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:B Raposa, R Pónusz, G Gerencsér, F Budán, Z Gyöngyi, A Tibold, D Hegyi, I Kiss, Á Koller, and T Varjas
Since the middle of the 20th century, the use of foodadditives became widespread and increasing in each food groups. Both producers and consumers have higher expectations for various food products, which also
Summary Many years ago, thermal analysis earned its place as a current instrumentation technique in assisting/solving the analytical problems of pharmaceuticals. A relative new trend is the study of the thermal stability of food additives in connection with the molecular structure. The studied compounds were: natrium and potassium glutamate, respectively natrium, potassium and calcium benzoate. The thermogravimetric data (TG) were obtained in dynamic nitrogen atmosphere, with open Pt crucible and heating rates of 5, 7, 10 and 12 K min-1, using a Perkin-Elmer TGA7 equipment. In order to estimate the non-isothermal kinetic parameters, the Friedman's differential-isoconversional method and the method suggested by Budrugeac and Segal (based on the compensation effect) were used. A variation of the activation energy vs. conversion was observed by using Friedman's method. The discrimination between the different reaction steps was performed by the non-parametric kinetic method, suggested by Sempere, Nomen and Serra. This is due to a complex process. The thermal stability data are very important for avoiding a possible misuse by processing of the studied food additives.
Authors:J. Slezsák, É. Szabó, S. Gergely, and A. Salgó
Near-infrared (NIR) spectrophotometers with different optical arrangements were used to measure the diffusely reflected electromagnetic radiation of different types of food additives in polyethylene (PE) foils. Eight compounds, frequently used in food process – but also in other industries –, were measured by different NIR spectrophotometers. The detected (‘as is’) and mathematically transformed (by scatter correction, second derivative combined with smoothing) NIR spectra were processed with multivariate data analysis (MDA). In this matter, unsupervised methods like principal component analysis (PCA) and cluster analysis (CA) were used, which techniques do not require prior information and reference measurements. The aim of the present study was to distinguish food additives by the help of the applied chemometric methods based on NIR spectra detected via the PE foils. Results indicated that distinction of different food additives and compounds with NIR methods is possible not only with the conventional sample preparations and handlings, but also without breaking the packaging.
Authors:Huan Zhang, Pan Wang, Ai-Jun Zhang, Xuan Li, Ji-Hong Zhang, Qi-Lian Qin, and Yi-Jun Wu
The housefly is an important resource insect and the housefly larvae are ideal source of food additives. The housefly larvae protein hydrolysates were obtained by enzymatic hydrolysis by alcalase and neutral proteinase. Their antioxidant activities were investigated, including the superoxide and hydroxyl radicalscavenging activity, 1,1-diphenyl-2-picrylhydrazyl (DPPH) scavenging activity, reducing power and metal chelating activity. The antioxidant activities of both hydrolysates increased with their increasing concentrations. The alcalase hydrolysate (AH) showed higher scavenging activities against hydroxyl radical and superoxide anion radical at low concentrations and higher metal-chelating activity than the neutral proteinase hydrolysate (NPH). The NPH exhibited higher scavenging activity against DPPH free radical and higher reducing power than the AH. Both hydrolysates showed more than 50% superoxide anion radical-scavenging activity at 10 μg/mL. These results indicate that both housefly larvae protein hydrolysates display high antioxidant activities and they could serve as potential natural antioxidant food additives.