Carrageenan viscosity

Carrageenan has long been considered to be a simple polymer of D-galacto-4-sulfate joined at carbons 1 and 3. While this unit is part of the main structural feature, recent work has disclosed additional fine points. Thus, carrageenan is known to be a mixture of components of varying viscosities and varying sensitivities to potassium. 

The addition of hydrocolloids (e.g. carrageenans, pectins or car-boxymethyl cellulose) as thickening agents will greatly increase the apparent viscosity of the product. The production of extracellular polysaccharides by certain bacteria will also increase the viscosity of milk products. 

Mainly the gel-forming properties of x-carrageenan are used for pharmaceutical purposes. Due to the high viscosity of the. -carrageenan, it is employed as an emulsifying and stabilizing agent. 

Carrageenans, alginates, polysaccharides, carboxy methyl cellulose etc. Provide mouthfeel, shelf-life stability, viscosity... 

In addition to their role in primary stabilization related to viscosity increase, some hydrocolloids (particularly carrageenan) are traditionally used as secondary stabilizers. Many of the primary stabilizing hydrocolloids, including locust bean gum and carboxy methyl cellulose induce precipitation of the milk proteins in the mix. This phenomenon in ice cream mix is known as wheying-off, and may be due to direct protein-polysaccharide binding and/or protein-polysaccharide incompatibility in the water phase40. The latter phenomenon may be due to decreased solvent quality due to the competition between protein and polysaccharide for solubilisation. 

Class A. Water-soluble synthetic and natural organic polymers, which increase the viscosity of the mixing water. They include cellulose ethers, pregelatinized starches, polyethylene oxides, alginates, carrageenans, polyacrylamide, carboxyvinyl polymers and polyvinyl alcohol. 

In the present work we have studied the dynamics of formation and structure of the air-water interface in the presence of (3-lg - - PS at 20°C and at pH 7 in a drop tensiometer. As PS with interfacial activity we have used propylene glycol alginates (PGA). To evaluate the effect of the degree of PGA esterification and viscosity, different commercial samples were studied. Xanthan gum (X) and X-carrageenan (X-c) were studied as nonsurface active polysaccharides. 

Figure 2 Apparent viscosity as a function of time (a) and as a function of temperature (b) during cooling K-carrageenan/soy protein mixed systems...

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