Emulsifiers are a large type of substances, although they all have hydrophilic groups and lipophilic groups, but because of the different types and amounts of hydrophilic groups and lipophilic groups contained in the emulsifier, the final emulsifier Characteristics and functions are also different, and sometimes their effects are even reversed. For example, some emulsifiers act as emulsification and stabilization, while others are demulsification and defoaming. At the same time, the variety of foods is also very diverse and of various natures. To this end, we must properly select and use emulsifiers according to the needs of specific products. Moreover, due to the synergistic effect of the mixed emulsifier, when two or more emulsifiers are used at the same time, the effect is better than when using a simple one. At present, both domestic and foreign companies are actively developing and popularizing the composite emulsifier. . Commonly used methods of emulsifier include: high and low HLB values, similar molecular structure, ionic complementation and hydrophilic group conformation complementation.
The HLB value has an effective reference value for the design of composite emulsifier formulations. When an emulsifier is added to the water-oil system, it adsorbs at the interface between the two substances to form an interface film. The interface film has a certain strength and protects the dispersed phase droplets. When the high and low HLB emulsifiers are used in combination, the "composite" is adsorbed at the interface, and the orientation is tight, and the strength is high, so that the coalescence is well prevented and the stability of the emulsification effect is improved.
When the emulsifiers with similar molecular structure are mixed, the synergistic effect is obvious, especially when one emulsifier is another emulsifier derivative, the combination of the two emulsifiers can often achieve satisfactory results. .
The emulsifier is classified into an anion, a zwitterion, and a nonionic type depending on the performance of the hydrophilic group in water. Phospholipids are the only identified and approved amphoteric emulsifiers in food additives. In general, nonionic emulsifiers have a strong emulsifying ability and are a good class of emulsifiers. In the production practice, ion-type emulsifiers still have their unique advantages. Mixing an ionic emulsifier with a nonionic emulsifier is better than using only a nonionic emulsifier, and the emulsification activity and surface activity are stabilized for a long period of time. The lipophilic group of the food emulsifier generally refers to a fatty acid group or a fatty alcohol group, and the difference mainly manifests in the length change or saturation of the hydrocarbon chain, and the structural change of the hydrophilic group of the emulsifier is far more than that of the lipophilic group. The group is closely related to the difference in the properties of the emulsifier.
From the viewpoint of conformation, the structure of the hydrophilic group of the food emulsifier can be divided into two major categories, linear and cyclic. The conformational complementation of a hydrophilic group means that an emulsifier having a different hydrophilic group conformation is used in combination in designing a composite emulsifier to produce a complementary advantage, for example, a hydrophilic group of a monoglyceride is linear, and a sucrose fatty acid ester The hydrophilic group is cyclic, and a good effect can be obtained by mixing the two emulsifiers.
At present, we have the followed compoud food emulsifiers: cake gel emulsifiers, bread emulsifiers, beverage emulsifiers and so on.