Teaming fructo-oligosaccharides (FOS) with high-intensity sweeteners yields a sweetness profile closer to sugar, and with the added benefit of housing half the calories of sugar. And that doesn't even begin to address the FOS prebiotic properties. Joseph O'Neill explores this new option for reduced-sugar formulations

Sugar consumption continues to rise in the US despite medical and governmental warnings to reduce and/or minimise sugar intake. Excessive sugar consumption is a major factor in the development of adult-onset diabetes. These diseases, along with the many other health problems associated with the rising incidence of obesity in the US and in Europe, are major concerns from a public-health perspective.

Chicory root is one of hte main natural sources of inulinIt's a set of problems to which the processed food and beverages industries have been linked to. With the rise of healthier and formulations-friendly next-generation ingredients, and with consumer awareness helping to lead the way, solutions are readily at hand. The food industry has long recog-nised the opportunity for formulating low-calorie, low-carbohydrate, sugar-free and fat-free foods to address the consumer demand for products to help fight the battle against obesity and numerous diet-related diseases. Today, virtually every consumer recognises the need for balanced nutrition. Almost everyone is interested, to one degree or another, in reduced-calorie, fibre-enriched, sugar-free and reduced-sugar foods and beverages — especially when those products can taste good and still offer ready-to-eat convenience, as they support a healthy lifestyle.

When it comes to reducing or eliminating the sugar content in foods, formulators today have a variety of high-intensity sweetener (HIS) options available. The main HISs, used singly or in combination, include aspartame, acesulfame-K and sucralose. In spite of their clear self-interest, consumers are still relatively unwilling to sacrifice taste or texture, so the main challenge from a formulating perspective is to mask off flavours, or off notes, associated with HISs.

A new HIS option
A growing number of product developers have found a good solution by using a fructo-oligosaccharide (FOS), namely inulin or oligofructose, in combination with one or more HISs. Not only do inulin and oligofructose contribute partial sweetness, they offer a 50 per cent reduction in calories compared to sugar, as well as prebiotic benefits, and they have the ability to mask off flavours/off notes associated with the HISs. Sucralose, for example, is known to have a slight licorice off note, which can be masked by the addition of oligofructose.

Inulin is a polydisperse molecule found in many common fruits and vegetables, and can be readily extracted from chicory roots. The extract offers bulking properties similar to sugar, and can be differentiated based on chain-length distribution. Short-chain oligofructose has a degree of polymerisation of less than 10 and is available in both a powder and liquid form. Oligofructose syrups have a sweetness level 30-50 per cent of sugar. Native standard inulin has a degree of sweetness of 10 per cent of sugar.

Obviously, the sweetness level of sugar cannot be achieved by using inulin or oligofructose alone. Oligofructose and inulin need HISs to achieve the sweetness of sugar, while HISs need FOS to achieve an overall flavour profile closer to that of sugar. The flavour-masking benefits of chicory inulin and oligofructose can also be used to remove the off flavour or aftertaste associated with vitamin-enriched formulations and soy-based recipes.

An added benefit of using chicory oligofructose or chicory inulin is its capacity as a flavour potentiator. Both increase the perceived intensity of berry or fruit flavours in a formulation, for instance. The technical properties of a product like Orafti-brand oligofructose, as an example, make it an excellent substitute for sugar. In addition to helping to mask the off notes and aftertastes of HISs for a more sugarlike sweetness profile, Orafti oligofructose has similar sensorial and physical properties to sugar. It improves body and mouthfeel compared to traditional low-calorie fruit preparations based on HISs only, imparting a well-balanced and rounded fruit taste. In fact, it offers a better flavour release compared even to traditional sucrose-based formulations. Meanwhile, a specialised product like Orafti HSI (inulin) combines the technical and sensorial properties of both oligofructose and inulin, resulting in an optimized sweetness profile in combination with HISs.

A blend of acesulfame-K and aspartame with inulin or oligofructose results in a quantitative synergistic sweetening effect corresponding to 15-35 per cent more sweetness, depending on application and formulation. Synergies are also obtainable in yoghurts, for example, using a combination of oligofructose with sucralose or with sucralose/acesulfame K.

When selecting a specific inulin or oligofructose ingredient, practical considerations include:

  • Form — There is a choice of powder or liquid forms. Inulin is only available in a powder form whereas oligofructose is available as a powder and as a syrup.
  • Colour — Browning reactions occur readily with oligofructose because of high concentrations of reducing ends. The longer-chain-length inulin has minimal to no browning reaction during heat processing.
  • Flavour-masking benefits — the synergistic effect with high-intensity sweeteners
  • Chain-length distribution — important for mouthfeel characteristics/solubility
  • Particle size/density — important for dispersion
  • Desired sweetness level — of the final product

It is notable that when food and beverage formulators make use of all-natural inulin and oligofructose in combination with HISs, they add prebiotic fibre to the mix as well as replacing sugar and improving taste. That implies an extra measure of food-borne defense against obesity and diabetes, along with numerous other digestive disorders that dietary fibre, in general, impacts in a positive way.

In addition, clinical studies have linked inulin and oligofructose, as prebiotics, to a range of whole-body benefits that extend over a lifetime. By boosting levels of beneficial bifidobacteria in the colon, they can enhance digestive health, function and immunity, and exert positive effects on bone health through improved calcium absorption. They also help maintain healthy body weight in both adolescents and adults. They can increase intestinal levels of bifidobacteria in older people as well, helping to reverse signs of 'digestive ageing,' improving intestinal function while supporting wellness.

That kind of functionality, along with messaging about great taste, reduced sugar, reduced calorie, fibre enrichment and diabetic friendliness, brings into play the substantial marketing benefits of FOS/HIS combinations — a synergy that is truly hard to beat.

Joseph O'Neill is executive vice president of sales and marketing for Beneo-Orafti in North America (www.beneo-orafti.com). He holds a BS in Biochemistry and MS in Industrial Microbiology.
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