The growing demand for food products that not only control calories but also nourish and taste good has created newfound respect for gums and hydrocolloids among food formulators.
Made up of proteins or carbohydrates, these multifunctional ingredients compound with water (as their name suggests) to achieve their functionality and help resolve a myriad of formulation issues. Generally colorless and bland, gums and hydrocolloids are convenient and versatile solutions for sensory enhancement, calorie reduction, shelf-life extension and cost reduction.
Food formulators today are challenged to remove, reduce or replace a ingredients to create foods that go beyond the low-carb or trans-fat free demands resulting from emerging regulations, changing trends in nutrition and growing consumer awareness of what's healthful. But food reformulation entails much more than simply replacing an ingredient or two -- as one would when replacing raisins with cranberries in a granola mix. Developers must ensure the substitute ingredient matches the functional and nutritional requirements of the one that is being replaced without negatively impacting the taste of the original food product.
The anticipated sensory pleasure conveyed by the appearance and packaging may entice consumers to try foods for the first time, but taste constitutes the real seal of approval and the reason for repeat purchase.
The right gum for the job
"Starch, particularly modified starch, is the most widely used hydrocolloid in the food industry and accounts for more than three-fourths of total hydrocolloid use by volume," says Dennis Seisun, CEO of IMR International (www.hydrocolloid.com), San Diego. "Gelatin, a unique protein, ranks a distant second in this ingredient category made up predominantly of polysaccharides. Gelatins and starches account for more than 50 percent of hydrocolloid value in North America."
Sophisticated manufacturing has created a number of novel functional proteins and polysaccharides as part of tailored texturizing and stabilizing systems.
Why hydrocolloids are ideal
The unique and unifying characteristic of hydrocolloids is their ability to interact with water and form gels at very low concentrations. Gels are essentially three-dimensional interconnected molecular networks that exhibit varying degrees of strength, stability and ability to entrap water and manage its migration.
Another common characteristic of hydrocolloids is their tendency to form colloidal solutions. Distinctly different, colloidal solutions are relatively stable and generally viscous. In colloidal solutions the hydrocolloid particles retain a measurable size and may be separated from their dispersing solution by passing through a semi-permeable membrane.
The food industry has a wide range of hydrocolloids to choose from including agar, alginates, gum arabic, carrageenan, cassia, carboxy methyl cellulose, gelatin, gellan, guar, karaya, konjac flour, locust bean gum, methyl cellulose and hydroxypropyl methyl cellulose, microcrystalline cellulose, pectin, starch, tara, tragacanth and xanthan. They can be used alone or in tailored blends.
Selection of the hydrocolloid for a particular application depends largely on the functionality required and the processing parameters. Other considerations include ease-in-handling characteristics, versatility, interactions with other components, consumer acceptance on the label and, of course, price and availability.
There is a misconception that sugar replacement is a straightforward affair involving the simple substitution of glycemic sugar with a mixture of a high-intensity sweetener and a bulking agent. In reality, a number of diverse challenges are encountered during sugar substitution including the proper development of texture and stabilization.
Sweetness, although considered a "single dimension" of food product flavor, cannot be addressed merely with a sugar substitute. Sugar substitution entails the development of proper flavor profile - a particularly daunting task when the replacement involves a number of other carbohydrate ingredients besides sugar (as is necessary for creating low-carb foods). Hydrocolloids possess a range of properties that come in quite handy for many of these applications.
For example, when developing low-carb beverages, the ability of hydrocolloids to provide mouthfeel, viscosity, particle suspension and even emulsification helps create beverage products with smooth taste and without harsh spikes of sweetness or flavors. This functionality probably accounts for the quality and variety of low-carb beverages in the marketplace today.
Formulators typically employ high-intensity sweeteners such as aspartame, acesulfame K, sucralose and maltitol to replace sugar, and they incorporate hydrocolloids, such as carrageenan, gum arabic, guar, and xanthan, in small quantities to create the desired viscosity and texture. Pectin and carrageenan are the hydrocolloids of choice for dairy beverages while cellulose or carboxy methyl cellulose are preferred for thickening clear non-dairy beverages.
Sometimes, high-intensity sweeteners provide an overpowering sweetness, especially in diet beverages. Pepsico (www.pepsico.com), Purchase, N.Y., employed gum arabic in creating Pepsi Edge, a mid-carb and -calorie soda for people who wish to reduce their carb intake but don't like the taste of diet products.
TIC Gums (www.ticgums.com), Belcamp, Md., sensed market potential and recently rolled out TIC Pretested Ticaloid LC low-carb syrup replacer. Marketplace demands may escalate for similar lines of hydrocolloid mixtures to provide both texture and mellow sweetness in formulations in which high-fructose corn syrup is reduced or partially replaced with high-intensity sweeteners - especially if suspected connections between HFCS and obesity are borne out.
Hydrocolloids can gel efficiently and help thicken foods at a fraction of the cost of starch concentration. This functionality has been used effectively to reduce the carb content of gravies and savory sauces.
Low-carbers had to give up these foods because of their reliance on native or modified starches, which are glycemic and contribute sugar to the blood. The retail success of non-carb gravy thickeners -- such as ThickenThin not/Starch from Expert Foods (www.expertfoods.com), Ellicott City, Md. -- is evidence of how well a mixture of acacia, guar, carob, and xanthan works for low-carb cooking.
"We created not/Starch as a thickener for low-carb or grain-free diets to re-create the thick, rich textures one wants without adding calories, fat or carbs in gravies," says President Mark Uhrmacher. "Additionally, hydrocolloids contribute fiber that is so difficult to get on a restricted diet."
Processed foods use a range of modified starches to create textures and functionalities. The current focus on carbs and glycemic effects has compelled processors to explore the realm of hydrocolloids for healthier and less expensive replacements to reduce or remove starch from product formulations.
Although several resistant starches have emerged recently and grown significantly as alternatives for traditional starch ingredients, their price and varied glycemic implications have driven food formulators to hydrocolloids and blends as more consistent and less expensive non-glycemic alternatives.
Hydrocolloids may be used to partially replace starches to thicken medium- and high-solids systems such as fruit fillings and preserves. In conjunction with high-intensity sweeteners, hydrocolloids allow for the formulation of full-bodied, low-carb chocolate and other dessert sauces with enhanced flavor release.
"Other benefits include improved flavor and significantly reduced calorie contribution, since some hydrocolloids contribute no calories," says Nancy Mosier, food product formulator and author of "Eat Yourself Thin!" Mosier is a pioneer product formulator in the low-carb arena and has used hydrocolloids in combinations to allow for multiple functionalities.
Xanthan-guar systems help low-carb fruit preserves and pie fillings retain their texture and pourability through a wide range of temperatures, during both processing and serving, without sacrificing taste or appearance. Guar serves as the low-cost thickener while the higher priced xanthan modulates heat stability and rheological properties.
But carb replacement is not a slam-dunk affair. Removal of carbs poses a number of challenges that need to be addressed by food formulators. Fortunately, hydrocolloids have a plethora of functional properties and can help with texture modification, hydration, gelling, rheology modification, stabilization, emulsification and emulsion stabilization, suspension, thickening, fiber fortification, mouthfeel improvement, calorie reduction and fat replacement.
The focus on incorporating fiber to create low-carb foods has raised the profile of hydrocolloids as a healthful alternative to simple and glycemic carbs. Their characteristic colloidal interaction with water is unique for each kind of hydrocolloid and further depends on their source, chemical makeup, physical structure and even size. Simple alteration of various aspects of their physical properties has helped create a wide range of functionalities for processors.
"Gums are soluble dietary fiber, so they fit well into low-carb diet plans," says Frances Bowman, marketing manager at TIC Gums. "While hydrocolloids still contribute to the total carb count of a food, they help reduce the 'net carb count' by providing approximately 85g soluble dietary fiber per 100g with fiber accounting for all of the carb content."
"Beverages and soups offer excellent avenues for enhancing the dietary fiber intake of consumers -- especially for food companies wishing to capitalize on the new low-carb and fiber-hungry market segments," says John Foraker, president of Home Grown Natural Foods (www.homegrownnaturalfoods.com), Napa, Calif. With its twin brands of Fantastic Foods and Consorzio, the company did exactly that by incorporating hydrocolloids to roll out Carb'Tastic soups, a line of reduced-carb cup soups that have been wildly successful.
Is low-carb just a fad? While the flurry of new-product activity may be slowing, the legacy of the low-carb movement will be a greater awareness of healthier choices.
Consumers are actively removing simple carbs from their diets and consuming more fiber as a result. The future is promising indeed for the hydrocolloid industry.
Kantha Shelke is a principal at Corvus Blue LLC, a Chicago firm that specializes in competitive intelligence and expert witness services. The firm helps businesses and professional organizations in the health and wellness sector to focus on what matters most. Contact her at firstname.lastname@example.org or 312-951-5810.
|Hydrocolloid strategies for carb reduction|
Growth in sugar-free sweeteners, bulking agents and specialized texturizing agents has been fueled by the term "net carbs." The term was made popular by the marketing efforts of the Atkins Net Carbs Seal and denotes the number of grams of carbs that will convert rapidly to blood glucose.
Hydrocolloids play into carb reduction in a number of ways:
* Eliminating sugar -- Hydrocolloids can help replace the water-binding and bulking properties of sugar that has been removed to make low- and no-sugar foods. High-intensity sweeteners present new stabilization issues because they are typically used at low levels and generally leave water "unbound." A number of hydrocolloids can provide stabilization by inhibiting moisture migration and controlling syneresis.
* Replacing starch -- Native and modified food starches are becoming more popular because of the wide variety of functional properties they provide. Non-starch hydrocolloids offer versatile starch replacement solutions and can help retain shelf-life and texture characteristics without the variable glycemic effects and cost implications often associated with newer resistant starches.
* Enhancing dietary fiber -- Hydrocolloids do not typically contribute significant fiber because they are used at low levels and they serve mainly to control water. In low-carb formulations, however, low-viscosity hydrocolloids can be used in amounts sufficient to provide substantial levels of fiber. An added benefit comes from the ability of some hydrocolloids to delay gastric emptying. The resulting extension of the feeling of satiety can help reduce hunger and help reduce an individual's food intake.
* Enhancing taste -- A variety of ingredients -- including protein, high-intensity sweeteners and modified starches used to fill the void left by the removal or reduction of starch and natural (glycemic) sugars -- tend to bind flavor and often alter the taste of low-carb foods. Hydrocolloids are typically bland and serve as innocuous bulking agents that can also help reduce usage levels of added flavor ingredients.
"Hydrocolloids can be the perfect choice for low-carb product development as they not only improve product texture and stability, but also contribute dietary fiber and a low glycemic response," according to Jim Carr, hydrocolloid expert at Excelon Specialty Products Inc. (www.excelon-inc.com), Lake Bluff, Ill.