Mayonnaise and salad dressing are commonly used condiments in Western cuisine. They are a kind of seasoning sauce in semi-solid form. They are made from vegetable oil, eggs, salt, sugar, spices, vinegar, emulsifiers and thickeners. Mayonnaise is made using a shear homogenizer. The difference between the two is determined by the content of fat and egg yolk: mayonnaise: 75% fat and more than 6% egg yolk; salad dressing: less than 50% fat and more than 315% egg yolk; the water content in general mayonnaise is only 10%-20%, and the water content in salad dressing is 15%-35%. Some countries stipulate that mayonnaise cannot use emulsifier stabilizers other than eggs. If used, the product can only be called salad dressing.

Use High Shear Emulsifier to make mayonnaise. The substance that plays an emulsifying role in the mayonnaise is lecithin. It surrounds the oil droplets with a spatially complete protective film. The emulsifier makes the expansion film elastic and deformable until it is not broken. Thus, the water-in-oil emulsion system is very stable. In addition to using egg yolk as an emulsifier, citric acid monoglyceride and diglyceride, lactic acid monoglyceride and diglyceride are used in combination with lecithin. The shear homogenizer can make the fat finely distributed and improve the viscosity of mayonnaise products. Excessive use of emulsifiers or wrong types will affect the consistency and taste of the product. In order to make the product have an excellent taste, the complex synergistic effect of modified starch, water-soluble colloids, emulsifying substances and emulsifiers is particularly important. The selected emulsifiers and thickeners must be acid-resistant. Emulsifiers cannot completely replace egg yolks. The amount is about 0.15% of the total amount of raw materials.

The process of using a shear homogenizer to produce mayonnaise and salad dressing can adopt an alternating method, an intermittent method or a continuous method to mix and emulsify the two phases to form a water-in-oil emulsion. When using the alternating method, the emulsifier is first dispersed in a part of the water, and then a small part of the oil and the remaining part of the water and vinegar are added alternately. The obtained primary emulsion is subjected to a colloid mill. When using the continuous production method, the water phase and the emulsifier are first mixed evenly, and then the oil is gradually emulsified into the mixture under vigorous stirring. Continuous production is carried out in a vacuum emulsifier, mayonnaise emulsifier, and homogenizer emulsifier. While vacuuming, oil and vinegar are added, and emulsification is stirred. The homogenizing equipment is a shear homogenizing emulsifier. When using the equipment, the homogenizing pressure cannot be too high, generally 8-10Mpa.