Professor Julian M Cooper reviews the multi-functionality of sugars and looks at the challenges that face the product developer trying to reduce or replace sugars in foods.
Reformulation is seen by many as the universal panacea for reducing sugars in foods and beverages, thus delivering healthier foods. Reformulation is identified as a key factor in HM Government’s Childhood Obesity plan , which proposes a broad, structured sugar reduction programme to remove sugar from the products that children eat most. The plan has challenged the food and drinks industry to reduce overall sugar across a range of products by at least 20% by 2020 . It quotes evidence that slowly changing the balance of ingredients in everyday products is a successful way to improve diets. Many other parties also advocate a stepwise reduction of sugar in products to deliver healthier food. Much of the evidence is based on successful reformulation of salt in a range of food products and it is assumed that sugar can be reduced/ replaced in the same manner. This paper explores the practicalities of this approach and evidence is provided to demonstrate that, in contrast to salt reformulation, a sugar reduction/ replacement strategy may not deliver the desired healthier benefits.
it is not possible analytically to distinguish between intrinsic and extrinsic (free or added) sugars.”
Sugar and sugars
Sugars are often referred to as sugar and sucrose (i.e. granulated sugar) is viewed as the only sugar present in food products. In fact, there are several sugars that can be present in foods, the most common are the monosaccharides glucose, fructose and galactose and the disaccharides sucrose, maltose and lactose. The occurrence, chemistry and the different ways that sugar can be defined have been reviewed in a recent Information Statement from IFST . Nutritional labels list all the mono and disaccharides present in a product from the ingredients and may include all the sugars mentioned above.
The Scientific Advisory Committee on Nutrition (the UK Government’s advisory group, commonly known as SACN) has recommended that the definition for ‘free sugars’ be adopted in the UK . Free sugars are defined as all monosaccharides and disaccharides added to foods by the manufacturer, cook or consumer, plus sugars naturally present in honey, syrups and unsweetened fruit juices. Under this definition lactose, when naturally present in milk and milk products, is excluded.
It should be noted that it is not possible analytically to distinguish between intrinsic and extrinsic (free or added) sugars and estimates are based on the best available information.
||Functionality delivered by sugars
||Sweetness, mouthfeel, flavour enhancement
||Sweetness bulk, preservative, humectancy, colour & flavour formation, solubility, flavour release, crystal and glass formation
||Sweetness, bulk, humectancy, colour & flavour formation, texture modification, coating, glazing, fermentation substrate
||Sweetness, mouthfeel, flavour enhancement
||Sweetness, bulk, colour & flavour formation, texture modification, structure forming, bowl life
|Jams & preserves
||Sweetness, bulk, flavour enhancement, colour & flavour formation, preservative, synergy with other ingredients
||Sweetness, bulk, flavour enhancement, freezing point depression, mouthfeel
Table 1. The functionality of sugars in food products 
Functionality of sugars
Sugars are not only sweet, they also deliver many and varied properties that are specific to different food products. They provide texture, mouthfeel, bulk, colour, flavour, preservative and humectancy. They also interact with the other ingredients present to deliver, for example, colour and flavour when processed (e.g. in cooking and baking). These different properties are summarised in Table 1. The mono and disaccharides deliver different properties, for example, sucrose is used as the standard for sweetness and has a value of 1 – the other sugars have different levels of sweetness and may also differ in sweetness quality. Together they may deliver sweetness synergy, delivering a higher level of sweetness than the individual sugars; this can be exploited in some products toreduce the amount of sugars used. A more detailed explanation of the functionality of sugars is provided in the IFST Sugars Information Statement .
In comparison with salt, sugars are used at higher levels and contribute many more functions to the final product – hence sugars are functionally different to salt and cannot be treated in the same manner. There is also some evidence to suggest that the factors that underlie the liking for sugar and salt may differ; test subjects quickly reverted to previous sugar ‘liking’ levels even after several months of reduced sugar intake. This research suggests that those looking to replicate salt reduction strategies for sugar may be disappointed .
There are a range of sugar replacers that can be used in foods and drinks to reduce/replace sugars. Typically, they only replace one function of the sugars, sometimes two, but they cannot replace all sugars in all products. The types of ingredients that can be used as sugar replacers are summarised in Table 2.
The challenges of reformulation
In some products, the reformulation challenge is relatively easy and has already been achieved in many instances. In beverages, the sweetness of the sugars can be readily replaced with high potency sweeteners, which can be used in smaller quantities, while the bulk of the sugars is replaced by water, thus delivering a calorie reduction. In the UK, this type of reformulation has been underway for over 20 years. In 1994 the soft drinks regulations were revoked and beverages have been reformulated ever since. The UK has one of the widest choices of drinks ranging from regular sugar containing drinks to diet, sugar free options and everything in between.
Similarly, in chewing gums, it is now almost impossible to buy a sugar containing chewing gum – the sugars have been replaced by polyols, notably xylitol, which delivers excellent functionality in these products.
Other products, particularly those containing significant levels of starch and/or fat combined with sugars, are more challenging to reformulate.
The key issues encountered with reformulation are: increased numbers of ingredients, ingredients that consumers are not familiar with and would not be found in their kitchen cupboards, increased warnings on pack, insignificant changes to the energy content of products and a potential impact of food safety. These issues will be illustrated using the examples below.
||High potency sweeteners, polyols
||Gums, thickeners, polyols
||Bulking agents, dietary fibres, polyols, gels, gums
||Preservatives eg benzoates and sorbat
||Polyols, glycerol, humectants
Table 2. Ingredients that can replace some of the functions of sugars 
Increased and unfamiliar ingredients
Traditionally sugars have been used to preserve foods providing nutritious and safe foods outside the usual harvest season e.g. jams, preserves, chutneys. A sugar free preserve from the USA illustrates the number of additional ingredients that are required to deliver a similar product without the use of sugars. This approach does however deliver a reduction in calories – regular jam contains 243 kcal/100g, while sugar free preserve contains 58 kcal/100g. The ingredient declaration for the two products is presented in Figure 1.
In regular jam, sugar is performing many functions – it provides sweetness, bulk and high solids, which assist the setting of pectin. The citric acid provides a low pH, which results in inversion of the sucrose to give glucose and fructose and thus increases the number of molecules present, increasing the preservative action of the sugars. The reducing sugars glucose and fructose also react providing flavour and colour to the jam.
Replacing sugars in jams increases the number of ingredients: regular jam contains four ingredients, while sugar free preserve contains twelve. In the sugar free preserve, sucralose (a high potency sweetener) provides the sweetness, polydextrose and maltodextrin (bulking agents) and pectin (gelling agent) provide bulk and texture to the product. Most of the bulk is provided by high molecular weight compounds because regular High Methoxy pectin will not gel – the sugar free preserve relies on the action of calcium (chloride) to gel the Low Methoxy pectin present. Again, due to low numbers of molecules, the water activity (aw) is high and a preservative (potassium sorbate) is required to maintain shelf life. The addition of flavour and colour is required to maintain the appearance and taste of the product.
Figure 1 Regular jam vs sugar free preserve (US product)
Increased warnings on label
The use of many sugar replacers is controlled by the Additives Regulation EU Regulation 1129/2011. This regulation specifies which additives can be used in which products and also sets limits and conditions for use. Two labels that also must accompany the use of specific additives are ‘contains a source of phenylalanine’ for products containing aspartame and‘excessive consumption may cause laxation’ for products containing above 10% polyols. Both aspartame and polyols are additives that can be used to replace/reduce sugars in food products.
Negligible change in energy content
When consumers see a reduced sugars claim, they expect to see a resultant reduction in energy. Research at Leatherhead Food Research  has indicated that consumers see sugar as a proxy for calories and expect a reduction in calories if a reduced sugars claim is made on pack. This is illustrated in Figure 2, which shows an expectation of a similar reduction in calories for each reduction in sugar in a product.
When consumers see a reduced sugars claim, they expect to see a resultant reduction in energy.”
The Childhood Obesity plan  also highlights that sugar reductions should be accompanied by reductions in calories and should not be compensated for by increases in saturated fat. In practice this is very difficult to achieve in many products as illustrated by the following examples:
(i) Breakfast cereals
Breakfast cereals are composed principally of starch from a number of cereal grains – wheat, corn, oats etc. The sugars are added to provide structure, taste and colour. Starch and sugars are carbohydrates and both have 4 kcal/g. Consequently, when sugars are reduced in cereal products, there is a negligible change in the energy content of breakfast cereals (without the addition of fibre). This is illustrated in Table 3. The data has been collated from the nutritional panels of 3 breakfast cereals from the same company. Even though there is a significant reduction in sugars – 40% and 78% respectively, there is very little change in the energy provided per bowl (30g) of cereal: 113 and 114 kcal respectively. As the sugars are reduced, the starch becomes a higher percentage of the cereal and thus there is no change in calories.
(ii) Stepwise reduction in shortbread
The challenge is very similar with biscuit products – Table 4 (p41) illustrates a stepwise reduction in sugar in a shortbread recipe. Reducing sugar in the recipe might be expected to result in a significant calorie reduction, however as the sugar is reduced, the fat (butter) becomes a higher proportion of the product and as fat has 9 kcal/g, the calories actually increase. Therefore, a simple stepwise reduction of sugar in this product will not deliver the anticipated calorie reduction.
(iii) Calorie increase
The Food and Drink Federation and Leatherhead Food Research recently published a guide to assist small and medium sized companies with reformulation. They highlighted a product containing fat, starch and sugars which, when reformulated to give a 36% reduction in sugars, actually delivered an increase in calories. The change in composition required an increase in fat, starch and protein to balance the reduction in sugars (Table 5). It is also important to note that this product would not be allowed to use a reduced sugar claim as it has an increase in calories. EU Commission regulation EU No 1047/2012 states that the claim‘reduced sugars’, and any claim likely to have the same meaning for the consumer, may only be made if the amount of energy of the product bearing the claim is equal to or less than the amount of energy in a similar product.
(iv) Food safety
Water is ubiquitous in foods and the amount and availability determine the shelf life of many products. Sugars are highly soluble and thus influence the water activity in many systems. The ability to retain water and in some cases even attract water (hygroscopicity) can also influence the texture of many foods. Problems can occur if sugars are reduced or replaced in food products; a well-documented outbreak of botulism in 1989 was associated with the replacement of sugar with aspartame in hazelnut puree products. Sugar was providing preservative benefits and preventing microbial growth in the processing and storage; replacement with aspartame changed the aw and allowed the growth of Clostridium botulinum in the product. This resulted in one death and 27 people suffering from botulism poisoning .
Figure 2. Consumer expectations of calorie reduction based on sugars reductions 
|| /serving 30g
|Regular sugar coated product
|‘Reduced’ sugar coated product
|Uncoated regular product
Table 3. The challenge of reducing sugars in breakfast cereals (pack values December 2016)
|Weight of sugar in recipe g
Table 4. Stepwise reduction of sugar in a shortbread recipe
Shortbread recipe: Butter 110g; Flour 175g; Caster sugar 50g (Delia Smith Complete Cookery Course p624)
Flour 4 kcal/g; butter 9 kcal/g; sugar 4 kcal/g
*Calculated calorie reduction = weight of sugar removed from recipe x 4 kcal
||Product before reducing
(g per 100g)
|Product after reducing
sugars (g per 100g)
Table 5. Effect of reducing sugars without replacement of a lower calorie ingredient in a product example with 22%
sugars and 23% fat
(reproduced with kind permission from FDF and Leatherhead Food Research) 
Reformulation Guide Spotlight on sugars for small to medium sized companies Aug 2016 FDF/Leatherhead Food Research
Sugar reformulation in food products is seen by some as the universal panacea for the obesity crisis. However, sugar reduction/replacement is not as straightforward as salt reformulation and may result in unintended consequences. Reformulation and, in particular, stepwise reduction may result in increased calories. Replacement with other ingredients is likely to require an increased number of additives unfamiliar to the consumer. To produce healthier (lower calorie) food products, a holistic approach must be taken to redesign foods so that ingredients deliver the maximum impact at the optimal level. Care must also be taken to avoid the ‘halo’ effect, where healthier products are seen as better: ‘therefore I can eat two’!
Professor Julian M Cooper FRSC, CChem, FIFST, CSci
Julian is a carbohydrate chemist with over 35 years’experience in the food industry. He is a visiting professor at the University of Reading and chairs the scientific committee at IFST, where he is also a Board Trustee. In 2015 he retired from Associated British Foods (British Sugar) and is now an independent consultant to the food industry. Julian is the author of the IFST peer reviewed Sugars Information Statement.
1. HM Government – Childhood Obesity A Plan for Action https://www.gov.uk/government/uploads/system/uploads/attachment_data/file/546588/Childhood_obesity_2016__2__acc.pdf
2. Sugars Information Statement – IFST http://www.ifst.org/knowledge-centre/information-statements/sugars
3. SACN Report Carbohydrates & Health Scientific Advisory Committee on Nutrition 2015 https://www.gov.uk/government/publications/sacn-carbohydrates-and-health-report
4. Reduced dietary intake of simple sugars alters perceived sweet taste intensity but not perceived pleasantness. P. M Wise, L Nattress, L. J. Flammer and G. K. Beauchamp American Journal of Clinical Nutrition 2016, vol 103, no 1, 50 - 60
5. Product Reformulation – can sugar be replaced in foods? J. M. Cooper International Sugar Journal 2012, Vol 114, 1365
6. Consumer understanding of sugars claims on food and drink products. Nutrition Bulletin, 37, 121 – 130 (2012) N. J Patterson, M. J. Sadler and J. M. Cooper https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3437484/
7. FDF/Leatherhead Food Research Reformulation Guide Spotlight on sugars for small to medium sized companies Aug 2016
8. Botulism in the UK. Brett M Eurosurveillance, Vol 4 Issue 01 January 1989