition temperatures are a function of concentration. 

By biotransformation of sucrose with amylosucrase a strictly linear polysaccharide a poly(l,4-a-D-glucane), the neoamylose was prepared. The new polymer is fiilly crystalline free of amorphous content and resists enzymatic attack by a-amylase. It forms via cocrystalisation with starch or amylopectine from solution elastically active gels. 

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