Based on the special properties of carrageenan, carrageenan is commonly used in the food industry as a thickener, gelling agent, suspending agent, emulsifier and stabilizer. The viscosity of the carrageenan solution increases with increasing pH, and is substantially stable when it is near neutral, and then decreases. The acidity is enhanced, the H+ is increased, the carrageenan molecule is dissociated and neutralized, and the electrostatic attraction between the semi-esterified sulfates is weakened. Alkaline enhanced, OH- and negatively charged carrageenan repelled to reduce the entanglement of molecular drops, so the viscosity of the solution decreased under strong acid and strong alkaline conditions. The viscosity of the solution will decrease when a certain cation is present in the solution. This is because the cation can reduce the electrostatic attraction between the half esterified sulfates.
After the carrageenan can adsorb the protein molecules in the protein solution, the protein solution is suspended and stabilized. The practical application is a stabilizer for dairy beverages and an ice cream emulsion stabilizer to stabilize the thickened milk protein solution. The protein in the solution aggregates to form protein micelles. The carrageenan is free in solution and reacts with the naked amino acid fragments of the protein micelles. Condensation, sedimentation, suspension and gelation occur respectively according to the concentration and pH; The proteins in the solid state are subjected to salt extraction (picking, rolling) and heat treatment, and proteins react with each other to form a protein network structure, and carrageenan can strengthen the structure by interaction with proteins.
The thickening of carrageenan is weak, and it is also confused with protein reactivity in practical applications, so it is one property that involves the least practical application. In practical applications, the weak gel carrageenan thickening is generally used for ice cream and milk beverages, combined with the weak gel network structure produced by the carrageenan-protein system, plus the action of calcium salt, can give the material a certain consistency.