Wanting It All
by Lori Dahm
The latest trend in ice cream is removing sugar and fat without compromising taste.
Consumers want to have their cake and eat it with ice cream, too. Despite the health focus that predominates in the market, consumers are still in love with dessert.
Now, with issues of obesity and health in the forefront of public awareness, consumers want products that are indulgent, but also offer an improved nutritional profile. Ice cream is one area that is demonstrating many new product introductions and innovative formulations in this regard. The trend of no-sugar-added ice cream and lower-fat ice cream products comprises almost half of the ice cream freezer case these days.
In the past, consumers who chose to satisfy their sweet craving with such products had to suffer through dismal texture and inferior taste. But now, the latest innovations in texturing ingredient blends and new technologies have significantly improved the mouthfeel of these “better-for-you” ice cream products.
The result is win-win for the consumer, and an expanding market for the experts who supply the sugar replacement and texture ingredients to ice cream manufacturers. It’s a complicated proposition to compensate for all of the sensory attributes provided by full-fat or full-sugar ice creams, but thanks to continually improving technology, the products in the freezer case today offer consumers a taste experience that is almost akin to the real thing.
Texture Trials
When ice creams are formulated with sugar-replacement ingredients to deliver a lowered sugar content, or less butterfat to achieve a lowered fat content, texture issues arise which are undesirable.
“Eating quality suffers when you drop out the sugar or fat from an ice cream product, because what you are doing is decreasing the solids, which alters the freezing point of the ice cream,” says Chip Venables, senior research scientist at FMC BioPolymer, Princeton, N.J. “Whereas sugar lowers the freezing point, an ice cream without sugar has a sharp increase in its freezing point which causes the product to become hard and crumbly.”
This decrease in solids leads to issues of ice crystal formation; when the ice cream is lower in total solids there is more free water in the system. Similar problems arise from a lowered fat content, which often causes the richness and full body typical of full-fat ice creams to disappear.
“The ice creams that are lower in fat typically have more air in the product, which causes a decrease in mouthfeel and a weak body,” says Gwen Meyer, technical director for dairy applications at Kerry Bio-Science, Hoffman Estates, Ill. “Effective formulations of lowered-fat ice creams must build that body back up with emulsifiers and texturizer systems that mimic high solids and higher fat and help the product eat more like regular ice cream.”
Finding the proper blend of emulsifiers and texturizers to offset these effects is essential to creating ice creams that consumers will find acceptable in comparison to regular counterparts. Together with other issues such as accounting for the desired overrun and achieving the desired viscosity for proper manufacturing, or eliminating shrinkage after freeze/thaw cycles in distribution, the world of low-sugar or light ice cream formulations becomes a quagmire of formulation pitfalls that are best left to the experts to navigate.
“There are many scenarios to account for when altering the sugar or fat content of ice creams. There are hundreds of different emulsifiers and hydrocolloids, and different combinations really move the needle in many different directions,” says Don Heffner, market manager for frozen dessert at Kerry Bio-Science. “We can create something with more melt, something that will never melt, something icy, something not icy. Whatever our customer wants to bring into a product and whatever those attributes are, we formulate against that to create a distinct stabilizer package.”
High Intensity
The sugar-replacement ingredients that are used in the lowered-sugar or no-sugar-added ice creams are generally one of two classes: sugar alcohols or high-intensity sweeteners. With either of these sugar substitutions, bulking agents are often required, and a corresponding stabilizer package is necessary for the ice cream to run through equipment properly and to deliver the proper eating experience.
“Splenda is an ideal ingredient for a healthier rebalance ice cream product because it replaces the sugar,” says Lori Napier, manager of new technology development at Tate and Lyle, Decatur, Ill. “We have ingredient packages that are designed to work together with Splenda to deliver the same rich, creamy and desirable mouthfeel and texture characteristics of full-fat ice cream, but in reduced-fat or reduced-sugar varieties.”
Often the ice cream products that use Splenda as a sugar replacement use polydextrose to provide bulking, because polydextrose has many of the freezing point characteristics of sucrose. Like sucralose, polydextrose also blends well and can be processed within the regular pasteurization and homogenization processes. Polydextrose has a low caloric content and is absent of sweetness. Maltodextrin can also be used in conjunction with Splenda, particularly in lowered-fat ice cream products, because it helps deliver desirable mouthfeel.
“Oftentimes it isn’t a single bulking agent that replaces those textural characteristics,” says Napier. “We see a combination of polydextrose, maltodextrin and the sugar alcohols, which gives you the right combination of ingredients for the right texture and freezing-point depression.”
Tate and Lyle Rebalance is a line of sweetening and texturizing blends appropriate for a variety of food applications where the desire is to reduce sugar, fat and calories. Ice Cream Rebalance 500 is a specific solution designed for ice cream.
“Our Rebalance 500 is part of a program that responds to the trend of taking products currently on the market that may be high caloric or high sugar or high fat content and trying to modify and rebalance them so that these contents are at a more desirable level nutritionally, while the product remains indulgent in taste,” says Robert Olson, Tate and Lyle advanced technical resources, R&D. “The Rebalance solution set for ice cream, for example, contains some of the starches that we’ve found work well in dairy systems, replacing some of the mono and diglyceride ingredients that are typically used in these formats.”
Sugar Alcohols
While the past 15 years has primarily seen the use of sorbitol as the sugar alcohol used for the no-sugar-added ice cream formulations, new sugar alcohol solutions are now available and preferred.
“Sorbitol is a smaller molecule than sucrose, a monosaccharide rather than a disaccharide, so it decreases the freezing point even more than ice creams with regular sugar. To readjust the freezing point when using sorbitol, ice creams would include maltodextrin and polydextrose as bulking solids, and a high-intensity sweetener because the sweetness level wasn’t high enough — often four ingredients to use sorbitol,” says Ron Deis, vice president of technology at SPI Polyols, New Castle, Del. “Now we’ve developed a new product called Maltisweet IC, which is a maltitol syrup. This has the same molecular weight distribution as sucrose and corn syrup used in regular ice cream, so the freezing profile, characteristics and the texture of the ice cream remains pretty much the same as regular ice cream.”
Maltitol is 90 percent as sweet as sucrose, and replaces sugar in systems without requiring high-intensity sweeteners. “Since maltitol is a disaccharide like sucrose, and the maltitol syrup has a high molecular weight portion like corn syrup, that results in an almost identical functionality result in terms of sweetness, texture and shelf life,” says Deis.
One effect of using maltitol or any polyol in ice cream formulations is that because hydrogenation blocks the reactive groups that participate in browning, vanilla ice cream may appear whiter, and flavors may need to be readjusted.
Fibers
Another sugar replacement option is inulin and oligofructose fibers, used as bulking agents in conjunction with high intensity sweeteners. These ingredients have characteristics which help offset some of the sensory pitfalls of no-sugar-added ice creams.
“Raftilose P95 is a short-chain inulin which is 30 percent as sweet as sugar, and it depresses the freezing point of reduced-sugar ice creams, preventing some of the ice crystal formation that occurs from fluctuations in temperature during distribution,” says Hilary Hursh, senior scientist at Orafti Food Ingredients, Malvern, Pa. “Raftiline GR is an inulin which is 10 percent as sweet as sugar, and is also used in these applications. Also, these ingredients act as stabilizers to help emulsifying systems in the ice cream mix.”
Raftilose and Raftiline also cover the off-notes of high-intensity sweeteners, rounding out the flavor. This flavor masking also translates in soy ice creams, and has synergy with fruit flavors to help “fruit” notes emerge more strongly.
“Raftilose 95 may affect the viscosity of the ice cream mix because of its solubility, but if a lower level of the high intensity sweetener is desired then we recommend it,” says Hursh. “On the other hand, Raftiline GR is less sweet by itself and has no effect upon viscosity, but requires more of the high-intensity sweetener.”
Keeping it Together
The rest of the equation is the stabilizer systems used with sweetener replacements. These are essential for keeping fat and water dispersed evenly in an emulsion, and then binding the free water after freezing and hardening so ice crystal formation is negligible.
“One key consideration with a stabilizer system is to create a product that will flow and not clog the pasteurization system. You must have a viscosity thin enough to process. Some stabilizers for no-sugar-added ice creams bind quite a bit of water or are not quite as soluble,” says Meyer. “They may even striate in the hold tank. After the freeze, in the hardening stage, it is important to know how that system will work to further minimize ice crystal formation. The stabilizer system is also key in preventing heat shock in the field, where a lot of product degradation can occur. But a good food scientist is aware of these things and can formulate for them quite easily.”
In the past, because distribution systems were lengthy, stabilizer systems would be insulated to last through different stages and impart the proper water binding and prevent ice crystal growth throughout a long shelf life. Now, the newest innovations create smaller air cells and extremely fine water crystals, which results in improved texture.
“Gelstar is our line of five or six different stabilization blends for these ice cream applications, which retains small air cell size during heat shock abuse and altitude abuse, helping with the perception of a rich and creamy product by means of a small, uniform air cell size,” says Venables. “These stabilizers are based on microcrystalline cellulose, and their function is based on a network of insoluble crystals which are very effective in binding large amounts of water to deliver a product that behaves like a solid.”
The food science behind formulating no-sugar-added ice creams is complex, and the combination of texturizers and stabilizers that can be used with sugar replacements is vast. The proper formula depends on the goal of the manufacturer and the sensory attributes they are trying to achieve.
“The lowfat and no-sugar-added ice cream product category is thriving,” says Venables. “The biggest need in the market today is developing ice cream products that have the quality of a 12 percent butterfat product but with less fat — maybe a 5 percent system delivering that same premium mouthfeel. That is what a lot of folks are trying to do, and it’s what consumers are demanding.”