What makes a successful pairing? That combination of two elements where one brings attributes the other does not possess. Thus, the pair can work together collectively to give the best possible outcome. Sounds simple, right? Not necessarily so. Take a successful food combination like strawberries & cream; the fresh sweetness of the fruit is enhanced by the rich, luxurious mouthfeel of the cream. However, if you ate them separately, the experience of taste and texture is very different. In a similar way, the combination of plant-derived natural sweeteners and fibres can help to strike the right balance between simple sweetness and mouthfeel for texture in sugar reduced recipes.
The steviol glycosides, extracted from the stevia leaf, are the most widely accepted natural sweetener alternative to sugar. The glycosides are used in a variety of combinations to give a natural plant-derived sweetener with minimal calories, low glycaemic index and can be up to 400 times sweeter than sucrose. From a manufacturing perspective, stevia has many advantages as it is stable to extremes of light, pH, temperature and has good solubility properties. From 2010 to 2017, the % of global launches using aspartame fell by 16% whilst launches with stevia increased by 18% (source Mintel GDNP). This evidence shows stevia is fast becoming the choice of natural sweetener replacement for artificial sweeteners like aspartame, in response to growing consumer demand.
Inulin (or chicory root fibre) is a recognised dietary fibre that offers up to 60% sweetness (relative to sucrose). It is obtained from a natural plant source and can replace sugar in a variety of sweet and savoury applications. It provides a low calorific value and glycaemic index but it also gives mouthfeel for bulk sugar replacement. Replacement of sugar within recipes presents two challenges; the loss of sweetness and lack of mouthfeel. On its own, stevia will add sweetness but not bulk. However, if you combine stevia with inulin, you get the benefit of bulk to give mouthfeel which enhances sweetness whilst also suppressing the bitter/liquorice aftertaste associated with stevia.
However, the environment of a successful pairing is always important. Strawberries & cream on a sunny day at Wimbledon works beautifully. Offer the same combination at rugby match on a cold rainy night and you’ll get a different response! In the same way, processing conditions for ingredients are essential to their functionality. For example, inulin can break down under low pH conditions giving a gradual increase in sweetness over life which is why it is not suitable for sugar reduction in acidic beverages. On the other hand, current EU legislation does not permit the use of stevia in baked products but you can add it to post-bake additions like buttercream filling or chocolate topping. Flavours derived from stevia can be added pre-bake and declared as “natural flavour”, provided they do not exceed the maximum permissible dosage level. So, be aware that the synergy between stevia and inulin is not suitable for every single food category.
A report by the WHO stated that Unilever made a commitment to reduce sugar in its sweetened tea beverages by 25% by 2020. Between 2010 and 2016, they reported a 12% reduction had been achieved using stevia (steviol glycosides) as a natural sweetener. Since 2015, Heinz has used stevia in their formulation for lower sugar tomato ketchup. These are examples of stevia working with sugar to support recipes where the reduction needs to be done gradually or total replacement is not feasible. When using stevia in a supporting role, it is important to remember that it does not have the same temporal profile or linear response dose curve as sugar. Different variants of stevia offer changes in delayed onset and lingering of sweetness. As stevia is a combination of glycosides, it is crucial to choose the right variant for the application and start with a low dosage, so it has greater potency to show its synergy with sugar.
Some good examples of inulin and stevia working together can be found in low calorie or sugar reduced ice creams. Longer chain inulin gives added bulk for fat replacement with minimal impact on energy density, as it has half the calories of sucrose. Often it can be split with addition of a shorter chain inulin for sweetness but adding stevia enhances sweetness of flavours in the ice cream, to the extent that it may be possible to slightly reduce levels of any added natural flavours (if present). The ratio of inulin to stevia will depend on the desired texture of the finished ice cream (hard or soft) as well as the impact on freezing point depression and the size of ice crystals. The addition of short chain inulin to ice cream increases the amount of dissolved solids and lowers the freezing point. An ice cream with a higher content of dissolved solids has less frozen water and therefore gives ice cream with a softer eating texture.
Short chain inulin, with 50% relative sweetness, can be added with stevia to make no added sugar milk chocolate. The inulin provides the bulk to replace sugar and, as the stevia helps to optimize the sweetness profile, the inulin returns the favour by masking the strong bitter aftertaste originating from stevia. As a result, this helps retain the required mouthfeel for chocolate and masks any metallic/bitter flavour notes, as it melts in the mouth. When the inulin is used in powdered form, it means it can be processed in the same way as sugar is for regular milk chocolate, making it easier for manufacturers to adopt this ingredient with their processing equipment and methodology.
The partnership of inulin and stevia gives a natural, plant-derived sweetener combination that can be used across a range of categories. The picture is changing as manufacturers experiment with different ratios or variants of both ingredients to try and achieve their required level of sugar reduction. As we move past the initial 5-10% sugar reduction phase that most manufacturers are achieving through reducing pack size or taking down sugar and not adding anything, it will be important to discover more about this synergy and where else it can be applied. Remember, it is all about working together, right now, in sweet harmony!
Tayab Haq, Food Business Development Manager