Brenda Lee Simas Porto

20 Years of Fatty Acid Analysis by Capillary Electrophoresis

A review taking into account the literature reports covering 20 years of fatty acid analysis by capillary electrophoresis is presented. This paper describes the evolution of fatty acid analysis using different CE modes such as capillary zone electrophoresis, non-aqueous capillary electrophoresis, micellar electrokinetic capillary chromatography and microemulsion electrokinetic chromatography employing different detection systems, such as ultraviolet-visible, capacitively coupled contactless conductivity, laser-induced fluorescence and mass spectrometry. In summary, the present review signals that CE seems to be an interesting analytical separation technique that is very useful for screening analysis or quantification of the usual fatty acids present in different matrices, offering short analysis times and a simple sample preparation step as inherent advantages in comparison with the classical methodology, making it a separation technique that is very attractive for quality control in industry and government agencies.

Analysis of amino acids, proteins, carbohydrates and lipids in food by capillary electromigration methods: a review

A review of the literature covering the evolution of amino acid, protein, lipid and carbohydrate analysis in food samples by electromigration techniques over the last 20 years is presented. The manuscript summarizes different modes, including capillary zone electrophoresis, micellar electrokinetic chromatography, capillary electrochromatography, capillary gel electrophoresis, capillary isotachophoresis, non-aqueous (or nonaqueous) capillary electrophoresis, capillary isoelectric focusing and microfluidic chip electrophoresis, employing different detection systems, such as ultraviolet-visible absorption, laser-induced fluorescence, mass spectrometry, amperometric detection, and capacitively coupled contactless conductivity detection. Briefly, the present review evidences that CE is a very interesting analytical separation technique for food analysis, offering short analysis times and versatility in a simple sample preparation step as inherent advantages compared to classical chromatographic methodologies, which make it a separation technique that is very attractive for quality control in industry and government agencies.

Capillary zone electrophoresis for fatty acids with chemometrics for the determination of milk adulteration by whey addition.

Adulteration of milk with whey is difficult to detect because these two have similar physical and chemical characteristics. The traditional methodologies to monitor this fraud are based on the analysis of caseinomacropeptide. The present study proposes a new approach to detect and quantify this fraud using the fatty acid profiles of milk and whey. Fatty acids C14:0, C16:0, C18:0, C18:1, C18:2 and C18:3 were selected by gas chromatography associated with discriminant analysis to differentiate milk and whey, as they are present in quite different amounts. These six fatty acids were quantified within a short time by capillary zone electrophoresis in a set of adulterated milk samples. The correlation coefficient between the true values of whey addition and the experimental values obtained by this technique was 0.973. The technique is thus useful for the evaluation of milk adulteration with whey, contributing to the quality control of milk in the dairy industry.

Comparative Study of the Lipid Profiles of Oils from Kernels of Peanut, Babassu, Coconut, Castor and Grape by GC-FID and Raman Spectroscopy

The characterization of the lipid profiles of oils extracted from the kernel of seeds and nuts of peanut (Arachis hypogaea), babassu (Attalea speciosa), coconut (Cocos nucifera), castor (Ricinus communis) and grape (Vitis vinifera) was performed by using Raman spectroscopy and gas chromatography with flame ionization detector (GC-FID). Chromatographic analyses showed that coconut and babassu oils are composed essentially by saturated fatty acids (SFA), whereas the others are composed mainly by unsaturated fatty acids (UFA). The comparison of commercial and homemade castor oils showed the former have a lower level of ricinoleic acid at ca. 58%. Spectroscopic analyses of three distinct castor oils showed their profiles could be differentiated by marker features ascribed to carbonyl modes which were correlated with storage time. The comparison between the Raman spectra of standard samples of fatty acids with the samples of oils allowed the assignment of the spectroscopic features and the characterization of marker bands for the degree of unsaturation.