7EmulsificationThe phospholipids, lipoproteins and proteins found in egg yolks are surface active agents that enable the formation of emulsions from immiscible liquids such as oil and water.Egg yolks can be used to fortify whole egg blends to increase emulsifying actionNo essential differences are found in emulsifying properties of dried whole egg and yolk and fresh liquid eggs4.640
8Emulsions/Surface activity- a stable mixture of two immiscible liquid phases, one which is dispersed in the otherMayonnaise
9Emulsification Applications Mechanisms Mayonnaise Hollandaise sauce Salad dressingsBaked goodsMechanismsEgg emulsifying properties come from the yolk
10Emulsifiers in the egg yolk Phospholipids-lecithinLipoproteinsProteins- having hydrophilic andhydrophobic regions
12Good Stable EmulsionShould be viscous to hold suspended ingredients in placeDroplets dispersed (oil or water) should be small enough to remain in suspension and should be evenly distributed throughout the matrix
13Emulsions Factors affecting emulsions Viscosity (Stability over time) Amount of emulsifier (Formation and Stability)ratio of emulsifier/fat/waterAdditives0.05% sodium-2-lactylate increases emulsion stability
14Mayonnaise is made by combining lemon juice or vinegar with egg yolks. Eggs (containing the emulsifier lecithin) bind the ingredients together and prevent separation.Adding oil too quickly (or insufficient, rapid whisking) will keep the two liquids from combining (emulsifying).As the sauce begins to thicken, oil can be added more rapidly. Seasonings are whisked in after all of the oil has been added.
15Long shelf life (1 year), functionality, variety blends
16FROZEN EGG PRODUCTSFrozen yolk has 10 % salt or sugar added to prevent irreversible protein gelation. Result is a smooth creamy, viscous yolk.
17Egg ProductsSanovo Foods produces enzyme-modified product Heat-stable egg yolk.Uses enzymes to degrade phospholipids phospholipids which account for 7-8% of the egg yolk. The enzyme converts a large part of the lecithin in the egg yolk into lysolecithin, which has much better emulsifying properties.
18Mayonnaise Cheese Cake Cinnamon rolls Made with liquid frozen whole eggMade with liquid frozen salted egg yolkCheese CakeCinnamon rollsMade with liquid frozen sugared egg yolk
19Some common applications of emulsifiers Bread It is possible to make bread without emulsifiers but the result is often dry, low in volume and easily stales. As little as 0.5% emulsifier added to the dough is enough to achieve an enhanced volume, a softer crumb structure and a longer shelf-life.Chocolate All chocolate products contain 0.5% of lecithin. These emulsifiers are added to provide the right consistency of the chocolate, so it can be molded into plates of chocolate, chocolate bars etc.
20Some common applications of emulsifiers Ice-cream Ice-cream: both a foam and an emulsion it contains ice crystals and an unfrozen aqueous mix.Emulsifiers are added during the freezing process, to promote a smoother texture and ensure the ice-cream does not melt rapidly after serving.They also improve freeze-thaw stability. All this applies to other desserts such as sorbet, milkshake, frozen mousse and frozen yogurt as well.