Sweeteners for Soft Drinks

An important characteristic of soft drinks is their sweet taste, which is derived from natural sweetening concentrates as described above. However, other raw materials are also used. Table 5.14 provides an overview of the various sweeteners. 

Sugar Other sugars Sugar substitutes High-intensity sweeteners  

Sucrose Glucose Inverted sugar Corn syrup High-fructose corn syrup (isoglucose) Honey Fructose Maltitol Sorbitol Isomalt Xylitol Mannitol Trehalose Tagatose Isomaltulose Acesulfame-K Aspartame Cyclamate Saccharine Sucralose Neohesperidin DC Thaumatine Stevia extract Lo-Han extract 

The various types of sugar have traditionally been the most common sweeteners employed in soft drinks. Sucrose, invert sugar syrup, high-fmctose com symp and com symp perform three functions in beverages  

The sensory appearance of sucrose is used as the reference value for the desired sweetness impression. Comparable sweetening can be achieved with invert sugar symp or high-fmctose com symps. 

---

Frazierm, R.A. et ah. Development of a capillary electrophoresis method for the simultaneous analysis of colours, preservatives and sweeteners in soft drinks, J. 

Fort he determination of preservatives and sweeteners in soft drinks or fruit juices LC analysis with UV detection is widely used. The sample pretreatment, prior to LC analysis, often consists only of degassing, filtration and dilution of the Uqirid [2]. Sometimes a Uqirid-Uqitid extraction, suitable not only for soft drinks but also for more complex matrices, is appUed [3]. Chemometric methods appUed to overlapped spectra offer the advantage of minimizing or eliminating sample preparation by allowing to simirltaneoirsly determining one or more analytes in relatively complex matrices. 

The main intense sweeteners currently permitted for use in the major markets of Europe and the United States are not natural and have had to go through a food additive approval procedure. Within the European Union, approval is controlled by the EU Commission, with the aim of achieving harmonisation across member states. The current system allows for temporary national approval (and this was the mechanism by which sucralose was approved in the United Kingdom). This in turn allows the other EU countries time to review the data and either approve or reject each product within a specified period. Within the European Union, approved sweeteners are assigned an E number and can also be assigned a maximum use level within a specific application (e.g. soft drinks). The maximum use levels for sweeteners in soft drinks in the European Union are given in Table 4.2. 

Since the publication of the first edition of this book, a few more validated methods for the analysis of soft drinks ingredients have been documented. When the first edition was published in 1998, only a handful of methods for the analysis of soft drinks ingredients had been collaboratively tested in the Association of Official Analytical Chemists (AOAC) official methods manual, and only two of these were modern HPLC approaches. At that time, no methods could be found in the British Standards catalogue. Inspection of the British Standards website (http //www.bsi-global.com) now shows that there are two standardised approaches for the analysis of high-intensity sweeteners in soft drinks, both of which use HPLC. This overall lack of standardisation of methods is probably because a soft drink s matrix is relatively straightforward, without many of the problems associated with other areas of food analysis, and so the industry has not felt the need to standardise the test methods. 

Benzoic and sorbic acids are now normally assayed using HPLC. As discussed in the section on the analysis of sweeteners, some of the HPLC methods developed for soft drinks actually allow the separation of both sweeteners and preservatives in one ran, for example, Williams (1986), Hagenauer-Hener et al., (1990) and the EU method for sweeteners (Anon, 1999a), although the preservatives were not included in the collaborative trial of the method. The separation of benzoic and sorbic acids can sometimes be difficult and care should be taken that the system will actually resolve these two preservatives if they are present otherwise spurious results can be obtained. The pH of the solvent is a critical feature that allows the separ ation of these two preservatives. 

Some countries have local legislative directives in place, but there is no harmonised European law for soft drinks. Nevertheless, some horizontal legislation needs to be considered (Table 5.12). Additives, like colours, sweeteners and others, are established within the European Union. 

The main utihty of saccharin had been in beverages and as a table-top sweetener. Upon the approval of aspartame for carbonated beverages in 1983, aspartame displaced saccharin in most caimed and bottied soft drinks. However, saccharin is stiU used, usually blended with aspartame, in carbonated soft drinks dispensed from soda fountains. 

To meet consumer demands, manufacturers are developing new nonnutritive sweeteners that more closely match the taste and mouthfeel of sucrose. There are several nonnutritive sweeteners currentiy pending FDA approval for use in soft drinks. They include sucralose [56038-13-2] aUtame [80863-62-3] encapsulated aspartame, cyclamates, and acesulfame-K [55589-62-3] also known as paUtinit. 

New packaging and packaging materials seem imminent. New nonnutritive sweeteners promise increased shelf life and improved taste for a calorie conscious society. Easter, more efficient production methods and equipment are being developed every day. Soft drink manufacturers wkl continue to expand markets overseas and attempt to increase per capital consumption in existing markets. 

When you crack open a can of Coca Cola or Pepsi, you are tasting some of the fruits of bioohemioal engineering Most nondiet soft drinks sold in the United States are sweetened with high-fruotose oorn syrup (MFCS), a substitute for the natural sugar that oomes from cane and beets. MFCS, produced by an enzymatic reaction, is an example of the suooessful application of chemical engineering principles to bioohemioal synthesis. So successful, in fact, that more than 1.5 billion of MFCS was sold in the United States last year. 

Numerous CE separations have been published for synthetic colours, sweeteners and preservatives (Frazier et al., 2000a Sadecka and Polonsky, 2000 Frazier et al., 2000b). A rapid CZE separation with diode array detection for six common synthetic food dyes in beverages, jellies and symps was described by Perez-Urquiza and Beltran (2000). Kuo et al. (1998) separated eight colours within 10 minutes using a pH 9.5 borax-NaOH buffer containing 5 mM /3-cyclodextrin. This latter method was suitable for separation of synthetic food colours in ice-cream bars and fmit soda drinks with very limited sample preparation. However the procedure was not validated for quantitative analysis. A review of natural colours and pigments analysis was made by Watanabe and Terabe (2000). Da Costa et al. (2000) reviewed the analysis of anthocyanin colours by CE and HPLC but concluded that the latter technique is more robust and applicable to complex sample types. Caramel type IV in soft drinks was identified and quantified by CE (Royle et al., 1998). 

There is a recent trend towards simultaneous CE separations of several classes of food additives. This has so far been applied to soft drinks and preserved fruits, but could also be used for other food products. An MEKC method was published (Lin et al., 2000) for simultaneous separation of intense sweeteners (dulcin, aspartame, saccharin and acesulfame K) and some preservatives (sorbic and benzoic acids, sodium dehydroacetate, methyl-, ethyl-, propyl- and isopropyl- p-hydroxybenzoates) in preserved fruits. Ion pair extraction and SPE cleanup were used prior to CE analysis. The average recovery of these various additives was 90% with good within-laboratory reproducibility of results. Another procedure was described by Frazier et al. (2000b) for separation of intense sweeteners, preservatives and colours as well as caffeine and caramel in soft drinks. Using the MEKC mode, separation was obtained in 15 min. The aqueous phase was 20 mM carbonate buffer at pH 9.5 and the micellar phase was 62 mM sodium dodecyl sulphate. A diode array detector was used for quantification in the range 190-600 nm, and limits of quantification of 0.01 mg/1 per analyte were reported. The authors observed that their procedure requires further validation for quantitative analysis. 

Approved in 1981 as a table top sweetener and for dry foods, aspartame was permitted in carbonated soft drinks in 1983, and in 1996 its approval was extended to all foods and beverages. There has been controversy over the role a Public Board of Inquiry played in the approval process, but this has been discounted in reports by the American Medical Association (Council of Scientific Affairs, 1985) and Stegink (1987). Reports of adverse reactions began almost immediately after approval in the 1980s, and by mid-1984 more than 600 complaints had been received by the FDA. Reports of adverse reactions peaked in 1985, when over 1,500 complaints were received by ARMS, and have been declining since then. As of June 2000, ARMS had received a total of 7,335 complaints about aspartame, with 47% of complaints linked to diet soft drinks, followed by 27% of complaints attributed to table top sweeteners. All other product categories were mentioned in fewer than 10% of complaints. 

An electrophoretic method was developed for the simultaneous determination of artificial sweeteners, preservatives and colours in soft drinks. The samples were degassed by sonication, filtered and used for analysis without any other pretreatment. Measurements were realized in uncoated fused-silica capillaries, the internal diameter being 50 ptm. Capillary lengths were 48.5 cm (40 cm to the detector) and 65.4 cm (56 cm to the detector). Capillaries were conditioned by washing them with (1 M sodium hydroxide (10 min), followed by 0.1 M sodium hydroxide (5 min) and water (5 min). Samples were injected hydrodinamically (250 mbar) at the anodic end. Analyses were performed at a voltage of 20 kV and the capillary temperature was 25°C. Analytes having ionizable substructure... 

R.A. Frazier, E.L. Inns, N. Dossi, J.M. Ames and H.E. Nursten, Development of a capillary electrophoresis method for the simultaneous analysis of artifical sweeteners, preservatives and colours in soft drinks. J. Chromatogr.A, 876 (2000) 213-220. 

---