Hydrocolloids: Gum control in a low-carb world

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.

Replacing sugar

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.

Replacing starches

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.

Taste enhancement

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.