Polyfunctional Polydextrose

About 20 years ago, product designers feverishly working on fat replacement needed an ingredient to provide certain characteristics that went missing when fat was removed. They turned to polydextrose, and it was good. The next wave focused on sugar and carb replacement, and likewise on ingredients that mimicked sugars properties. They turned to polydextrose, and it was good. Today, product development concentrates on a host of health benefits. They still turn to polydextrose, and it is very good.

Tech specs

Chemically, polydextrose is a water-soluble, randomly bonded, branched carbohydrate polymer, with an average degree of polymerization of about 10 to 12 units and an average molecular weight of 2,000. It results from thermal polymerization of glucose; commercial forms are purified and sometimes undergo further reaction to modify their characteristics.

Polydextrose is classified as a digestion-resistant oligosaccharide. Molecularly, a-1,6 bonds predominate, but about 13% of the polymer has a-1,4 linkages, which can be hydrolyzed by enzymes in the human small intestine. Hydrolyzing these bonds produces lower-molecular-weight polydextrose polymers that pass through to the large intestine, where they are either fermented or excreted. Because it resists digestion, polydextrose has been determined to contribute 1 kcal per gram. This makes it an excellent bulking agent for a variety of reduced-calorie products, says Silvia Trimble, product manager, Tate & Lyle, Decatur, IL.

Nutritional benefits

Polydextrose also exhibits prebiotic activity; intestinal microflora partially ferment it in the large intestine. Numerous studies show it alters the short-chain-fatty-acid profile (the amounts of acetate, butyrate and isobutyrate produced by bacterial fermentation) and increases friendly Lactobacillus and Bifidobacterium species in the gut. The resulting short-chain fatty acids from the friendly bacteria generate an environment that retards colon-cancer development.

As a fiber, polydextrose supplies benefits provided by fiber intake and, in certain applications, developers might be able to achieve an excellent source claim, says Doris Dougherty, food scientist, Tate & Lyle. Soft-moist cookies work well, because high levels of polydextrose give a desirable texture.

Polydextrose helps with glycemic control with its low glycemic response, approximately 4 to 7, compared to glucoses 100. It nominally impacts glucose levels and insulin demand, making it suitable to replace high-glycemic carbohydrates, such as sugar, starches and maltodextrins. It can also promote satiety and aid weight loss or maintenance. This is a result of its low calories and ability to suppress appetite.

Functional finesse

Polydextrose has a clean flavor and neutral taste, and can help mask off-notes caused by vitamins, minerals, soy and other fortifying ingredients. It adds little sweetness, but can help balance the sweetness of sugar and high-potency sweeteners. However, it mimics many valuable characteristics of high-calorie carbohydrates, especially sugar. In baked goods and bars, it can add humectancy to improve texture and mouthfeel, and extends shelf life. Dissolved, it produces a Newtonian fluid with a higher viscosity than sucrose or sorbitol solutions at equivalent concentration and temperature, useful for sugar-free beverages. Polydextrose gives a freezing- point depression similar to sugar in ice cream and other frozen products.

Polydextrose is usually used for a combination of things, says Donna Brooks, regional director, Danisco Texturants and Sweeteners, Elmsford, NY, calorie reduction, sugar reduction all the things we talk about. Then its other qualities come into play, like digestive toleration, cost and availability.

A wide variety of applications, such as nutrition bars, cereal, baked goods, dairy products, beverages, fruit spreads and fillings, chocolates, confections and frozen desserts, and many others, have taken advantage of polydextroses functional and nutritional features. FDA recently expanded its approval, allowing its use as a bulking agent, formulation aid, humectant and texturizer in all foods except meat, poultry, baby foods and infant formulas (Title 21, Code of Federal Regulations, Part 172, Section 841). As a result, the biggest potential areas for growth would be yogurt, beverages, crackers and cereals, says Brooks, particularly yogurt, where we had no approval before. Especially since its a prebiotic and fi- berit just makes sense.

Because its functionality is so close to sugar, says Dougherty, in a beverage it gives body and texture. And in baked goods, it causes the flour starch to gelatinize at approximately the same temperature as sucroseyou can easily use it to replace sugar. She explains that, due to its gelatinization effects, polydextrose allows cookies to maintain the spread, and other products to maintain the texture, achieved with sugarsomething not easily done with other bulking agents.

Polydextrose is often used in confectionery products. It is an amorphous productit is not going to crystallize, so that needs to be taken into consideration, Dougherty advises. While that precludes it from nougats and fondant-based products, it is highly suitable for many other candies, including chocolate and compound coatings. In caramels it can give you a nice, desirable, long texture, she says.

One step beyond

Polydextroses multifaceted benefits open up new product areas. For example, Danisco has developed strawberry yogurtfilled confections and vanilla wafers that contain a probiotic culture and its prebiotics, polydextrose and lactitol, to create a symbiotic effect with digestive health benefits. These prototypes display a convenient, portable option for adding beneficial cultures and fiber to the diet, retain their benefits at room temperature for six months, and are ideal for chocolate bars, coatings, fillings, nutrition bar chips, and as inclusions in cereal and ice cream.

Even more surprising, Brooks notes, is that Litesse polydextrose is being used in beer in Japanso-called third beersas well as in some Happoshu, or second beers. These beers are reduced in sugar and/or malt, and the Litesse serves several functionalities, she says. It increases body and mouthfeel lost when removing the sugar and/or malt. It also increases foam stability, maintaining the foam head for a longer period, as well as increasing desirable lacing on the glass, all while allowing fiber and reduced-sugar and -calorie claims.