Stabilizers
reduce the chance of syneresis, which some consumers find undesirable.
Complex distribution systems and lengthy product shelf lives need not concern dairy processors who avoid ingredients that some consumers perceive as being fake, artificial, too chemical sounding, etc. That’s because there are a variety of natural ingredients capable of stabilizing and emulsifying dairy foods without raising the eyebrows of even the most discerning consumers.
Stabilization of dairy products, which complements the emulsification of the oppositely charged components (oil and water) of many dairy systems, is becoming increasingly important as opportunities for product innovation present themselves. Performance expectations are more specific and product labeling is more demanding. The most discriminating formulators know that to meet consumers’ expectations, cocoa particles should not separate out in chocolate milk, minimal whey should be floating on the top of yogurt and ice crystals should be so small in frozen desserts that the tongue cannot detect them.
Stabilizers ensure a dairy foods’ aesthetics. They enable a manufacturer to provide consumers a product that looks like it did when it was first produced, in spite of the fact it has been through transportation, handling and time on a shelf or in a freezer. Stabilizing ingredients assist with building body and texture, increasing product viscosity, reducing ice crystal development, preventing syneresis, and more.
Wonderful whey
What’s more natural than stabilizing dairy foods with a dairy-based ingredient? That’s exactly what whey proteins are capable of doing. When whey protein concentrate is used to stabilize yogurt, manufacturers see a noteworthy decrease in syneresis during the yogurt’s shelflife. Research shows that syneresis is cut in half when milk for yogurt is fortified with 4% whey protein concentrate, as compared to 4% skim milk powder. The higher protein whey protein concentrates (80% protein, or WPC80) also provide textural benefits in yogurt including enhanced gel-forming properties.Whey proteins can stabilize frozen desserts, too. The whipping ability and foaming function of whey proteins adds to desirable performance during freezing and enhances air incorporation. Whey proteins increase the viscosity of the unfrozen portion of the mix, and thus help stabilize and strengthen air cells. This helps in retaining air and helps prevent the collapse of structure, or shrinkage. When small air cells are created and maintained, smooth and creamy ice cream results. Resistance to heat shock is also enhanced.
Whey proteins happen to be very efficient emulsifiers, too. They readily form stable emulsions and can be used to totally or partially replace chemical emulsifiers in frozen dairy desserts. Additionally, the bound fat in whey products is relatively high in phospholipids such as lecithin, adding to the emulsification capacity of whey ingredients.This is particularly helpful in a mix intended to be packaged for freezing at another location at another time.
Whey proteins are often used in the many types of processed cheese in the marketplace. Their use typically results in superior flavor, body, and texture, as well as improved sheeting, slicing, shredding, spreading and melt performance, as compared to cheeses not made with whey proteins. When properly formulated, other more expensive stabilizers and emulsifiers can be totally or partially removed from formulas, thereby reducing total formula costs.
No shells to crack
Direct from Mother Nature is the egg. Egg products, a more convenient form of shell eggs, can assist in the stabilization of creamy dairy products such as ice cream. Specifically, it’s the yolks that are superior emulsifiers. The phospholipids and lipoproteins in the yolk serve as surface-active agents, stabilizing milkfat with water. By doing so in ice cream mix, the yolk helps eliminate crystallization and decreases the melting point. Formulators often use frozen egg yolks or powdered egg yolks because the egg yolk solids improve the whipping ability of the mix. Usually not more than 0.5% is needed for this purpose. Investigations have shown that egg yolks improve the rate of whipping more if they are sweetened with 10% sugar before being frozen, according to the American Egg Board, Park Ridge, Ill.In ice cream, the addition of egg yolk solids can improve the product’s appearance when it is melting and its overall texture. In all cream-style dairy products, the rich color of yolk transfers to the dairy base, increasing its visual appearance and perceived richness.
Egg whites, which are primarily protein, create very stable foams when they are whipped. They can add stability to refrigerated dairy products, such as custard, mousse, pudding and whipped cultured products. Egg whites also coagulate and thicken custards, flans and puddings.
Multi-functional lecithin
One of the components of whey protein and egg yolk that make them such great emulsifiers is the phospholipid lecithin. Neither whey nor egg lecithin is an economical ingredient to produce and sell, but lecithin from soybeans is. Lecithin’s multi-functionality can help lower production costs while enhancing foods’ functionality, and at the same time still be label friendly.Soybean lecithin is used throughout the food industry as an emulsifier to promote even blending and mixing. In whipped dairy products, lecithin enhances structure and firmness, contributing to the stability of the product.
Lecithin acts as a release agent to ensure clean separation. For example, when applied directly to products such as processed cheese slices, lecithin helps form a stable film barrier that prevents them from sticking together.
Stabilizing
ice cream keeps inclusions in place, prevents shrinkage in the freezer and
slows ice crystal development. Photo courtesy of Dreyer’s Grand Ice Cream
Holdings Inc.
Pectin, gums and blends
Pectins, too, are a label-friendly ingredient that can function as a thickener, gelling agent and emulsifier due to its multi-functional nature. Pectins are derived from plants, with most consumers having heard of apple pectin. Pectins can achieve a range of textures. By considering the dairy system’s conditions, including solids, pH and other ingredients, as well as various processing parameters, most importantly temperature, formulators can select the ideal pectin for an application.Pectins stabilize fruit preps for yogurt and ice cream. Fruit prep gels should be firm enough to suspend the fruit uniformly, yet be thixotropic enough to allow pumping and stirring. Alone or in combination with other stabilizers, pectins control syneresis and reduce color migration from the fruit prep into the dairy phase.
Pectins also enhance the mouthfeel of dairy-based beverages. They stabilize acidic dairy beverages such as yogurt drinks, milk and juice combinations, and the new generation of whey protein beverages invading the marketplace.
Most gums are considered to be all-natural stabilizers, and many have application in dairy foods. Locust bean gum, which is extracted from the carob pod seeds grown on the carob tree, is also a source of soluble fiber. This long-chain polysaccharide is capable of binding large amounts of water as it hydrates. In ice cream, locust bean gum is very effective in preventing syneresis and for controlling the formation of ice crystals as the finished product goes through freeze-thaw cycles.
Locust bean gum is often used in dairy systems with other gums for synergistic functionalities. On its own it does not form a gel, but when combined and heated with microbial-produced xanthan gum at a 1:1 ratio, it will form an elastic gel, much like gelatin. Typical applications include cream cheese, refrigerated dairy desserts, ice cream and the fruit preps that go into these products.
On its own, xanthan gum develops a very high viscosity, even when very little is used. When mixed with guar gum or locust bean gum, the viscosity is more than when either one is used alone, so less of each can be used. Guar gum, too, has an extremely high water-binding capacity, providing very high viscosity in water-based systems even at low dosage levels.
Carrageenan, which is produced from red seaweed, is used in a variety of dairy applications. One of its most common applications is chocolate milk, where it keeps cocoa particles in suspension.
There are many very effective stabilizers and emulsifiers available to food formulators, as well as many more that are considered natural. This discussion simply provides a glimpse at some of the consumer-friendly ingredients available to formulators. Selection is based on formulation and marketing objectives, and of course bottom line. To see the ingredients that natural foods leader Whole Foods does not allow in any of the foods it stocks, visitwww.wholefoodsmarket.com/products/unacceptablefoodingredients.html.
