The health and wellness boom has precipitated huge growth in the low-cal and no-cal soft drinks market, and with it great strides in the development of artificial sweeteners. Annette Farr reports on how consumers, in their eagerness to reduce their calorie intake, have embraced the likes of aspartame, sucralose and acesulfame-K.

As health and obesity issues continue to monopolise the soft drinks industry, the choice and use of sweeteners has become ever more important. High-intensity sweeteners with no calories are used in diet, low-cal, and no-cal drinks while bulking sweeteners, such as erythritol, provide sweetness, body and mouthfeel.

Past years have seen diet and low-calorie drinks experience unprecedented growth. Analyst Canadean reports that in the US almost 30% of the carbonates consumed are so-called 'diet' products, up from around a quarter in 2002. In Australasia, they account for 20% and in West Europe they represent 19% of the market.

Research conducted in the UK by Ajinimoto, the leading Japanese producer of the sweetener aspartame, shows that the number of shoppers seeking out sugar-free labelling is on the increase. When asked in 2002 what ingredients they look out for on a new soft drink pack, 8% of respondents said 'sugar-free'. By 2006, this figure had doubled to 16%. When parents were asked what they look for in new soft drinks for children, 27% said they scanned products for 'sugar-free' claims and 42% of parents said they wanted their children to consume less sugar.

Further, despite occasional media scares over artificial sweeteners, when questioned about sweeteners as a category, just ten people from a sample of 1,037 expressed any concern.

These figures might be good news for suppliers of sweetening systems but these are challenging times nonetheless.

Last month, Tate & Lyle issued a warning that Splenda - its sucralose-based product - was not performing as well as expected. After an initial burst of activity, which even saw Coca-Cola carry the Splenda brand logo on the packaging of a new diet variant, sales have stagnated, particularly in the US. This after Tate & Lyle had doubled the capacity of its plant in Alabama and commissioned a new factory in Singapore.

Aspartame, the intense sweetener made from two amino acids, aspartic acid and phenylaline (200 times sweeter than sugar), has been the subject of a number of safety scares linked to cancer, all of which have been subject to scrutiny.

The European Food Safety Authority reviewed the findings of the Ramazzini Institute's study which said aspartame, at certain doses, causes lymphomas and leukaemia cancers in female laboratory animals, and subsequently pronounced aspartame safe for use in soft drinks. In Australia, the Cancer Epidemiology Biomarkers and Prevention Group confirmed that aspartame is not carcinogenic. Tony Gentile, CEO of the Australian Beverages Council, said: "Aspartame has been one of the most studied food additives in the world and it continues to be safe for consumption."

Aspartame leads the intense sweeteners market with a 44% share followed by Splenda with 26%. Many manufacturers find that a blend of low-calorie sweeteners produces the best taste. In the UK, Diet Coke, sweetened with a blend of aspartame and acesulfame-K, outsells the sugar sweetened variant.

Where providing sweetness for regular drinks is concerned, High Fructose Corn Syrup (HFCS) continues to come under attack, particularly in the US, over obesity and labelling issues. HFCS is made from corn comprising glucose and fructose.

Defending the obesity charge, the American Beverage Association (ABA) cites a study published in Nutrition Today. Dr Richard Adamson, the ABA's senior scientific consultant, said: "This study demonstrates HFCS is similar to table sugar in terms of the body's physiological and hormonal responses and in terms of hunger and satiety. Based on these findings HFCS is unlikely to have a unique effect on obesity."

Labelling controversy has dogged the use of the words 'all-natural'. The Washington-based pressure group The Center for Science in the Public Interest (CSPI) maintains that while the glucose and fructose in HFCS are identical to naturally occurring glucose and fructose, the fact that chemical bonds are broken and rearranged in their production disqualifies them from being called natural.

Last year, the CSPI challenged Cadbury Schweppes to remove the '100% natural' claim on the rebranded 7-Up, and only last month took up the cause of a Florida woman suing Kraft Foods for falsely claiming that its Capri Sun brand is 'all natural' when it is sweetened with HFCS.

Despite these issues ingredient manufacturers continue to innovate. German company Wild is now offering two versions of its natural fruit sweetener Fruit Up: 'Classic' for still fruit juice drinks and 'Premium' for sports, near-water, herbal or tea drinks with all natural ingredients.

Cargill is seeking EU approval for Xtend Sucromalt, its latest slowly digestible sweetener. Xtend Isomaltulose, another of Cargill's slowly digestible sweeteners, already has Novel Foods approval in Europe. Both sweeteners have GRAS (Generally Recognised As Safe) status in the US. Together they offer the benefits of slow energy release, a blunted glycaemic response and a sweet taste.

Meanwhile, the German company Palatinit has developed Palatinose. Derived from sucrose, it has the same calorific value as sugar and a similar sweetness profile, but is tooth-friendly. It claims to be the only low and slow glycaemic carbohydrate to supply energy in the form of glucose over a longer period of time than sucrose. The company says it is already proving popular with manufacturers of sports, energy and wellness drinks in the US and Europe.