Texture Without the Calories

All signs indicate Americans are tired of identifying bad carbs and watching fat grams. They are returning to the basics of dieting: monitoring caloric intake. This signals an increased need for products that deliver the original eating experience without the calories.

There are two approaches most formulators take when attempting to lower the calorie content of a food and beverages, says Susan Gurkin, bakery category manager and technical applications manager, Cargill Texturizing Solutions, Minneapolis. They will often remove sugars and replace them with alternative sweeteners, or remove fats and replace them with water, or a combination of both.

Sugar provides four calories per gram; fat provides nine. But removing the fat and sugar is not a simple proposition, especially when it comes to maintaining a high-quality texture in the finished product.

Maintaining mouthfeel

Food formulators know all too well that sugar and fat provide most of the palate-pleasing textures Americans crave, as well as excessive calories. Their removal or reduction requires the addition of myriad ingredients that assist in recovering the rich texture synonymous with calories.

Sugars and fats play a very important role in the consistency and flavor of food products, says Aida Prenzno, laboratory director, Gum Technology Corporation, Tucson, AZ. The first step in developing low-calorie products is to find the right set of food additives that will mimic the mouthfeel of the original product without adding extra calories.

Gurkin explains that a products mouthfeel relates to the products physical and chemical interaction in the mouth. The ingredients in the formulation determine the structural and sensory characteristics of the product, and texture will change when any of the key components change.

Helpful hydrocolloids

Hydrocolloids are one of a food-product designers most-valuable texture tools, as they can improve mouthfeel and lubricity, manage water content, emulsify beverages, build viscosity, contribute elasticity, and extend shelf life by improving finished-product stability. Because they are used at very low levels in most formulationsalthough as carbohydrates they follow the 4-calories-per-gram rulethey contribute virtually no calories to the final product.

Gums do a great job of mimicking fat when hydrated, which allows for the removal of fat in various food systems without compromising texture and mouthfeel. The end result can be a lower-calorie food, says Mark Purpura, senior food scientist, Advanced Food Systems, Somerset, NJ. Gums can be used alone or in synergistic combinations.

Designing healthier dairy

For example, Advanced Food Systems offers a proprietary blend of milk and cream powders, starches, gums and flavors that replaces dairy cream. We have a system to replace heavy cream and a different one to replace half-and-half, says Purpura. The ingredients provide all the taste, texture, color and mouthfeel of their real liquid counterparts, just without all of the fat and calories. The ingredient is available in powder form, making it convenient for distribution and warehousing purposes.

Applications include everything from pumpable cream-style bakery fillings for low-calorie éclairs, to creamy soups and salad dressings. It can be used for a total or partial replacement of dairy cream, says Purpura. Partial replacement allows marketers to still make a made with real dairy claim.

The company has developed a proprietary dry blend of hydrocolloids that hydrates in milk, resulting in a product that resembles heavy cream. According to Purpura, using the ingredient in nonfat milk instead of heavy cream can cut the fat of some applications by 70%. This, in turn, provides a significant reduction in calories without sacrificing that dairy creaminess consumers crave.

Gum Technology offers a similar line of milkfat substitutes. Its dairy-fat replacer contains cellulose gel, konjac gum, sodium alginate and xanthan gum. The alginate reacts with the calcium present in milk to form a gel network, says Prenzno. The cellulose gel and the xanthan help introduce air to create a rich and creamy product with excellent overrun. It can be used at a rate of 0.2% to 0.5% to replace the milkfat in mousse-type products. Such dairy desserts are typically based on heavy cream and are calorically dense. Replacing some of the cream with a hydrocolloid system lowers calorie and fat content.

Ice cream is another product that traditionally relies on a high-fat content for texture. In ice creams, reducing sugars or fats will increase the freezing point and, therefore, create a harder consistency, says Prenzno. Gums help to bind the moisture and control the ice-crystal size, stabilize the product during freeze/thaw cycles, and add creamy texture and suspension.

Better-for-you baked goods

The dairy-fat replacer also allows for replacement of up to half the fat in some bakery products without impacting the structural integrity or sacrificing the desired high-fat mouthfeel, explains Prenzno. Depending on the application, usage levels range from 0.l% to 0.5%.

Konjac gum plays an important role. Many in the hydrocolloid business believe that konjac is underutilized in the food and beverage industries.

Years ago, there were quality issues associated with konjac, but todays processing of this highly concentrated glucomannan makes it an ideal hydrocolloid for many low-calorie formulations, says Alan Harpell, senior research scientist, FMC BioPolymer, Philadelphia. Konjac is highly viscous; it works in synergy with other gums and is thermally stable if treated correctly.

FMC developed lite chocolate cake made with konjac flour. The konjac allows for a fat reduction from 14% to 5% fat, yet still allows for uniform air-cell structure and freeze/thaw stability, says Harpell. This ingredient also includes xanthan gum. Together, they allow for up to a 65% fat reduction, and an accompanying reduction in calories, while maintaining desirable eating qualities, flavor and slicing properties. A 35-gram serving of the prototype cake contains 90 calories, 1.7 grams fat and 14.6 grams carbohydrates. The same-size serving of traditional chocolate cake has 130 calories, 5.0 grams fat and 21.0 grams carbs.

TIC Gums, Belcamp, MD, offers a solution to lowering calories in baked goods such as muffins, biscuits and other cakelike products by cutting about 15% of the fat out of the formula and replacing it with a flavorless, colorless gum blend. The combination of cellulose, guar and xanthan helps retain moisture and lubricity, says Jeremy Higley, food scientist, TIC Gums.

In low-calorie baked goods, gums will add structure and bind the moisture in the system, allowing for a longer shelf life, says Prenzno. In products that get frozen, they will help with freeze/thaw stability. Gums will also add pliability to any type of dough and can add suspension in cake batters. The latter allows for even and consistent distribution of ingredients such as chocolate chips, fruit pieces and nuts, just like a baker would experience when using butter or shortening.

De-lite-ful dressings

The mouthfeel of fats in dressings is substantialand it provides other qualities, too. All of these can be supplied by hydrocolloid systems.

In low-calorie dressings, gums will provide silky and creamy mouthfeel, says Prenzno. They will also add cling and suspension and improve the overall appearance of the system. She describes a proprietary stabilizer blend of gum arabic, xanthan gum and carrageenan as providing excellent texture in non-oil, low-sugar dressings, at use levels from 0.1% to 0.5%.

A next-generation emulsifier makes use of TIC Gums patented modified gum acacia technology to replace (on a one-to-one basis) more-expensive propylene glycol alginate (PGA) in a variety of applications, including salad dressings and marinades. Like PGA, it will impart a creamy texture that mimics fat in low-fat dressings, says Higley.

Beyond effectiveness, availability and cost, the ingredient allows for easy dispersion and rapid hydration, because it has been agglomerated using our Pre-Hydrated process, says Maureen Akins, lead food scientist, TIC Gums. On its own or in combination with other ingredients, it can eliminate extra processing steps like slurry-in-oil methods.

Higley says there are three grades of the emulsifier: one for full-fat formulations, another for reduced-fat and fat-free systems and one for highly viscous systems such as spoonable dressings and mayonnaise. In reduced-fat dressings, the emulsifier provides creaminess, smooth mouthfeel and particle suspension, he says. Further, it keeps calories low and herbs and spices in suspension. When poured onto lettuce leaves, it provides for excellent cling.

Cellulose gel is also effective when it comes to replacing fat and lowering calories in cream-style dressings, explains Donna Pechillo, senior research chemist, FMC BioPolymer. The cellulose gel creates a colloidal dispersion that structures water and imparts physical stabilization in aqueous systems, she says. The dispersion stimulates the rheological properties of fat, imparting body and creamy mouthfeel to water-based dressings.

Varying the level of cellulose gel, or using it in combination with other ingredients, allows for the development of different textures and mouthfeel, Pechillo continues. Levels also vary based on the degree of fat reduction. For example, a creamy dressing can drop from 140 calories and 14 grams of fat per serving to being light at 38 calories and 4 grams of fat with the addition of 1.25% of the cellulose gel, she says. The dressing can be fat free when the usage level is 2.0%.

If the dressing is clear, such as vinaigrette, iota carrageenan assists with replacing oil and keeping herbs and spices in suspension. It is also considered all-natural and has application in refrigerated, spoonable dressings and dips, says Pechillo. Iota carrageenan provides lubricity as it replaces fat and reduces calories. It maintains that cut consumers expect from spoonable, premium dressings.

Stay sweet sans sugar

Replacing fat is one hurdle, but multifunctional sugar is another challenge, since besides the obviousproviding a sweet flavor profilesugar has many and varied roles in food and beverage applications. When sweet is the primary role of sugar, as in soft drinks, replacement is not as challenging as in other applications where sugar performs other critical functions.

In baked goods, yeast needs sugar to regulate the fermentation process causing bread to rise, says Gurkin. Sugar adds a smooth bulk to ice cream and imparts body to beverages. In nonsweet foods, such as salad dressings, sugar enhances the flavor and balances some of the natural acidity present.

Sugar replacers are grouped into two categories: no- and low-calorie. Replacement or reduction with no-calorie sweeteners is more challenging in some applications than others. For example, consider the use of neotame in sweet baked goods. At about 8,000 times sweeter than sugar, neotame is the sweetest high-intensity sweetener approved for food and beverage use in the United States. If a baked application is 25% sugar, that 25% sugar can be replaced with a mere 0.0030 grams of neotame. Bulking ingredients are required to replace the solids removed with the sugar.

If going for a sugar-free claim, and no other ingredients contribute sugar (i.e., if milk or cream is added, the naturally present lactose prevents a sugar-free claim), 100% replacement of sugar is necessary. However, some baked-goods manufacturers have found that replacing some of the sugar with a high-intensity sweetener is the best approach to lowering calories and reducing sugar content. For example, the same formula can be modified to contain 50% less sugar by replacing 12.5 grams sugar with 0.0015 grams neotame. Replacing the almost 12.5 grams of solids in such an application might prove to be less challenging.

Microcrystalline cellulose (MCC) is very good at binding moisture and providing solids to no-sugar-added and low-sugar formulations, says Pechillo, adding that noncolloidal MCC is effective at replacing nonnutritive, caloric ingredients such as the basics in baked goods: flour and sugar. This MCC can be dry blended with other ingredients, she says. It has unique particle morphology that is rounded. It assists with interrupting the firm texture that develops when sugar and fat are removed from formulizations.

Solids replacement is an important consideration in many no-sugar-added beverages formulated with high-intensity sweeteners, since solids provide mouthfeel. For example, to provide milks nutritional benefits, but without all the calories of sugar-sweetened flavored milk, parents and schools have started viewing alternatively sweetened flavored milks as a viable option.

Whole milk is a nutritious beverage, offering consumers protein, calcium and other key nutrients. Unfortunately, it has a fatty-acid profile that concerns health- and-wellness-seeking demographic groups, says Harpell. Fat-free milk offers nutritional benefits without the fat content, but it is considered to have a watery mouthfeel, lacking in flavor and an unattractive appearance. Take the sugar out of flavored fat-free milk, and formulators are faced with an even greater challenge.

A cellulose gel and carrageenan blend can address the issues in fat-free, no-sugar-added flavored milk, continues Harpell. This combination of ingredients improves texture; imparts a mouthfeel and body similar to higher-fat, sugar-sweetened milks; produces smooth flow characteristics; provides clean flavor release; and enhances visual appearance.

Prenzno adds: In low-calorie beverages, gums will provide a smooth consistency and excellent flow. Blends of hydrocolloids such as carrageenan, xanthan and tara gums, and cellulose gel are great choices for sugar-free, nonfat smoothies.

Bulking up sweetness

Low-calorie alternative sweeteners often minimize the solids-reduction issues, as usage levels are very similar to, or the same as, sugar. Many alternative sweeteners have added benefits associated with them. For example, tagatose, which has a physical bulk similar to sugar and is almost as sweet, contributes only 1.5 calories per gram, as compared to sugars 4. Tagatose is also metabolized differently. It has a minimal effect on blood glucose and insulin levels and provides a prebiotic effect.

Polyols, or sugar alcohols, are a category of alternative sweeteners that can help lower calories. These carbohydrates have a chemical structure that partially resembles a sugar and partially resembles an alcohol. They require their own line on the Nutrition Facts.

Polyols are incompletely absorbed and metabolized by the body and, consequently, contribute fewer calories than sugars, says Tim Bauer, polyols and dextrose product line manager, Cargill North America. Due to their incomplete absorption, polyols produce a lower glycemic response than sugar or glucose.

Sorbitol is the most commonly used and economic polyol, Bauer continues. It is about 60% as sweet as sugar with a third fewer calories, and very stable and chemically unreactive. Besides providing some sweetness and solids, sorbitol functions as a humectant and texturizing agent in snack foods and baked products. This helps maintain their initial freshness during storage.

The polyol isomalt is manufactured from sugar in a two-stage process where it is first transformed into isomaltulose and hydrogenated into isomalt. Humans can only use 50% of isomalt for energy; thus, isolmalt provides 2 calories per gram. Its very low hygroscopicity allows it to fully replace sugar in a one-to-one ratio in many applications, including some baked goods.

Erythritol is gaining a great deal of attention in the low-calorie-formulating movement,because it is considered all natural, and thus accepted by the natural-foods industry. Organic erythritol is also available.

Erythritol has recently been recognized as providing zero calories per gram, says Bauer. It is rapidly absorbed in the small intestine and eliminated by the body within 24 hours.

This white crystalline powder flows easily due to its nonhygroscopic character. With about 70% the sweetness of sugar, erythritol has a clean, sweet taste, similar to sugar. Applications include beverages, crystallized confectionery, chocolate confections and dairy foods, including the increasingly popular category of yogurt beverages and shot-style probiotics.

Because of its reduced sweetness, as compared to sugar, erythritol is often used in combination with high-intensity sweeteners, says Bauer. It has been shown to work synergistically with aspartame and acesulfame potassium, resulting in a sweeter combination than the sum of the individual components, and with an improved taste profile, as well as economic and stability advantages.

Fiber solutions

Fiber is another ingredient that can make up for sugars bulk without adding high calories. Tate & Lyle, Decatur, IL, offers soluble corn fiber as a partial replacement for sweetener solids in low-calorie formulations. At 2 calories per gram, it reduces calories and adds fiber to an array of foods, even products where one would not expect to find fiber, such as sauces, dressings and clear beverages, explains Doris Dougherty, senior food scientist, Tate & Lyle.This prebiotic fiber has excellent process and acid stability, and dissolves clear in applications, she says. In addition to contributing fiber and reducing calories, it helps maintain the texture and body imparted from nutritive sweeteners.

Using the soluble corn fiber in combination with sucralose, we were able to develop a 50% juice drink that has one-third fewer calories than some of the 25% juice drinks in the marketplace, Dougherty continues. When the soluble corn fiber is added at a rate of 8.7%, the finished juice beverage contains 14 grams of prebiotic fiber per 8-oz. serving.

Fiber, in the form of a resistant starch, assists with lowering calories in fried snack foods. It has very low water-holding capacity, making it easy to substitute for wheat flour in low-moisture systems such as crackers, cookie and snack products. Dougherty says. Because it picks up less oil in fried foods, sometimes as much as 15% to 20% less oil, these foods contain less fat and, thus, fewer calories. Further, the low water-holding provides for quick-release of water during processing. This allows for the proper amount of puffing and crisping of the finished product.

Jim Miller, director of product management, Tate & Lyle Americas, says other resistant starches do not survive well in extreme process conditions. But, he says this particular ingredient can be used in smaller quantities to deliver better results. This means it is cost-efficient and has less impact on the formulation.

Labeled as corn starch on ingredient legends, the new resistant starch contains 1.7 calories per gram. It effectively replaces grain-based ingredients such as corn meal or wheat flour in an array of snack foods. For example, by directly replacing a portion of the corn meal in a corn-puff snack, the calories can be reduced up to 25%, at the same time allowing for an excellent source of fiber claim.

Polydextrose is another fiber-like ingredient that has a long history as a bulking agent for sugar as well as fat replacement. It is considered a digestion-resistant oligosaccharide, providing 1 kcal per gram, plus prebiotic qualities. It supplies little to no sweetness, making it a valuable sugar-replacement tool when combined with high-intensity sweeteners.

Food-product designers have an array of tools to assist with keeping calories low and flavors and textures satisfying. As consumers return to counting calories to lose and maintain a healthful weight, they will have plenty of delicious options to choose from.

Donna Berry, president of Chicago-based Dairy & Food Communications, Inc., a network of professionals in business-to-business technical and trade communications, has been writing about product development and marketing for 13 years. Prior to that, she worked for Kraft Foods in the natural-cheese division. She has a B.S. in Food Science from the University of Illinois in Urbana-Champaign. She can be reached at [email protected].