Colloidal Particle generally refer to some carbohydrate-based macromolecules, and their chemical structures are mainly composed of a large number of monomers having two or more reactive sites. Most Colloidal Particle are based on different monosaccharides or amino acids as structural units, and then form glycoside or their derivatives by glycosidic or peptide bonds.
Colloidal molecules often contain more hydrophilic groups (such as hydroxyl, carboxyl, amino, etc.), so that the colloid can be fully hydrated or dissolved in water, and further can form a viscous solution or gel, thus Colloidal Particle can exhibit rich functionality and are widely used in food manufacturing.
The colloid polymerization degree, the substituents of the monosaccharide or the amino acid are different depending on the type of the monosaccharide or the amino acid constituting the colloid, the arrangement of the units, the colloid polymerization degree, the substituents of the monosaccharide or the amino acid, and the like, so that the different Colloidal Particle have both properties in common and The characteristics of the. And the dissolution of different Colloidal Particle, viscosity, heat resistance under various physical and chemical conditions, the ability to form jelly, the compatibility of different substances and so there are different degrees of difference. This requires an in-depth study of the relationship between colloidal structure and properties, which can provide a reasonable theoretical basis for the rational application of Colloidal Particle in food, and ultimately get a variety of rich, tastes delicious food.
1, colloidal species
General Colloidal Particle are mainly classified according to their origin. Such as carrageenan, gum tragacanth and gum arabic are plant gum; gelatin, chitosan and chitin are all animal gum; agar, alginic acid and its salt, paralysis gum, carrageenan and alginate are algae gum ; Xanthan gum, available rubber and gellan gum, etc. belong to the microbial glue; methyl cellulose, carboxymethyl cellulose and hydroxyethyl cellulose are chemical modified plastic
2, important features
Food Colloidal Particle are used in many foods because of their versatility, such as Colloidal Particle in some soups, gravy, salad dressings, sauces and toppings are often used as thickeners; in pudding, jelly and jelly Colloidal Particle Gelation in yogurt, ice cream and cream; Colloidal Particle in meat and dairy products can be used as oil substitutes; Colloidal Particle in confectionery and fried foods can be used as a coating agent; in beer and liquor Colloidal Particle can be used as clarifiers; Colloidal Particle in some oils can be used as wrappers; Colloidal Particle in chocolate milk can act as suspending agents; Colloidal Particle in cakes and frozen foods can act to inhibit dehydration; in addition Colloidal Particle can also be used as bioplastics Used in food packaging.
All hydrophilic Colloidal Particle have a thickening effect after hydration. For different types of food Colloidal Particle, the thickening effect is not the same, most of the food colloid in the very low concentration, you can get high viscosity fluid, but there are some Colloidal Particle even at very high concentrations can only be lower Viscosity of the fluid. Viscosity is generally related to the concentration of colloidal solution, pH (pH), temperature, salt ion, shear force. General ionic colloid viscosity by the system of electrolyte, pH effect than non-ionic food glue.
All food Colloidal Particle have a viscosity characteristic and have a thickening function, but only some of the food Colloidal Particle are gelatinous. Generally gelatinous Colloidal Particle are colloidal particles in the solution under certain conditions connected to each other to form a space network structure, and these structures are filled with liquid as a dispersion medium, this special dispersion is the gel The In which the colloid can be used as a continuous phase, the liquid can be regarded as a discontinuous phase; and the gel formed does not have fluidity, and the interior often contains a large amount of liquid. Although many food gels can not form gels when they are present alone, they are mixed together to form a gel, that is, a synergistic effect between the food Colloidal Particle and the synergistic effect of thickening and gelation, such as carrageenan and huai Bean gum, xanthan gum and locust bean gum, tragacanth and sodium alginate.
3) Emulsification stability
Food Colloidal Particle can be stabilized by increasing the viscosity of the emulsion, but the individual molecules of the general food colloid do not simultaneously have the hydrophilic lipophilicity unique to the emulsifier, so they are not real emulsifiers. The main mode of action is through the thickening and increase the viscosity of the water to prevent or weaken the dispersion of the pellet ball migration and polymerization, such as gum arabic and gelatin particles absorbed by the system in the scattered small particles or particles around Forming a coating layer, and the charge evenly distributed to the film particles to repel each other to form a decentralized and stable system; also some hydrophilic Colloidal Particle can play the role of surfactants, reduce the surface tension of the system to achieve the function of emulsion stability.