There could not have been a better person to formulate Eli's no-sugar-added plain cheesecakes than Diana Moles, research and development manager at Eli's Cheesecake Co. (Chicago). “I hate the taste of diet products,” says Moles. She is so disturbed by aftertastes that she personally avoids diet gums, sodas and foods. Consequently, when given the mandate to formulate no-sugar-added and low-carb cheesecakes for diabetics and others who must restrict sugar intake, she had to form allegiances with those same sweeteners she had previously avoided. Recognizing that Eli's customers would feel similarly, Moles sought to retain the most important characteristics of Eli's traditional cheesecakes—taste, texture and appearance.
In the beginning, Moles experimented with many different sweeteners including sucralose, which has demonstrated success as a sugar replacer in many consumer products. However, she was not satisfied with the outcome and continued to look for a sweetener system that could provide a number of properties.
“I was looking for a good browning agent, emulsification and structure. But the main thing [I wanted] was flavor with no aftertaste.” After trying a series of sweetening systems over a four-month period, Moles settled on a recipe that blended lactitol and aspartame with polydextrose. Aspartame, used for other Eli recipes, imparted the sweetness while the polydextrose, she felt, acted as a “binder” to protein.
“The cake was beautiful. It looks like the real McCoy, and it tastes like the real McCoy,” says Moles. After a year of success on the market, Eli's no-sugar-added cheesecake has spawned a chocolate flavor and inspired Eli's to formulate a low-carb cheesecake that replaces carbohydrates with polydextrose and lactitol.
Food formulators are familiar with Moles' challenge, given that replacing, reducing and eliminating many ingredients is now in vogue among U.S. processing companies seeking to join the 'low-carb' revolution. Today's emerging formulation edicts impact a processor's ingredient choices for brand and line extensions that often go beyond low-carb or the replacement of sugar.
The current challenges facing food formulators are due to changing trends in nutrition, says K. Scott McKenzie, Ph.D., associate director of the Food Protein R&D Center at Texas A&M (College Station, Texas). The misconception formulators take into a food reformulation is that the project will be as simple as replacing one or two ingredients, the way you would switch blueberries for strawberries in a muffin recipe.
Oftentimes, when subtracting carbohydrates or increasing protein content, “manufacturers have a fundamentally new product that won't resemble the old product,” states McKenzie. “They are different and physically they behave differently during processing.” Most importantly to consumers, they taste differently, which is exactly why many of the low-fat products of the 80s and 90s were abandoned.
As for the excluded ingredients, such as carbohydrates that impact the character of the original product, manufacturers are trying their best to find equivalents. Some equivalents satisfy their nutritional requirements, but not the functional attributes. “Regardless of how nutritious it is, if it doesn't taste good, the consumer is not going to eat it,” says Ernesto Hernandez, Ph.D., head of the fats and oils program at Texas A&M University.
A Sweet Tradeoff
Colleen Zammer, principle of food and beverage technology at Tiax LLC (Cambridge, Mass.), believes the goal is to achieve a synergistic system by obtaining the right sweetener and the right amount of sweetness, so that consumers get an initial hit of the targeted taste. “All of that should carry over into the aftertaste so that it doesn't linger around, and what you end up tasting is the good [taste].”Aspartame is composed of two amino acids, aspartic acid and phenylalanine, and is about 150-200 times as sweet as sucrose. Unlike aspartame, the chemical structure of sucralose, which is roughly 600 times as sweet as sucrose, more closely resembles sucrose. “One of the benefits of sucralose is that it can withstand high temperatures, like the heat of baking,” notes Zammer. “Aspartame cannot—it is only stable for so long before it degrades. Because of that, sucralose has a good flavor profile and a lot of versatility.”
However, trends for sweetener substitutions are dependent more on blending than relying on just one sweetener. Other ingredients that achieve some of the properties of sugar are maltodextrin and also sugar alcohols, which act as humectants and are less cariogenic.
The challenge is not in finding equivalents, explains Leslie Skarra, president and owner of Merlin Development Inc. (Plymouth, Minn.), a contract food R&D company. Because each system is different, the challenge is obtaining the skill set to understand exactly what is happening in the food system. As an example, some of the functions of polyols and polydextrose are similar to sugar. Unfortunately, sugar alcohols have a laxative effect, which make them impractical for replacing large amounts of sugar. Polydextrose also can have that effect at levels above 15g per serving. “You can use more, but you have to label it as having a laxative effect,” explains Zammer.
Where's the Water?
Everybody has their eye on incorporating fiber into their formulas, which is a nice alternative to carbohydrates. However, water-insoluble fibers from fruits, beans, and seeds interact differently than water-soluble fibers originating from sources such as whole grain products, among others.Formulators need to understand exactly what the role of water is in regards to dietary fiber (whether the fiber is soluble, insoluble or colloidal), instructs Skarra. For each step during manufacturing, they should ask where the water is, what is holding it, what is not holding it, what is soluble and how it behaves at certain points in the system.
Most of the fibers diluted with water—such as oat and bamboo fiber—had a gritty mouthfeel, says Moles regarding her quest to reduce the carbohydrates for a low-carb cheesecake. “I didn't use any of those.” If you're replacing carbohydrates with fibers or proteins and they take up water in different amounts or at different times during processing, it will interfere with mixing or with how the food is formed in the initial wet state, says Skarra.
Zammer agrees, explaining that some proteins or fibers may absorb a lot of water and make it too thick. Too much water can also affect the microbiological stability or the water activity and shorten the duration of shelflife. “If you are adding more fiber to your product you can't just throw it in; there is a lot of extra formulation that goes along with it to make sure it is safe and palatable,” cautions Zammer.
Non-digestible hydrocolloids are examples of suitable starch replacements that help control moisture in soluble and non-soluble applications ranging from pie fillings to processed meats. However, these, too, can cause problems with dried particle dispersion. Zammer points to polyols and humectants like glycerin, which provide hygroscopic properties, to bind water to reduce growth of mold and assist in the dispersion of hydrocolloids.
“Some gums can be considered dietary fiber,” adds Zammer. “Gum arabic, which doesn't thicken too much, has a good mouthfeel, gives stabilization and emulsification properties and it doesn't contribute to 'net carbs.'” Polydextrose is also a fiber and can be labeled as such. Others fibers such as soy fiber or wheat fiber are useful if formulators are making a baked good and need ingredients with similar properties to wheat starch or flour.
Digestion-resistive starches, which have many of the properties of the traditional starches, but do not contribute to “net carbs” are increasingly being used in low-carb products.
Formulators are also recognizing the virtues of one of dietary fiber's best-kept secrets, flax seed, and are rushing in mass to suppliers who might fulfill their needs. Originally popular in pet food and animal feed, flax seed is making its way into the American palate. Dan Best, a marketing director for a flax seed ingredient supplier, suggests that flax seed can be used as a replacement for corn meal. “Deep fried products are 15-25% breading. That's a lot of carbs to cut,” says Best. “We can replace more than half of the breading with flax seed which, when milled, makes a nice flour and a pretty nice coating.” Additionally, flax seed is a source of alpha linolenic acid (ALA), a polyunsaturated omega-3 fatty acid.
Adding to the Team
Not all emerging ingredients cause processing problems. For instance, lutein, an antioxidant, which reduces the risk of age-related macular degeneration and may improve skin health, is user-friendly and heat-stable. This carotenoid is found naturally in dark green leafy vegetables, corn and egg yolks. It can be added into existing processing without having to make modifications. “The addition of lutein does not have a negative effect on other ingredients, and the other ingredients do not impact lutein,” says Linda Fullmer, group manager for research and development for a lutein supplier. “You don't have to add additional stabilizers or antioxidants.”The manner by which the food will be processed makes a difference in determining which foods are capable of supporting a new formulation. For example, omega-3 fatty acids are not well suited for extended duration, high-heat applications like fried foods, warns Hernandez. The nutritional benefits of omega-3s will keep them in demand for some applications, but they are impractical in others, as omega-3s can significantly decrease shelflife. In fact, some companies “try to minimize omega-3s in frying oils through blending or partial hydrogenation,” explains Hernandez.
The majority of products containing omega-3 fats continues to fall into the realm of nutritional supplements. Shelflife aside, fish odor and oxidative taste caused by polyunsaturated omega fats also hinder product functionality. Nevertheless, many formulators are steadily advancing the use of omega-3s in processed foods by inventing techniques that make the ingredient more acceptable.
For example, since most omega-3 is harvested from fish, some companies deodorize the oil by subjecting the product to very high heat in high vacuums to get rid of fish smells and taste. Other sources of omega-3 include fermentation technology.
Microencapsulation is a specialized technique that inhibits oxidation. Some manufacturers reduce omega oil interaction with oxygen by blanketing their tanks with nitrogen, an inert gas that does not oxidize the oils during mixing, and deters residual oxygen from getting in.
However, Zammer informs manufacturers they do not have to change their whole plant around or invest in complicated new technologies and equipment to get rid of the fish flavor and smell of omega-3 products. “By thinking about the order of addition and the way you handle the formulation as it goes through processing, you can make a big difference on product performance.” She suggests manufacturers optimize their processes in order to minimize omega oil contact with minerals, light, oxygen or any element that causes oxidation and, hence, the “fishy” attributes.
Since many products end up sitting for hours in tanks, Zammer recommends “waiting until the last possible second” before adding fish oils. For instance, waiting to add oils or vitamins/minerals until after homogenization or emulsification will make a big difference in flavor, but care needs to be taken to ensure they are well-dispersed in the product before packaging.
Depending on the temperature and finished product specifications, companies can add antioxidants such as vitamin E (tocopherol), BHT (butylated hydroxytoluene), BHA (butylated hydroxyanisole), or other natural and synthetic antioxidants to reduce the oxidation of omega-3 oils.
Hernandez suggests that formulation is mostly an empirical process paved by trial and error. Ignoring this concept has caused many formulators to fumble, especially when the product involves the addition of new ingredients.
“Traditional bakery skills, which keep high speed bakeries running very effectively, aren't sufficient to deal with the problems that come when you begin to substitute aqueous ingredients with non-aqueous ingredients,” says Skarra. Formulators must search beyond the resources they routinely use. “If they apply [just] those same skills, they may well fail.”
