CHICAGO — Not only do we eat with our eyes, as the saying goes, we also drink with them. This is why many beverages include ingredients that stabilize the system by keeping additives ranging from colors and flavors to vitamins and minerals to fiber and protein in suspension.
“Stabilizers can also enhance the mouthfeel of reduced-sugar beverages, which is a growing area of innovation,” said Brian Surratt, project manager, Cargill Texturizing Solutions, Minneapolis.
Joe Farinella, vice-president of research and development with Imbibe, Niles, Ill., said, “There are a number of reasons a beverage would need to be stabilized. I’d group them into four camps: physical, micro, flavor and appearance. The tools to use vary depending on the attribute you’re trying to stabilize as well as the specifics of the formulation.”
Most formulators agree the greatest stabilizing challenge is with high-protein drinks. This includes beverages designed to refuel, replenish, rehydrate, satiate and nourish.
“With these products, you’re dealing with challenges on multiple fronts from a stability standpoint,” Mr. Farinella said. “Physically you need to have a good hydrocolloid system in place that will ensure the proteins remain suspended for a long period of time. The specific ingredients and ratios used in the stabilizer system vary depending on the needs of the formula and project. Getting this system right is usually the biggest challenge on these projects.
“Low-acid, high-protein beverages require a lot of attention on the processing side to achieve micro stability. The high temperatures needed to achieve micro stability puts stress on the proteins and the stabilizer system. This can negatively impact flavor.”
Another issue such beverages face is discoloration or the development of off colors. The products typically have just the right amount of carbohydrates and proteins that when heat processed, Maillard browning may take place. The right stabilizer with the right protein may prevent or slow the reaction.
“In general, protein drinks are harder to stabilize than other beverages,” said Renata Ibarra, research development and applications senior director of taste, Kerry, Beloit, Wis. “When subjected to ultra-high-temperature pasteurization or retort temperatures, proteins tend to denature and lose some of their emulsifying properties. They also sediment out either immediately after processing or during shelf life at ambient conditions.”
David Sabbagh, senior group manager — innovation, DuPont Nutrition & Health, St. Louis, said, “Especially when dealing with beverages containing blends of different types of proteins, effective stabilization can be difficult, but achievable through emphasis of the right hydrocolloids and emulsifiers along with optimized batching procedures and processes.
“Vegetable proteins and dairy proteins have very different molecular structures. When blended together, those interactions are more complicated than beverages made from sole proteins. Identifying the right stabilizer and right process are critical to success.”
Gellan gum-based solutions have become common in milk alternatives. Most of the almond drinks on the U.S. market are based on gellan gum, alone or in combination with other hydrocolloids.
“Gellan gum has premium stability properties for non-dairy beverages while also maintaining the targeted flavor profile, with excellent particle suspension and low mouthfeel,” Mr. Sabbagh said. “It has a consumer friendly image and has been seen as a possible replacement for carrageenan.”
TIC Gums, White Marsh, Md., a business unit of Ingredion, Inc., is introducing a new stabilizer system designed for ready-to-drink dairy-based protein beverages. Based on gum acacia and gellan gum, the system addresses such challenges as age gelation, protein stabilization and texture. There is a system specific for high-viscosity beverages that also includes guar gum.
“This new product line allows formulators to expand and push beverages into longer shelf life, higher protein content and increased fat levels, while maintaining a clean label,” said Dan Grazaitis, beverage technology manager. “These were challenges the industry previously faced without many solutions.”
Kerry is identifying new ways of managing materials from the source and modifying them in a way to make them more stable in beverages. For example, the company has a new non-allergenic pea and rice protein ingredient that features a synergistic combination of plant proteins to deliver a complete amino acid profile that is closer to milk protein. The new protein and stabilizer system helps keep the protein stable and suspended during and after heat treatment.
“It works well in high-acid protein beverages,” Ms. Ibarra said. “We found that addition of this polysaccharide blend reduced chalky mouthfeel and improved overall acceptability.”
There is a great deal of innovation taking place in protein beverages that bring juice and dairy together. In these acidic, smoothie-style beverages, protein readily precipitates out of solution, resulting in a chalky taste.
“To stabilize proteins in this pH environment, product developers turn to high methoxyl pectins,” said Wen Shieh, technical leader for fruit, beverage and confections with Cargill Texturizing Solutions. “These pectins coat the surface of the protein, preventing sedimentation problems.”
Kerry recently developed a system for whole grain dairy-based protein beverages that delivers 8 grams of whole grains and 8 grams of milk protein per 8-oz glass. It is designed to withstand the rigors of ultra-high-temperature pasteurization.
“We stabilize whole grain oats and milk protein with gellan gum and a cellulose blend, a combination that works similar to carrageenan,” said Neeraj Sharma, senior research development and applications scientist at Kerry. “The system keeps the insoluble grain particles suspended uniformly to create homogeneity during processing and ensure a pleasant drinking experience.”
Increasingly consumers want beverages with less sugar and fewer calories. That demand has many beverage companies searching for options to keep sugar levels in check, while still delivering the same taste and sensory experience as a full-sugar beverage. Often the beverages are enhanced with functional ingredients that bring additional issues to tackle.
“Nutritional beverages comprised of healthy functional ingredients can be challenging to manufacture in a way to ensure stability over shelf life,” Mr. Sabbagh said. “This can be due to interactions between functional ingredients and other ingredients in the formulation, which may affect flavor and texture attributes.”
When it comes to reducing sugar, maintaining mouthfeel is one of the most significant challenges, said Mr. Shieh. To help deliver on consumers’ mouthfeel expectations, Cargill developed a proprietary technology that uses tribology to shorten product development time.
“When you reduce the sugar in a beverage formulation, consumers often find mouthfeel to be lacking,” he said. “By incorporating hydrocolloids into low-caloric beverages, we can restore the mouthfeel to the beverage.”
Kerry developed a reduced-sugar, lower-fat, strawberry-flavored protein beverage using a stabilizer system composed of a cellulose blend and carrageenan. The protein comes from nonfat dry milk, and canola oil is the source of fat.
“New enhancements in cellulose technology allow for a texture and mouthfeel similar to a full-sugar beverage,” Mr. Sharma said.
In neutral pH beverages containing protein and electrolytes, carrageenan has long been the go-to hydrocolloid for stabilizing proteins and providing properties such as desirable mouthfeel, thickness and viscosity, said Mr. Surratt.
“Over the course of a beverage’s shelf life, protein stabilization is critical in these types of beverage,” he said. “Factors such as high-water content, low-viscosity medium, ionic strength, and lipid and particulate suspension are the most common ‘pieces’ for scientists to manage. Control measures such as carrageenan help solve this stabilization puzzle.”
Because of its charge density, carrageenan helps keep particles such as potassium, calcium, magnesium and proteins in suspension.
“These same electrostatic interactions enable carrageenan to entrap insoluble particles such as cocoa, or calcium salts used to fortify dairy and non-dairy beverages, as well as lower density constituents, such as fat globules,” Mr. Surratt said.
Paige Ties, senior technical service specialist — research and development at Cargill added, “Carrageenan is often used with chocolate milk to help stabilize cocoa. Without carrageenan, the cocoa falls out of solution and forms a layer across the bottom of the container.”
Soft drinks have their own set of issues, mainly with flavor and color stability.
“Flavor emulsions and neutral cloud for soft drinks require stabilizers to help maintain the emulsion formed in these products prior to their addition in the final formulas,” Ms. Ties said. “Specifically, nOSA (n-octenyl succinic anhydride) starch is commonly used to stabilize these products. This starch works as an emulsifying agent, stabilizing the oil in water emulsion. The nOSA starch helps by decreasing the interfacial energy between the oil and water, increasing the oil droplet’s density and slowing the oil’s mobility.”
Growing consumer demand for simplified ingredient statements adds another layer of complexity to beverage formulation. When reformulating products with clean-label ingredients, formulators must remember the entire product may change, and it may change over shelf life.
“Formulators should evaluate stability solutions early on in projects through accelerated shelf life testing,” Mr. Farinella said. “This is especially true for protein-containing beverages. Samples should be produced at plant scale to account for the added temperature and shear abuse typically experienced during commercial production.”