By Cindy Hazen, Contributing Editor
The definition of ice cream is as rigid as a block of ice, as laid out in the product’s standard of identity. But just because a product is entrenched in regulation and tradition doesn’t mean it must be totally boxed in. Ice cream and frozen desserts provide innumerable formulating options, from healthy to decadently delicious.
Healthier indulgence
In fact, “the most prominent change has been the move away from standard-of-identity ice cream," says Jonathan Hopkinson, Ph.D., senior applications scientist, frozen desserts, Danisco USA, New Century, KS. “Products with lower fat and dairy solids are leading this trend."
Fat is key to the perception of richness and creaminess, and the flavor profile. “Attempts at the direct replacement of fat by a non-lipid component with similar characteristics have failed and no others are in sight," says Bruce Tharp, owner, Tharp’s Food Technology, Wayne, PA.
Flavors for low-fat ice cream need more fullness than those with high fat. One might add more dairy, cream and butter notes in a flavor. Janice Bryl, flavor chemist, Synergy Flavors, Wauconda, IL, suggests that adding lactones in any fruit-flavored ice cream will add fullness. “Vanillin, when added to fruit, vanilla and chocolate flavors, will add sweet vanilla notes that, in turn, will add more fullness, sweetness and creaminess to low-fat ice cream," she says. Flavors with buttery or even cheesy notes like acetoin or butyric acid will also impart richness.
Modifying the sweetener system to reduce calories is no easy task. Besides considering the flavor impact, the developer must take into account water management and the freezing profile. The molecular weight of carbohydrate sweeteners and the degree of polymerization can influence water behavior. High-intensity sweeteners, such as aspartame, sucralose and acesulfame K, do not contribute solids to the mix.
“When you reformulate ice creams to reduce the fat or sugar content, the total solids must be replaced to retain the freezing and eating characteristics of the product," explains Donna Klockeman, dairy scientist, TIC Gums, Belcamp, MD.
One option for the replacement of solids is hydrocolloids. “Since hydrocolloids contain soluble fiber, their use can enhance the healthfulness of the product," Klockeman explains. “Hydrocolloid options for this function include inulin, gum acacia and resistant starches. These hydrocolloids interact with water like the removed sweeteners, but they do not add excessive viscosity to the mix. In reduced-fat formulations, hydrocolloids in combination with emulsifiers are used to mimic the freezing, eating, melting and flavor-release characteristics of higher-fat products. Like sweeteners, hydrocolloids interact with water to help manage the development of coarse and icy texture throughout the frozen product shelf life."
Hopkinson says fiber is one of the easiest additions to ice cream. “Besides the health benefit, fiber functions in ice cream as an excellent bulking agent," he says.
While it is an easy substitution, it’s not without limit. “The formulator must be conscious of cost and the amount of free water in the formulation," Hopkinson says. “The type and amount of fiber used can cause some negative side effects for the consumer, like diarrhea and flatulence. Generally, a level of fiber between 2% and 6% in the ice cream mix is a good place to start."
Back to basics
Short, simple ingredient statements are becoming increasingly important in today’s marketplace. Consumers are looking for ingredients they perceive as natural, like milk, cream, sugar and buttermilk. But natural is in the eye of the beholder since there is not a legal definition for the term. “Often, it’s not natural in the sense that it comes directly from nature that the consumer is looking for. It is how familiar the ingredient is," says Hopkinson. “An example of this is rhamnogalacturonan. It would probably not be considered natural. If the same material is called by its common name, pectin, it is almost universally considered natural."
Gelatin is another stabilizer that consumers recognize. Mindi McKibbin, specialist, edible technical services, Gelita USA, Sioux City, IA, suggests it’s an especially good choice for ice creams because it can be used singly “or with only one other hydrocolloid. Many current ice cream products contain many hydrocolloids."
In ice creams and frozen dairy products, gelatin assists in freeze/thaw stability, as it influences the size and distribution of ice crystals that are formed.
Collagen peptides are proving to have an impact on ice-crystal growth. In a 2007 study, researchers produced collagen peptides (gelatin hydrolysate) by enzymatically treating gelatin samples. They found that collagen peptides with 2,000 to 5,000 Dalton (Da) molecular weight averages worked best at inhibiting ice-crystal formation (Journal of Agricultural and Food Chemistry; 55:10,918-10,923).
“It’s important to remember gelatin also has this functionality, thus a combination of gelatin and a collagen peptide may work best at inhibiting ice-crystal formation," McKibbin. says.
Most hydrocolloids are natural products “derived from tree saps or extracts of seeds, fruits or seaweeds," says Klockeman. “The most-common hydrocolloid seen as an ingredient in retail-branded, all-natural ice-cream products is tara gum. The hydrocolloids, which are used individually or in blends for all-natural ice creams, include locust bean gum, guar gum, tara gum, gum acacia and carrageenans."
Alternative ice creams
Many seeds and nuts contain protein and sugars that can be extracted to make a substance that resembles milk. Soy, rice, almond, hemp and coconut have been used in frozen desserts.
“The developer should keep in mind that, although these products resemble milk in some attributes like protein content or color, they are not exact matches for milk. Many of these products contain oil, for instance," Hopkinson says. “This oil may not melt at the same temperature as the main source of fat in the product, and this may cause problems with whipping or stability. Often, these products contain flavors that may be objectionable. With careful selection and attention to ingredient quality, though, excellent products can be made from these ingredients."
Klockeman notes food scientists have developed alternatives to butterfat that provide similar melting behavior in frozen products like ice creams. “Care must be taken to replace the protein and total solids that are traditionally contributed by the dairy portion of the ice-cream mix," she says. “As is the case with reduced-fat and -sugar products, hydrocolloids can play a functional role in the replacement of total solids. Hydrocolloids in combination with emulsifiers function in these alternative products to deliver similar mix viscosity, freezing characteristics, melting properties and overrun stability to these alternative products."
Balancing flavor can be challenging. “You have to mask the off notes in the base before you add the flavor, and use flavors that complement the base notes, like nuttiness of almond and rice," says Margaret Walther, applications technologist, Synergy Flavors. “It’s difficult to complement the off notes of soy."
There are also “more restrictions on the actual flavor, such as GMO and kosher, when using those bases," says Peggy Pellichero, senior food technologist, dairy team leader, David Michael & Co., Philadelphia.
Boosting beneficial bacteria
Ice cream is an excellent venue for the addition of probiotics, as they survive the freezing process quite well and, once frozen, remain viable throughout shelf life. “Most often they are added just prior to freezing, similar to a flavor," Hopkinson says. “When adding probiotics, the amount added will be determined by the number of organisms needed per serving of final product. Since probiotics in general do not grow in ice cream, this is a fairly simple calculation. Often, there is some die-off during the mixing, pumping and freezing process. A small amount of extra bacteria are usually added to ensure that, at the end of shelf life, there is the proper amount remaining in the product. Factors such as product pH, flavor, oxygen content, the amount of agitation or pumping, and other processing factors will determine the amount of overage necessary. Interestingly, fibers such as polydextrose and bulking agents help prevent some of these problems."
Adding pizzazz
Despite healthful enhancements, most people buy ice cream for the pleasure of eating it. Incorporating fruit or nut pieces, cookie dough or other inclusions creates a seemingly endless variety.
Inclusions and flavors go hand in hand. “They almost need each other," Pellichero says. “Flavors help to enhance the inclusions, and inclusions help round-out the flavor of the ice cream. Think about strawberry ice cream. It’s much better to have strawberry pieces in a strawberry-flavored ice cream than just the flavored ice cream on its own. The look is more appetizing, too."
However, the flavor of the ice cream must be balanced with the flavor of the inclusion. “Contrasting ice creams and inclusions are more difficult to balance," says Walther. “For example, with a peach base and raspberry inclusion it may take several iterations to optimize the profile of the two together."
When adding fruits or nuts, consider their shelf life and piece integrity. “Through the addition of sugar and hydrocolloids, the fresh structure of fruits is maintained through thermal processing required for preservation," says Klockeman. “Hydrocolloids are known to form stable, thin films that are impermeable to oxygen. These hydrocolloids, like gum acacia, are used to form a protective coating for nuts to help control lipid oxidation. This procedure is used in the production of panned, coated nuts and confectionery products (chocolate-coated peanuts) that are added to ice cream as inclusions."
Selecting the right variegates is critical to product success. One of the biggest challenges is ensuring they don’t get soggy. “That is why many products are oil-coated or panned specialties," says Dennis J. Reid, vice president, marketing & business development, SensoryEffects, flavor systems, Bridgeton, MO. “There are textured variegates available nowadays that entrap the inclusions in the fat-based swirl variegate, which forms a very effective moisture barrier and keeps them from getting soggy. The one challenge here is that these products need to be tempered and handled very carefully to assure proper incorporation. The inclusions and textures in these products also tend to be smaller pieces because they have to be able to pass through a variegator nozzle instead of being added directly to the mix as an inclusion."
Melt point is also a consideration. “Lower melt point, compound-coating-based products designed to melt at around 80ºF are designed for use in ice cream or as an add-in for soft-serve applications," Reid says. These can also be used topically. Compared to real chocolate chips, these “provide more versatility, a better melt profile and enhanced flavor release," he says.
Cindy Hazen, a 20-year veteran of the food industry, is a freelance writer based in Memphis, TN. She can be reached at cindyhazen@cs.com.
Ice Cream Standards
The standard of identity provided by FDA lays out strict criteria that must be met before a manufacturer can call a product ice cream. For starters, it must contain not less than 10% milkfat, not less than 1.6 lbs. of total solids to the gallon and must weigh not less than 4.5 lbs. to the gallon (Title 21of the Code of Federal Regulations, Part 135).
FDA permits the use of descriptors for ice cream. Reduced-fat ice cream contains at least 25% less total fat than the referenced product. Light ice cream contains at least 50% less total fat or 33% fewer calories. Low-fat ice cream contains a maximum of 3 grams per ½-cup serving. Nonfat ice cream contains less than 0.5 grams of total fat per serving.
