In search of the perfect low-carb bar

The latest diet craze has forced the hand of product developers to create alternatives to carbohydrates that do not compromise on taste or functionality. From protein sources on one side to carb replacers like gums and fibres on the other, Todd Runestad investigates the options on the table

With low-carb consumers more label-savvy than ever, the trend has opened the doors of opportunity for innovative companies to showcase the latest ingredients and technologies in product development. A growing suite of protein options, carb replacer ingredients, ?better for you? fibre boosters and polyols are ensuring that even if the low-carb boom goes bust, a range of healthier functional ingredients will remain. Can the options currently available and those in the R&D pipeline create a best-case scenario on the bar front?

?No one ingredient is the magic bullet to take care of everything,? says Steve Young, PhD, product development consultant and North American technical adviser to Matsutani America. ?You use combinations of polyols, which might include maltitols and sorbitols, just like you would on the dietary fibre side and the protein side. By the same token, there are limits to each ingredient before the piece falls apart or gets mealy. Using a combination of ingredients is always the wisest play.?

The trick is figuring out how these ingredients work in a bar matrix. While most ingredients suppliers work with manufacturers of bars to develop solutions, not every new ingredient has been assayed and compared with every other functional ingredient.

Whey cool protein
?A challenge in formulating protein bars can be the drying effect and hardening during storage,? says Carolyn Podgurski, dairy ingredients specialist at the Dairy Products Technology Center at California Polytechnic State University and consultant with Dairy Management Inc. ?The complexity of substituting carbohydrates with dairy protein requires not only the addition of solids, but also replacing the functional properties of sugars and related ingredients.?

Dairy ingredients, in particular whey protein, can help on the high-protein side of the equation, she says. It does this by replacing carbohydrates, helping retain moisture, having a mild flavour and improving texture, all while extending shelf life. ?Whey proteins assist in reducing cooking and baking losses, improving yield, and increasing moisture and water retention in the baked good,? says Podgurski. Whey proteins have a high biological value — 104, compared to 100 for whole eggs, 74 for soy protein and 54 for wheat. They also contain a host of essential amino acids.

Soy protein
Soy protein isolates enjoy a special status as having a positive health perception on top of its general protein content. It is often blended with milk or whey proteins in bars, most prominently in Atkins bars. ?With recent technical advancements in the flavour and functional performance of soy protein ingredients from The Solae Co, consumer taste tests demonstrate taste parity to traditional milk proteins in many applications,? says Geri Burdack, nutritionist and director of communications for Solae, based in Missouri. ?The two biggest challenges are picking the correct protein for the specific application, and determining how to best incorporate the soy protein into the product.?

Soy enjoys a Food and Drug Administration-authorised health claim for heart health. In addition, the FDA is reviewing a petition to allow a health claim in reducing the risk of certain types of cancer including breast, colon and prostate.

Canola protein
Where soy protein can be extracted from soy meal using acids, that process destroys canola protein. A Winnipeg, Canada, company, Burcon NutraScience, has discovered a simpler way to do the job — dissolving the canola meal left after crushers extract the oil in salt water, then adding cold water to precipitate out a protein called Puratein. This has similar properties to egg yolk and could be used in protein bars, as well as applications in mayonnaise or as an emulsifier.

In addition, a second protein, Supertein, remains dissolved in the salty water. Burcon has entered a licensing agreement with ADM to commercialise the promising 90 per cent protein. Depending on regulatory approvals, the ingredient could hit the market in 2006.

Moving away from the positive-protein front to the minus-carb arena, a number of ingredients have been helpful in creating bars that house good organoleptic properties as well as fulfil the math of lowering the net carbohydrate intake. Whether marketers choose the term ?net carbs? or ?impact carbs? ? and of course without any official FDA definitions — these terms have been created to convey the idea that not all carbohydrates are to be bludgeoned equally.

Formulating with fibre brings up issues of viscosity and water retention. Gums are also used not only as binders but also as a fibre source; the only caveat with gums is they usually tie up a high amount of water in the application so they are limited in the amount that can be added.

Soluble dietary fibre can absorb water and help manage moisture
?Introducing Fibersol-2 preserves the fibre content and makes the piece more edible over the life of the bar. That is more so the case in soft cold-extruded bars than in baked bars because there?s a lot more moisture and they try to cram a lot more things in those cold extruded bars, particularly protein,? says Young of Matsutani, which produces the Fibersol-2 ingredient. ?By managing the amount and type of protein, and balancing it off with the dietary fibre source and working the size of the bar appropriately, you can make a softer piece across the entire shelf life expectations of the bar, and not be too concerned about the eating quality.?

Matsutani?s Fibersol-2 ingredient is a low-calorie fibre source categorised as a resistant maltodextrin in the US, a resistant dextrin in Europe and an indigestible dextrin in Japan.

Some carb-backers want consumers to buy into the idea of low Glycaemic Index foods, where foods with slowly digestible carbohydrates will have a low GI and will minimally raise blood sugar and insulin levels. This may help to prevent such health problems as weight gain, diabetes and heart disease. The net-carb equation is calculated by subtracting fibre and sugar alcohols from total carbohydrates.

?What you want to avoid are the fast carbs, meaning those simple carbs that cause a rush of blood sugar levels after a meal,? says Laurent Leduc, vice president of sales and marketing for Acatris, manufacturer of FenuLife, a soluble fibre. ?What FenuLife does is it binds to carboydrates and sugars during digestion and releases carbs on a slower pace.?

Replacing digestible carbohydrates from a product with dietary fibre, or non-digestible carbohydrates, is a solution that is catching on with companies offering a range of fibre solutions. However, formulators have to contend with issues regarding moisture retention and texture. Whereas insoluble fibre can dry out a bar, soluble dietary fibre can absorb water and help manage moisture.

?FenuLife is a soluble fibre so it?ll absorb moisture, which makes the bar crisp longer,? says Leduc. ?There are rice crisps or soy crisps that can benefit.?

The use of gum systems is one way to reduce net carbs while simultaneously boosting soluble dietary fibre levels. Although gums offer fibre content, they are not always seen by consumers as being bona-fide fibres — a concern for marketers.

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. All of the carbohydrates are derived from the fibre portion, giving gums a net carb load of 0g for the gum portion of a food item, something that starches and other products do not accomplish.

Gum acacia, traditionally known as gum arabic, comes through as an adhesive agent to hold bars together and give them form. It is a fibre-rich ingredient that can help replace the much-maligned high fructose corn syrup or regular corn syrup, brown rice syrup, or hydrolyzed gelatin.

?Arabic makes binding syrup and delivers soluble fibre as opposed to high fructose corn syrup, which brings in sugar and carbohydrate value,? says Gregory C Andon, business development manager for TIC Gums. ?Gums are also very effective in sugar alcohols. You can have very low water activity, which is important in nonbaked bars. A formulation with 75 per cent maltitol and 10 per cent gum arabic is extraordinarily thick and gives you as much viscosity as 60 per cent gum and water. That is where gums really come through in your standard nutritional bar formula.?

Like traditional syrups, gum acacia thins out when heated and thickens when it cools. Hence, it may perform similarly to a higher-carb corn syrup or maltodextrin.

Beyond replacing corn syrup, maltodextrin and other syrups, gum acacia can be used with other ingredients in low-carb products. Gum acacia mixes well with artificial sweeteners like Splenda or saccharine, as well as with proteins commonly found in low-carb, high-protein foods and beverages. Finding solutions to combinations of ingredients is keeping R&D departments on their toes to help marketers help consumers.

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