Authors:Irena Baranowska, Mirosława Zydroń, and Krzysztof Szczepanik
TLC methods have been developed for analysis of food pigments, sweeteners, and a preservative. Patent blue V, quinoline yellow, brilliant blue FCF, tartrazine, azorubine, ponceau 4R, curcumine, indigo carmine, cochineal, methyl violet, mixed carotenes, plain caramel, erythrosine B, and orange yellow S were separated on silica gel G with isopropanol-(12.5%) aqueous ammonia, 10 + 2 (
), as mobile phase. Aspartame, acesulfame K, sodium cyclamine, and benzoic acid were separated on thin layers of silica gel G with ethanol-isopropanol-(12.5%) aqueous ammonia, 10 + 40 + 1 (
), as mobile phase. These chromatographic systems were applied to the analysis of food additives in 23 sparkling and non-sparkling drinks.
Authors:Lucinéia de Carvalho, Milena Segato, Ronaldo Nunes, Csaba Novak, and Éder Cavalheiro
The thermal decomposition behavior of acesulfame-K (ACK), aspartame (ASP), sodium cyclamate (SCL), saccharine (SAC), and sodium
saccharine (SSA) were investigated. After re-crystallization of the commercial samples the compounds were characterized by
using elemental analysis, IR spectroscopy and thermoanalytical techniques (TG/DTG, DTA, and DSC). Evidences of hydrate water
loss were observed for SSA and ASP. Melting was detected for SSA and SAC. Each compound decomposed in a characteristics way.
The decomposition of APS and SAC took place completely, while ACK, SCL and SSA resulted in K2SO4, Na2SO4, and Na2SO4, as residues respectively. The Flynn-Wall-Ozawa method for kinetic calculations was applied for the volatilization of saccharine
resulting in Ea = 80 ± 1 kJ mol−1 and log A = 7.36 ± 0.07 min−1.
Authors:Levente Karaffa, Erzsébet Sándor, Erzsébet Fekete, and et al.
Fungi, in particular Aspergilli, are well known for their potential to overproduce a variety of organic acids. These microorganisms have an intrinsic ability to accumulate these substances and it is generally believed that this provides the fungi with an ecological advantage, since they grow rather well at pH 3 to 5, while some species even tolerate pH values as low as 1. 5. Organic acid production can be stimulated and in a number of cases conditions have been found that result in almost quantitative conversion of carbon substrate into acid. This is exploited in large-scale production of a number of organic acids like citric-, gluconic- and itaconic acid. Both in production volume as well as in knowledge available, citrate is by far the major organic acid. Citric acid (2-hydroxy-propane-1, 2, 3-tricarboxylic acid) is a true bulk product with an estimated global production of over 900 thousand tons in the year 2000. Till the beginning of the 20th century, it was exclusively extracted from lemons. Since the global market was dominated by an Italian cartel, other means of production were sought. Chemical synthesis was possible, but not suitable due to expensive raw materials and a complicated process with low yield. The discovery of citrate accumulation by Aspergillus niger led to a rapid development of a fermentation process, which only a decade later accounted for a large part of the global production. The application of citric acid is based on three of its properties: (1) acidity and buffer capacity, (2) taste and flavour, and (3) chelation of metal ions. Because of its three acid groups with pKa values of 3. 1, 4. 7 and 6. 4, citrate is able to produce a very low pH in solution, but is also useful as a buffer over a broad range of pH values (2 to 7). Citric acid has a pleasant acid taste which leaves little aftertaste. It sometimes enhances flavour, but is also able to mask sweetness, such as the aspartame taste in diet beverages. Chelation of metal ions is a very important property that has led to applications such as antioxidant and preservative. Moreover, it is a “natural” substance and fully biodegradable.