Soluble dietary fibre – the multitalent polydextrose

Traditional ingredients such as sugar and fat are known to have a high energy content and are therefore the first things to be replaced in a calorie-reducing concept. Yet these ingredients give foods their taste, body and sensation and have important technological functions in the final product. If sugar or fat are replaced, for example, then a number of other substances need to stand in for them to maintain the quality of the end product or to allow low-calorie production in the first place.

Bulking agents such as polydextrose provide volume and body in the food and improve the sensation. They are used in many light products to replace fat and sugar, for example, and at the same time to make sure the consumer experiences the desired fullness and consistency.

Polydextrose is a highly branched, water-soluble polymer of randomly joined glucose units and has been long known as a filler and sugar/fat replacement in foods. Sta-lite III, the polydextrose from our partner Tate & Lyle, is produced by thermal polymerization of D-glucose in the presence of sorbitol and phosphoric acid.

Simple sugar and fat substitute

As a sugar substitute in foods, polydextrose is normally used in conjunction with strong sweeteners such as Sucralose. Sweeteners add sweetness to foods, but no volume. In these applications, polydextrose acts as a filler to replace the sugar volume essential to the recipe without adding many calories of its own. At the same time, it perfects the sensation.

Polydextrose has similar functional properties to the traditionally used carbohydrate sucrose (table sugar) and glucose syrup, and does a good job at replacing these in many applications. From a technological vantage, its ability to undergo caramelization and the Maillard reaction is crucial, as this adds flavour and aroma to the end product.

Compared to sugar, glucose syrup or starch, polydextrose has a low glycaemic index (GI) and is metabolized independently of insulin, meaning this substitute polymer is also suitable for diabetics. Furthermore, polydextrose creates a longer feeling of satiation. Replacing glucose syrup with polydextrose in chewing gums, hard and soft caramels and candies can reduce calories and make certain products suitable for diabetics.

Polydextrose allows the production of sugar-free, tooth-friendly and low-calorie sweets. In chocolate, polydextrose together with sweeteners replaces sugar, yet still lends the product a typical flavour. Polydextrose can help replace sugar in fruit spreads, sweet sauces, glazes and syrups as well. Polydextrose can replace both sugar and flour in baked goods and baking mixtures.

Again, it contributes to the development of flavour and colour while improving volume and crumb consistency. The slightly hygroscopic properties of the polymer have a positive effect on the shelf life of soft pastries. The product binds moisture and protects them against drying out. At the same time, it reduces frost damage such as freezer burn of deep-frozen dough and improves the stability of baked goods in freezing and thawing processes.

Polydextrose also helps reduce calories in glazes and frozen desserts. By lowering the freezing point, it reduces the formation of large ice crystals and contributes to creaminess and texture. Polydextrose has a favourable effect on moisture control in many different products.

Prebiotic properties as an added benefit

At an average degree of polymerization of around ten glucose molecules, Sta-Lite polydextrose by Tate & Lyle features many of the structural and physiological properties of soluble dietary fibre. The digestive enzymes in the mouth and upper gastrointestinal tract cannot break down polydextrose, which means it remains an energy source for microorganisms in the lower digestive tract.

Yet even there, polydextrose is only partially degraded so it has only a low percentage of the energy content of sugar or fat while simultaneously having the properties of soluble dietary fibre. Thanks to its high molecular stability, polydextrose can be used to act as dietary fibre in many kinds of products, including low pH drinks.

Furthermore, given the prebiotic characteristics of polydextrose and its low glycaemic index, a long-lasting satiation effect can be achieved, which in turn contributes to more efficient and effective weight Management.