If you’ve ever opened a carton of ice cream and found an unappealing layer of ice crystals sitting on top, you’ve seen why stabilizers are important. Suppressing this crystal growth during temperature abuse of the product is one role stabilizers play.
“Stabilizers provide two primary functions in frozen desserts,” says Allen Freed, president and CEO, Gum Technology Corporation, Tucson, AZ. “The first is to help reduce the crystal size. The smaller crystal size makes the final product smoother and creamier. Also, since freeze/thaw causes the ice crystals to grow, it is beneficial to start with the smallest crystal possible. Stabilizers also help prevent syneresis, which also leads to large crystals forming, creating a graininess which is not organoleptically pleasant. Stabilizers are also used to create various textures and are used in variegates and inclusions to help keep the variegate from bleeding and spreading into the external phase.”
Stabilizers are often used to impart structure and firmness to ice cream, which assists in packaging. Aaron Venables, senior research scientist, FMC BioPolymer, Princeton, NJ, notes: “This is extremely important in extruded novels such as bars and sandwiches. Maintaining defined shapes and firm edges results in efficient packaging procedures and positive customer perception.”
Stabilizers also help to “suppress the effects of altitude abuse, which reduces the occurrence of shrinkage, control the rate of melt and provide protection against whey separation in resale mix or production facilities that have slow hardening operations,” Venables says.
Just as stabilizers serve multiple functions, they encompass two functional categories—emulsifiers and stabilizers. “These ingredients are often added as a system with both components,” explains Joe Klemaszewski, dairy applications food scientist, Cargill Texturizing Solutions, Minneapolis. “Commonly used emulsifiers include egg yolk, mono- and diglycerides, polysorbates, and lecithin. These surfactants alter the interfacial properties between the three phases present in ice cream: lipid, water and air. The type and level of emulsifier also affects the functionality of the milk protein naturally present. Emulsifiers affect the appearance (dryness), creaminess, air cell size and melting properties of ice cream.”