Stevia® (steviol glycoside). A substance 200 times sweeter than sugar, it is extracted from the leaves of the Stevia rebaudiana (a plant originating in South America where it has been in use for some time for its sweetening properties). The good marketing launch of Stevia® was able to make most consumers perceive this sweetener as natural and safe (as demonstrated in studies conducted via blogs and social networks). Stevia® is already present in numerous light or sugar free products, especially in North America, as well as in dairy and cheese products. It is used also in the production of sugarless chewing gum (which currently constitutes the majority of the market) which up to now had primarily used polyols like xylitol. Often however, for a correct formulation of sugar free chewing gum (and other both hard and soft candies as well), bulking agents must be added (often polyols) that give the right mass and consistency to the product. Steviol glycosides appear to be promising even for the production of sugar free or low calorie chocolate (and its derivative products). While chocolate-based products containing Stevia® did not exist in 2009 (a time when the relatively inexpensive maltitol was the leading sweetener for chocolate) currently it has a one third share of the market. Maltitol has a laxative effect in high doses as well and cannot be marketed as “natural” since it is produced from an industrial hydrogenation process. Stevia® can be used as a sweetener for chocolate but requires bulking agents (polyols, vegetable fibre or dextrin) which are required less when using sucrose. Steviol glycoside has the negative aspect that it has an aftertaste similar to liquorice and this make it inadequate for some applications or requires adding flavours or other substances to mask this taste. In the case of cacao and chocolate-based products, this masking is not necessary. On the positive side, Stevia® compared to polyols does not have a laxative effect if consumed in high quantities and therefore does not require a warning label. If Stevia® is then coupled with fibre used as a bulking agent, it could be claimed that the product is also healthy because of its high fibre content, further increasing the appeal of the product.
Concentrated fruit juices
Concentrated grape or apple juice extracts are starting to be used as sweeteners in products like jams and jellies with reduced sugar content, but also in candies and chocolate-based products. In reality, these extracts contain sucrose, fructose and other simple sugars, therefore they don’t guarantee on their own a low caloric content. A famous Italian food brand was fined a few months ago because the label on the product read “without added sugar” when in reality one of the ingredients was concentrated fruit juice. Nonetheless these fruit extracts are perceived by the consumer as natural sweeteners, which can further increase the flavour complexity of the product (for example with hints of honey or caramel). Other extracts of this type are sugar cane syrup, maple syrup, agave juice, and coconut palm sugar or monk fruit extract.
Sweetener mixes and bulking agents
To downplay the “defects” of the different sweeteners, it’s possible to use a sweetener mix formulated to obtain the final desired outcome. For example the combination of isomalt-aspartame or the more recent isomalt- Stevia® is used for hard candy, while for soft candy there’s an innovative combination of vegetable fibre coupled with intense sweetener, as we shall explore. In some cases the replacement of sucrose with an intense sweetener creates a void in the product, like in both hard and soft candy, where sugar functions not only to sweeten but also makes up the majority of the mass of the product. Often polyols are chosen since they contain fewer calories than sugar but have similar physical, chemical and rheological characteristics. One limiting factor that they have, as previously mentioned, is the laxative effect. So how then can bulk be added to the product? Oligosaccharides can be used such as inulin (a food fibre which has prebiotic effects), or oligofructose, both of which are chicory root extracts with a slightly sweet taste. These substances, indicated on the label as polyfructose, fructo-oligosaccharides, chicory root fibre or chicory root extract, are well-suited to the market needs for a clean label.
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3. Martinex-Cerbera S., Salvador A., Sanz T. 2014. Comparison of different polyols as total sucrose replacers in muffins: Thermal, rheological, texture and acceptability properties. Journal of Food Hydrocolloids, 35:1-8
By Rita Lorenzini