Rich and creamy are attributes consumers expect from dairy products, even when formulations feature reductions in fat. Hydrocolloids can assist. They also assist with managing moisture, keeping it bound so there is no liquid layer on the top of yogurt or sour cream, and for ice crystals not to develop in frozen desserts. In beverages, they prevent grittiness by keeping particulates in suspension.
“Hydrocolloids play a variety of roles in various applications, including suspension, protein stabilization, emulsification and texture modification,” said Donna Klockeman, senior principal food scientist, TIC Gums Inc., White Marsh, Md. “How hydrocolloids are utilized ultimately depends on what the texture and stability needs are for the application. Hydrocolloids not only allow for a variety of textures but most hydrocolloids are also excellent sources of soluble fiber.”
Hydrocolloids is a category of ingredients that contributes to the mouthfeel of dairy products by binding water in the system. With milk being about 87% water, hydrocolloids have their job cut out for them.
They are a group of long-chain polymers — polysaccharides and proteins — and are characterized by the ability to form viscous dispersions or gels by binding water. This function is alluded to in the name, where the prefix “hydro” means water and “colloid” means a gelatinous substance.
Hydrocolloids vary in their gelling properties, with their primary use in dairy products being to stabilize and thicken the system, said Amaia Hauet, research and development manager, Ingredia Inc., Wapakoneta, Ohio. Secondary functions include emulsification, aeration, suspension and encapsulation. The functions vary by application and by hydrocolloid.
“Carrageenan is great for chocolate milk applications,” said Ann Tigges, technical services-dairy, Cargill Texturizing Solutions, Minneapolis. “It is the best for suspending cocoa particles, preventing separation and adding mouthfeel in a neutral calcium-rich environment such as milk.”
Locust bean gum and guar gum long have been the go-to hydrocolloids for mainstream ice cream.
“These gums are excellent at trapping water molecules and helping to prevent water migration during the constant freezing, thawing and refreezing inherent to the manufacture, distribution and storage of ice cream,” Ms. Tigges said.
Pectin and gelatin are both popular in yogurt. They work well in low-pH environments and provide desirable sheen. For many, nothing beats gelatin’s melt-in-the-mouth attribute, which makes it very popular in yogurt.
“Pectin delivers ‘spoonability,’ a key attribute consumers expect from yogurt,” Ms. Tigges said. “I’ve seen some yogurt manufacturers combining pectin and agar to replace gelatin. The combination mimics the sheen and cut of gelatin, and has a creamier mouthfeel than just pectin alone.”
But that’s two ingredients instead of simply gelatin.
“No single hydrocolloid can replace gelatin’s unique function in yogurt,” said Lara Niemann, marketing director-Americas, Gelita USA, Sergeant Bluff, Iowa. “Gelatin is also known for giving cream cheese spread and whipped toppings a stabilized foam.”
It was not too long ago that product developers were phasing gelatin out of dairy formulations because of the desire for kosher certification. Recognizing that it’s nearly impossible to duplicate the unique and desirable functions gelatin brings to dairy products, Gelita now produces kosher gelatin.
“Gelatin is a highly purified protein, which depending on the application, can act as a fat replacer; a gelling, binding and whipping agent; a stabilizer; an emulsifier; and even as a film and foam former,” Ms. Niemann said.
Hydrated gelatin contributes lubricity to a system. Together with the melt-in-the-mouth attribute, gelatin makes a choice fat replacer in dairy foods.
“Gelatin provides an opportunity to replace a large percentage of a dairy product’s fat content, since gelatin binds large amounts of water,” Ms. Niemann said. “It creates a fat-like matrix in emulsions by exhibiting shear-thinning properties and creaminess.”
Due to its foam-building properties, gelatin may be used to replace some of the fat content of foamed milk-based desserts, such as mousse.
“These are multi-phase emulsions of air, oil and water,” Ms. Niemann said. “Gelatin decreases the surface tension of the water, enabling a foam to be generated by mechanical whipping or by the injection of gas. It then stabilizes the foam by gelling. In products such as half-fat butter, reduced-fat cheese and fat-free ice cream, gelatin helps minimize the absence of fat without compromising on taste.”
When it comes to mimicking fat in ice cream, such gums as locust bean, tara and carrageenan may provide the desired full-body richness of milkfat, said Joshua Brooks, commercial director, Gum Technology, Tucson, Ariz., a business unit of Ingredion Inc. He cautions, however, that there are different types of carrageenan and they vary in functionality.
“Some are brittle while others are smoother and react with milk proteins,” Mr. Brooks said. “Choosing the right carrageenan or usage level of carrageenan and locust bean gum or tara gum is crucial in creating a texture that is appealing.
“The formulator must also avoid over stabilizing the ice cream, which could create an undesirable gumminess.”
This is why hydrocolloid blends often are used, as many hydrocolloids work synergistically to achieve texture and stability goals that the individual ingredients cannot achieve on their own. With many clean label initiatives, synergistic blends may allow for a simpler ingredient legend.
Ingredia provides a line of hydrocolloid-based functional blends for ice cream and frozen desserts.
“One of our stabilizing blends based on xanthan gum and whey protein works in both dairy and non-dairy ice creams,” Ms. Hauet said. “This synergistic
combination helps control ice crystal growth and gives the final product a smooth, creamy mouthfeel.
“We also offer hydrocolloid blends for reduced- and low-fat ice cream and frozen desserts. It allows for an overrun up to 125% with minimal shrinkage.”
TIC Gums now offers an extended portfolio of high-performance blends for manufacturers seeking to formulate clean label, high-protein, ready-to-drink beverages.
“We leverage our gum acacia technologies to provide stabilization, emulsification and enhanced mouthfeel in high-protein dairy beverages without increasing viscosity,” said Karen Silagyi, product manager at TIC Gums.
“Hydrocolloids can be used at varying usage levels to meet desired formulation requirements,” Ms. Silagyi added. “For example, we offer a system, which depending upon usage level, can make the same yogurt base be either a thick, spoonable yogurt, or a pourable, drinkable yogurt.”
Amanda Wagner, food scientist, Fiberstar, River Falls, Wis., said, “With the food industry trending toward cleaner labels and increased sustainability, product developers are often limited in their choices of hydrocolloids or are unaware of other ingredients that can function as well as or better than their current hydrocolloid formulation.”
Fiberstar markets citrus fiber derived from orange pulp that may deliver similar functionalities as hydrocolloids in dairy applications with the ability to provide a clean nutritional label, said Jennifer Stephens, director of marketing.
Citrus fiber is composed of insoluble and soluble fibers and protein. The unique structure enables it to function like a traditional hydrocolloid. Functionalities include thickening, emulsifying stabilization, reducing syneresis and fat reduction.
“The key to our citrus fiber’s functionality is its surface area, which contributes to the high-water holding capacity and emulsification properties,” Ms. Wagner said. “Certain citrus fibers contain native pectin, which can be activated to produce gelling properties in high-sugar/low-pH food processing conditions.”
Inulin is another fiber with hydrocolloid attributes.
“When used in dairy products, inulin acts as a texture enhancer and a fat replacer, all while mimicking the mouthfeel and creaminess of fat,” Ms. Hauet said. “It is also a soluble fiber that will help increase the fiber content of the final product. Used in high amounts, this ingredient even has a prebiotic effect.”
Synergies, along with added nutritional benefits, are always a bonus, but formulators must always consider the chance of potential negative ingredient interactions. This is particularly true with high-protein and blended protein systems.
“Using a single-source supplier reduces the possibility of negative interactions, over stabilization, or in some cases, the chance of ingredients competing against each other instead of working together,” Mr. Brooks said.
Ms. Tigges concluded, “The creative use of hydrocolloids can provide for an infinite possibility of textures and solutions.”