The prominent role of thickeners in food
The prominent role of thickeners in food is mainly as follows:
(1) Thickening, dispersion and stabilization
Edible thickeners are all hydrophilic polymer substances. It has a great viscosity when dissolved in water, which makes the system feel thick. After the viscosity increases, the dispersed phase in the system is not easy to aggregate and agglomerate, so the dispersed system can be stabilized. Most thickeners have the function of surfactants and can be adsorbed on the surface of the dispersed phase to make them hydrophilic and easy to disperse in water systems. The molecular weight distribution and concentration of the thickener, the temperature of the solution, and the shear rate of the pH value machine will all affect the viscosity of the solution.
Some thickeners, such as gelatin, agar and other solutions, are viscous fluids under warm conditions. When the temperature decreases, the solution molecules connect into a network structure, and the solvent and other dispersion media are all contained in the network structure. The system formed a semi-solid with no fluidity, that is, a gel. Many food processing uses this characteristic of thickeners, such as jelly and panna cotta. Some ionic water-soluble polymer thickeners, such as sodium alginate, can form a gel in the presence of high-valent ions, regardless of temperature. This brings convenience and help to the processing of many specialty foods.
(3) Cohesion and clarification
Most thickeners are macromolecular materials. Under certain conditions, multiple dispersion media can be adsorbed at the same time to make them aggregate and separate to achieve the purpose of purification or purification.
(4) Water retention
Water-holding thickeners are all hydrophilic polymers, which have strong water absorption. After adding them to food, they can maintain a certain amount of water in the food, so that the product maintains a good taste. The hydrophilic function of the thickener can improve the quality of meat products and noodle products. For example, in noodles, thickeners can improve the water absorption of the dough. When preparing the dough, the thickener can accelerate the penetration of water into protein molecules and starch particles, which is beneficial to the flour mixing process. The thickener can absorb dozens of times or even hundreds of times the amount of water, and has water retention. This feature can improve the water absorption of the dough and increase the weight of the product.
(5) Controlling crystallization
The use of thickeners can give foods a higher viscosity, so that many supersaturated solutions or systems do not appear to crystallize or make the crystals refined. For example, it can increase the expansion degree, reduce the possibility of ice crystal precipitation, and make the product taste fine; it can control the re-sanding phenomenon of syrup products, and inhibit the appearance of ice crystals in ice cream food or the miniaturization of ice crystals generated during processing. , And contains a large number of tiny bubbles, so that the structure is fine and uniform, the taste is smooth, and the appearance is neat.
(6) Film formation and preservation
Edible thickeners can form a very smooth protective film on the surface of the food to protect the food from oxygen and microorganisms. Used together with food surfactants, it can be used to keep fruits and vegetables fresh, and has a polishing effect. It can also prevent the quality of frozen food and solid powder food from absorbing moisture on the surface.
(7) Foaming and stabilizing foam
The thickener can foam to form a network structure. Its solution is like soap bubbles when it is stirred. It can contain a large amount of gas and liquid bubbles, increasing the surface viscosity of processed foods and making the food stable. When cakes, breads, ice creams, etc. use staghorn gum, locust bean gum, sodium alginate, gelatin, etc. as foaming agents, thickeners can increase foam volume and foam stability.
The purpose of using locust bean gum and carrageenan in sausages is to make the product an agglomerate, the tissue structure is stable and lubricated after homogenization, and the strong water retention of the glue is used to prevent the sausage from losing weight during storage. Gum Arabic can be used as a binding agent for tablets and granular products, used in the granulation of powdered food, the granulation of food flavors and other applications. (9) For the production of health care and low-calorie food
Many thickeners are basically natural colloidal macromolecular substances. It is hardly digested in the human body, but excreted through metabolic processes. Therefore, after replacing part of syrup and protein with thickeners in food, it is easy to reduce the calorific value of the food. This method has been applied to processed foods such as jam, fruit puree, condiments, snacks, biscuits, pudding, etc., and continues to develop in a wider range.
(10) Masking and slow-release effects
Some thickeners can absorb and mask the bad smell of certain raw materials to achieve the effect of deodorization and deodorization, such as the use of cyclodextrin for deodorization, but for some fast-volatile aromas and non Stable nutrients have a slow-release effect.
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