Thickeners generally have the following characteristics:
1. It has a certain solubility in water.
2. It can strongly swell in water and quickly dissolve or gelatinize in a certain temperature range.
3. Aqueous solution has greater viscosity.
4. Gels and films can be formed under certain conditions.
Thickeners stabilize the emulsion by increasing its consistency, but their individual molecules are not simultaneously hydrophilic and lipophilic, so thickeners are not true emulsifiers.
Thickeners all belong to macromolecular polymers, in their macromolecular chain, whether straight chain, branch chain or cross-linked chain, there are some acidic, neutral or basic groups distributed, so that it has a variety of complexing properties.
Thickening agent
Food thickener is one of the most important raw materials in food industry. It mainly plays the role of stabilizing food “form” in food processing. Such as suspension stability, foam stability, emulsion stability and so on. In addition. It can improve the feel of food and
The consistency of color, aroma, taste and water in processed foods.
(1) thickening, dispersion and stabilization
Edible thickeners are water-soluble polymers, soluble in water has a large viscosity. When the viscosity of the system increases, the dispersed phase in the system is not easy to aggregate and agglutinate, so the system is stable. The thickener has surface activity and can be adsorbed on the surface of dispersed phase, making it hydrophilic and easy to disperse in water system. Used in jams, granular foods (such as solid drinks), canned foods, soft drinks and margarine, etc., to give the product a satisfactory consistency.
（2）gelation and coagulation and clarification
Under certain conditions, the polymer solute or colloid particles are connected with each other to form a three-dimensional network structure, while the solvent small molecules are filled in the gap of the network frame, and become a semi-solid system that loses fluidity. This phenomenon is called gelation. Food glue is jelly, custard, jelly, jam, fudge, bionic food and other food gelling agent and excipient.
Thickener is a polymer material, under certain conditions, can be adsorbed on multiple dispersed medium body to condense, so as to achieve the purpose of purification. Such as carrageenan can be clarified in fruit juice food.
（3）Water retention effect
Thickener is hydrophilic polymer, itself has a strong water absorption. Add it to the food, can make the food to maintain a certain moisture content, that is, improve the yield, and increase the taste. Such as in meat products, bread, cakes and other foods, can play a role in tissue improvement.
（4）Control crystallization
Thickeners can give foods a high viscosity, which makes the system less likely to crystallize or make crystals fine. Ice crystals can be prevented from growing in ice cream. In the candy to prevent sugar crystallization, that is, to prevent “sand back”.
（5）film forming and preservation effect
Thickener can make the food surface to form a protective film, protect food from oxygen, microbial action. Combined with edible surfactants, it can be used for the preservation of fruits and vegetables. Such as sodium alginate, CMC can form a film.
（6）Other functions
a. Foaming effect
In cake, bread, etc. can be used as foaming agent, such as gelatin, foaming ability is 6 times of eggs.
b. It has a masking effect on the bad flavor
Can eliminate the odor in food, such as cyclodextrin, adding 2% to 5% in soy milk can significantly reduce the smell of beans.
c. Role of dietary fiber
Polysaccharide thickener is not digested and absorbed by human body, and has the effect of dietary fiber.
