Given the complexities of ingredient interactions - not to mention consumer demands for products that are low in carbs yet still considered healthful and nutrient dense - formulating such products to replicate the taste, texture and appearance of traditional varieties is no small task.
The use of gum systems, which have been common food ingredients for decades, is one way to reduce net carbs while simultaneously boosting soluble dietary fiber levels. Hydrocolloids can be used to replace high-carb ingredients such as starch, flour, corn syrup and other ingredients, and work well with low-carb formulations for a number of reasons.
First, gums are technically considered carbohydrates and contribute to the total carbohydrate count of a food or beverage. However, they supply 85g of soluble dietary fibre per 100g on a dry weight basis, and all of the carbohydrates are derived from the fiber portion. This means that, according to low-carb diet plans, their net carb count can be reduced by an equal amount. This effectively translates into a net carb load of 0g for the gum portion of a food item, something that starches and other products do not accomplish.
Beyond not being included on any "do-not-eat" list of high-carb substances and containing important soluble dietary fibre, gums offer other health benefits. Among other functions, research has shown that gums can be utilised to support a healthy intestinal and digestive system and have been clinically proven to lower blood serum cholesterol. Guar gum and pectin, in fact, are specifically cited in Dr Robert Atkins? best-selling book New Diet Revolution as beneficial ingredients in the maintenance of a healthy cholesterol level.
In addition, gums are useful for low-carb products because of their versatility and availability. Derived from natural sources around the world and formulated into commercial forms by suppliers, they can be used as starch replacers for soups, sauces, dressings, dairy products, nutrition bars, functional beverages and some baked goods, among other items.
Sticking points: gum replacers
Gum acacia, also sometimes referred to as gum arabic, is one of the most commonly used hydrocolloids in the world. Harvested from the African acacia tree, it is currently being used in low-carb applications to partially replace corn syrup as a binder in various products, such as snack bars, energy bars, candy clusters, cookies and other similar products.
Gum acacia's low viscosity allows it to be prepared into a syrup at a high concentration. It is effective because, like traditional syrups, it thins out when heated and thickens when cooled. Hence, gum acacia may perform similarly to a higher-carb corn syrup or maltodextrin but features a different nutrient profile: The soluble dietary fiber level can be subtracted from a product's total carbohydrate listing.
In addition to mimicking the function of traditional high-carb syrups, gum acacia and similar gum systems (including gum acacia-based blends) are effective in low-carb formulations for other reasons. These hydrocolloids, for example, feature excellent binding and adhesive properties. The addition of gums also can impart a creamy mouthfeel and smooth texture for finished products like sauces, gravies, soups and dressings. For food service applications, gum systems offer exceptional freeze-thaw capability.
Because low-carb products may include other types of replacers and non-traditional ingredients, creating a proper mix of ingredients can be challenging. To that end, gum systems like gum acacia and gum acacia blends have been shown to mix well with artificial sweeteners like Splenda and saccharin, as well as with proteins commonly found in low-carb, high-protein foods and beverages.
In addition to gum acacia varieties, certain guar gum products also have been used effectively in low-carb formulations. Partially hydrolyzed guar gum, for instance, can be used at relatively high usage levels to boost the fiber content of a food or beverage without altering its viscosity or flavour profile. Currently, partially hydrolysed guar gum is being incorporated into low-carb soups and dressings sold to both food service operators and food processors.
As the low-carb market grows - and as formulators are busy satisfying new product demands - ingredients suppliers are increasingly providing solutions in the form of specialised gum blends with targeted applications. For example, new gum systems have been created for use in low-carb yogurts to help stabilise formulations, increase fibre content and ensure taste and mouthfeel. For low-carb and low-sugar ice creams, these gums provide a rich mouthfeel, texture and taste while increasing fiber levels and inhibiting quick meltdown. Even puddings are getting a ready-made low-carb solution, such as a new low-carb pudding base comprised of a carrageenan blend and other ingredients like polydextrose, salt, emulsifiers and a limited amount of bulking agents.
Which gum to use
As with most formulations, determining which gum to use in a particular low-carb application is a decision that depends on several factors. For items like yogurt, ice cream bases and puddings, a customized low-carb blend developed for that particular application would be a simple solution. The delivery system is often designed for ease of use for formulators; the low-carb pudding base, for instance, is available in a one-bag system, eliminating the need for up to a dozen separate ingredients.
Gums for use in low-carb applications, as with traditional food and beverage products, are typically available in powder form and can be incorporated in different ways. Application methods also differ. In nutritional bars, for example, the use of a gum acacia syrup at a 50 to 60 percent concentration to reduce the level of corn syrup is typically used to form a binding syrup that holds the bar together. The syrup is made and then applied to the rest of the ingredients of the nutritional bar in order to shape and cut the bar. Generally, the binding syrup comprises 15 to 25 percent of the weight of the bar.
Baked vs. non-baked goods
There are some differences between baked and non-baked products that the use of gum acacia can help solve. In baked products, the added water in a gum acacia syrup is driven off and does not affect the overall water activity level. In non-baked applications, a binding syrup based on water may result in too high a water activity in the finished product, because the excess water is never baked off. Since mold can grow at a water activity of 0.85 or higher, the excellent synergy between certain grades of gum acacia and sugar alcohols should be utilized - technology that applies both non-baked products and baked formulations.
Gum acacia syrup is also effective in nutrition bars for other reasons, including the type of sugar alcohols like maltitol, sorbitol, mannitol, xylitol and glycerine that are often used in such products. Thanks to hydrogen bonding, gum acacia will form a viscous syrup with both glycerine and maltitol, allowing for a lower gum concentration than in water, at levels of 10-32 percent.
Soups are another type of application for low-carb gum systems. In place of flour or other starches in a soup, a blend of bland-tasting guar gum and locust bean gum can be used in a base roux. Such a system is an effective replacer on a functional basis and also can be used at less than one quarter of the level of traditional starch or flour. This wasn?t possible in culinary products in the past because traditional guar gum delivered too much of a beany flavour. New technology has made this a viable option.
As for the future of the low-carb market, no one is sure where it is headed. Some observers believe such items may go the way of low-fat and low-cholesterol products if the marketplace becomes too saturated or if the diets prove hard to stick with among consumers. On the other hand, experts note that the popularity of low-carb diets has helped educate Americans about carbohydrate overloads in their daily diets and will likely result in a broader, more permanent shift in eating patterns. One thing is certain, however: Formulators and their suppliers will no doubt keep active to meet the sometimes fickle demands of consumers, whether it is the low-carb lifestyle or another food trend just around the corner. And that, to borrow a net carb term, is what really counts.
Gregory C. Andon is business development manager for TIC Gums Inc, headquartered in Belcamp, Md.