Natural sweeteners: analysis

RPLC with MS detection was used for the analysis of seven artificial sweeteners (aspartame, saccharin, acesulfame-K, neotame, sucralose, cyclamate, and alitame) and one natural sweetener (stevioside). Samples were extracted using methanokwater and injected without any cleanup into the LC—MS system. Separation is carried out using a Cis column and gradient elution. Sweeteners were quantified using selective-ionization recording (SIR) at m/z 178, 397, 377, 293, 641, 312, 162, and 182 for cyclamate, sucralose, neotame, aspartame, stevioside, alitame, acesulfame-K, and saccharin, respectively, with a warfarin sodium m/z = 307) used as an internal standard [24]. For a detailed discussion of other analytical methods to determine artificial sweeteners, refer to [25]. 

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). 

The molecules produced by living organisms, natural products, are employed in our lives as flavors, fragrances, pharmaceuticals, nontraditional medicines, dyes, and pesticides, among other uses. The products of chemistry are employed in our food as preservatives, artificial sweeteners, thickeners, dyes, taste enhancers, flavors, and textnring agents. Chemistry creates such key materials as plastics, ceramics, fabrics, alloys, semiconductors, liquid crystals, optical media, and biomaterials. Chemistry also does many kinds of analysis and these include measurements of air quahty, water quality, food safety, and the search for substances that compromise the enviromnent or workplace safety. 

Although sugars are found in juices, the high-intensity sweeteners are not. However, they are often used in juice-based drinks or nectars, and here it is important to ensure that there is resolution of the sweeteners of interest from the compounds naturally present in fruit juices. This can be a particular problem in drinks with a high juice content as naturally occurring polyphenolic materials in the juice can disturb the analysis. 

Stable isotope ratio analysis Adulteration of fruit juices or honey by addition of bulk sweeteners can be detected by stable isotope ratio mass spectrometric analyses, because the naturally occurring carbon isotope ratio of to in honey and fruit is different from that in corn or sugarcane although not from that in sugar beet. The oxygen isotope ratio may be used for beet sugar addition. 

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