Analysis of Artificial Sweeteners

Bidlingmeyer, B. A. Schmitz, S. The Analysis of Artificial Sweeteners and Additives in Beverages by HPLG, /. Chem. Educ. 1991, 68, A195-A200. 

FRAZIER R A, INNS E L, DOSSI N, AMES J M and NURSTEN H E (2000b), Development of a capillary electrophoresis method for the simultaneous analysis of artificial sweeteners, preservatives and colours in soft drinks ,... 

The use of near-infrared spectroscopy is also an effective approach to the analysis of artificial sweeteners. The near-infrared spectrum of saccharin is shown in Figure 6.8c. As aromatic compounds are not very common in food products, the modes due to these compounds are therefore very useful. Although saccharin is found at low concentrations in foods, it is normally added as a concentrated solution and this can be monitored by near-infrared measurements in the presence of other ingredients. 

This technique has been established for many years particularly for water, soil and feeding-stuff analysis, where a large number of analyses are required for quality control or monitoring purposes. A number of applications have been published for food additives including aspartame (Fatibello et al., 1999), citric acid (Prodromidis et al., 1997), chloride, nitrite and nitrate (Ferreira et al., 1996), cyclamates (Cabero et al., 1999), sulphites (Huang et al., 1999 AOAC Int, 2000), and carbonate, sulphite and acetate (Shi et al., 1996). Yebra-Biumm (2000) reviewed the determination of artificial sweeteners (saccharin, aspartame and cyclamate) by flow injection. 

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... 

Computational chemistry methodology is finding increasing application to the design of new flavoring agents. This chapter surveys several useful techniques linear free energy relationships, quantitative structure-activity relationships, conformational analysis, electronic structure calculations, and statistical methods. Applications to the study of artificial sweeteners are described. 

Figure 32 shows a control cationic analysis of a selected batch of artificial sweetener Aspartam (L-aspartylphenylalanine methyl ester hydrochloride). In one analysis both the main component and the admixtures from the technological... 

F. 32. Cationic analysis of a selected hatch of artificial sweetener aspartam. 101<1 of the sample solution (97 mg/5 ml HjO) were analyzed, and the main component, the methyl ester of aspartyl-phenylalanine (MEAP) as well as the admixtures, sodium, methyl ester of phenylanine (MEP), and dimethyl ester of aspartyl-phenylalanine (di-MEAP) were separated. Leading and terminating cations NH and H , resp. The counterion was acetate... 

Fig. 33. Analysis of anions of a selected batch of artificial sweetener aspartam. 10 /il the sample solution (14 mg/S ml H2O) were analyzed and impui > ties 2,5-dioxopiperazine (DOP) and aspart -idienyl-alanine (AP) separated. Chloride and morpholino-ethanesulfonic acid served as the leading (L) and terminating (T) anions, resp.

FIGURE 24.4 FIA manifold used for the analysis of mixtures of artificial sweeteners using filter-supported BLMs. BLM bilayer lipid membrane CER carrier electrolyte reservoir E electrometer G ground P pump PS power supply R recorder RE reference electrode S syringe SI sample injector SWP Saran-Wrap partition UM ultrafiltration membrane W waste. 

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. 

M.9 In a combustion analysis of a 0.152-g sample of the artificial sweetener aspartame, it was found that 0.318 g of carbon dioxide, 0.084 g of water, and 0.0145 g of nitrogen were produced. What is the empirical formula of aspartame The molar mass of aspartame is 294 g-mol. What is its molecular formula ... 

The analysis of sweetmeats is usually limited to a determination of the sugar, which is the principal constituent. Sometimes, however, it is necessary to test for and determine the starch and extraneous mineral matters and to test for colouring substances and artificial sweetening agents, the methods already indicated for other sugar products being employed. 

Thin layer chromatography has been used in qualitative and quantitative analysis of saccharin, when present in artificial sweetening agents, beverages, food and pharmaceuticals. Several systems have been used and are listed in table 5-... 

The example of an LC chiral separation shown in Figure 12.6 serves to emphasise (a) that the demand for effective chiral selectors is such that even complex synthetic chiral selectors have been commercialised, and (b) the interest in chirality extends beyond pharmaceutical applications, being widespread and in this instance being found in food analysis. Aspartame (N-DL-cx-aspartyl-DL-phenylalanine methyl ester (Figure 12.7)) can exist as four stereoisomers, DD-, LL-, DL- and LD-. On an achiral column DD- and LL- would appear as a single peak which would be separable from another single peak arising from DL- and LD-. A chiral column is needed to separate the enantiomeric pairs (i.e. DD- from LL- and DL-from LD-). The LL-isomer is used as artificial sweetener (under the brand... 

Ion chromatography has also been described for the analysis of benzoic acid and sorbic acid, together with artificial sweeteners, caffeine, theobromine, and theophylline. The preservatives were analyzed on an anion-exchange analytical column operated at 40°C. 

Tri- and tetrasaccharides such as raffinose and stachyose may be separated under the chromatographic conditions given in Figure 3.208. As with phosphorylated monosaccharides, shorter analysis times are obtained when adding sodium acetate to the eluent. The same holds for the analysis of tri-and tetrasaccharides of the kestose group, which also function as artificial sweeteners. 

Raman spectroscopy can be used to examine samples contained inside polymeric packages. The pharmaceutical industry takes advantage of this Raman internal-package analysis in order to examine pills that are mixtures in which the active component is distributed in an excipient. Analysis of samples directly in gel capsules is possible. For forensic purposes, drugs can be examined without opening the evidence bags. Samples such as sugars and artificial sweeteners can be identified in paper packets. 

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]. 

Nikolelis, D. P. and S. Pantoulias, 2001. Selective continuous monitoring and analysis of mixtures of acesulfame-K, cyclamate, and saccharin in artificial sweetener tablets, diet soft drinks, yogurts, and wines using filter-supported bilayer lipid membranes. Anal. Chem. 73 5945-5952. 

The most important details of the published flow analysis procedures for acesulfame-K, cyclamate, and saccharin determination are shown in chronological order for each artificial sweetener in Table 24.1. 

No methods could be found in the literature for the individual flow analysis determination of acesulfame-K. The first flow analysis method for acesulfame-K was proposed by Nikolelis et al. 2001 [72]. This method allowed the electrochemical flow injection monitoring and analysis of mixtures of acesulfame-K, cyclamate, and saccharin using stabilized systems of filter-supported bilayer lipid membranes (BLMs). Detection consisted of t time-dependent appearance of a transient ion current peak in which the time-dependence could be used to distinguish the presence of different artificial sweeteners, and the peak magnitude was related to the concentration of the artificial sweetener. The BLM-based system is able to monitor each artificial sweetener in mixtures. The apparatus for the formation of stabilized BLMs is shown in Figure 24.4. The method also offers response times of less than 1 min, which are the fastest times reported for any similar... 

Only two flow analysis methods have been published for multianalyte determination including cyclamate as analyte. Both methods determine cyclamate with other artificial sweeteners. One of them used stabilized systems of filter-supported BLMs in a FIA manifold [72], and the other is based on CE with contactless conductivity detection employing a sequential injection manifold based on a syringe pump [77]. 

The determination of acesulfame-K, cyclamate, and saccharin individually or simultaneously with other artificial sweeteners and/or other food additives in foods, soft drinks, and tabletop sweeteners is very important for legal, health, and consumer safety aspects. Thus, reliable, simple, fast, sensitive, accurate, and robust analytical methods using low-cost equipment are essential to protect human health, meet the requirement to ensure product quality, and support the compliance and enforcement of laws and regulations pertaining to food safety. Flow analysis is shown to be a powerful analytical tool for the automated determination of acesulfame-K, cyclamate, and saccharin in food samples, and it is an interesting alternative for use in sweetener determinations when only one analyte is determined in a large number of samples. In the last few years, flow analysis... 

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