CARB 66 |
| Carrageenans are linear sulfated galactans obtained from red seaweeds (Rhodophyceae) that are commonly used as thickeners in frozen dairy products. These polysaccharides may contain up to 1,000 galactose residues and as a result many structures are possible. The structures are usually defined as 3 main types; kappa, iota and lambda with different types exhibiting different gelling properties. For example, kappa carrageenans produce rigid gels in the presence of potassium ions while gels made with iota carrageenans are weaker, and lambda carrageenans do not gel in water. The present work is an investigation of gelation behavior of alpha-carrageenans. A comprehensive description of macromolecular structure includes molecular shape as well as coil density and flexibility. In our study hydrodynamic information (diffusion coefficient, D and hydrodynamic radius, Rh) are obtained with asymmetric field flow fractionation while simultaneous dynamic multiangle light scattering measures the radius of gyration, Rg and molar mass. The mean coil density is them calculated as Rg/Rh and the coil to helix transition as well as helix aggregation is monitored under different solution conditions. Data for alpha-carrageenan in various salt solutions will be presented and compared to main carrageenan types. |
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General Posters
8:00 PM-10:00 PM, Tuesday, 12 September 2006 Moscone Center -- Hall D, Poster
Sci-Mix
Division of Carbohydrate Chemistry |