Glyceryl Monostearate has many other functions in food besides its typical surface-active effect. The combination of these surface-active effects and special effects in food is the basis for the application of monoglycerides in the processing of flour products. On this basis, monoglycerides can not only improve food quality, prolong food storage period, and improve food sensory properties, but also prevent food spoilage, facilitate food processing and preservation, and contribute to the development of new foods.
1. Surface activity of Glyceryl Monostearate
Glyceryl Monostearate is a nonionic surfactant with an amphiphilic molecular structure. Its lipophilic group is composed of fatty acid, and its hydrophilic group is composed of glycerol. This amphiphilic molecular structure is the premise for the generation of surface activity, and enables glycerides to be easily enriched on the surface of the solution for adsorption, and oriented on the surface and interface, resulting in surface activity and interfacial activity, reducing surface or interfacial tension. . In addition, the monoglycerides are oriented on the gas-liquid or gas-fat interface, which improves the mechanical strength and elasticity of the air bubbles, so that the air bubbles can expand more without breaking.
The commonly used Glyceryl Monostearate has two hydrophilic hydroxyl groups and one lipophilic octadecyl group, so it can be adsorbed on the mutually repelling phases of oil and water, forming a thin molecular layer and reducing the interface between the two phases. Tension, so that the originally immiscible substances can be uniformly mixed to form a uniform dispersion system, which changes the physical state of the raw materials, thereby improving the internal structure of the food and improving the quality.
2. Interaction of Glyceryl Monostearate and Flour Components
Carbohydrates, proteins and lipids play a decisive role in the complex process of producing pasta. The actions of the various flour components are determined by their composition or the products of their interactions. Monoglycerides can interact with flour components in many ways and can correspondingly affect product quality.
1) Interaction of Glyceryl Monostearate with starch
When the starch is gelatinized and swelled by heat, the monoglyceride and water together form a lamellar dispersed phase of liquid crystals and penetrate into the starch granules, interacting with the amylose outside the leached starch granules and the amylose outside the starch granules. The monoglyceride is tightly packed in the amylose helical structure to form a strong complex, that is, the amylose is fixed in the starch granules, and the amylose dissolved in the free water around the starch granules is reduced, and the lipophilicity of Glyceryl Monostearate The base enters the amylose helical structure to form an insoluble complex, which prevents the recrystallization between starch granules and causes aging.
2) Interaction of Glyceryl Monostearate with proteins
There are two water-insoluble proteins in flour, glutenin and gliadin. In the operation process of adding water to flour to form dough, these two proteins absorb water and swell. Glutenin forms a single-chain small molecular substance with strong viscosity and no elasticity; glutenin forms a macromolecular multi-chain substance with good elasticity and no viscosity.
During dough processing, small molecular glutenin is dispersed into macromolecular glutenin to form a special network structure that is both elastic and viscous, namely gluten. After adding monoglyceride, the monoglyceride can interact with gluten protein to form a complex, that is, the hydrophilic group of Glyceryl Monostearate is combined with glutenin, and the lipophilic group is combined with glutenin, so that the mechanical stirring during the process is scattered. The gluten protein molecules are connected to each other, and small molecules become large molecules, which in turn form a strong, tight gluten network. It is precisely because of this good “bridging effect” that the free protein in the dough is significantly reduced, while the bound protein is significantly increased.
3) Interaction of Glyceryl Monostearate with lipids
The α-crystal form of oil is the most unstable and has a very low melting point, while the β-crystal form and the β′-crystal form are both stable and have a higher melting point. processing performance. To keep the oil in the β’-crystal state, crystal modifiers must be added. The stable β’-crystal state can be obtained when monoglycerides are co-crystallized with oils and fats. Grease in β′-crystal state, with high melting point, good plasticity and spreadability. Glyceryl Monostearate can improve the cohesion between fats and the ability to combine with fats to form a crystal network structure, thereby improving the crystal crystallization of fats and improving the stability of oils, which is very beneficial for the production of heavy oil cakes and biscuits. It can prevent the occurrence of oil-water separation of dough or products due to long-term storage, that is, the phenomenon of “going oil”, which improves the storage period and ensures the quality.