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Toribio L.,University of Valladolid | Bernal J.L.,University of Valladolid | Nozal M.J.,University of Valladolid | Arnaiz E.,University of Valladolid | Bernal J.,Institute of Industrial Fermentations
Food Analytical Methods | Year: 2011

The sequential supercritical fluid extraction of neutral and polar lipids from corn is presented in this work. The effect of the different parameters on the extraction was studied. It was found that pressure and temperature were the parameters that most affected the extraction of neutral lipids using pure CO 2. The best results were obtained at 300 bar and 60°C. Flow rate and dynamic extraction time had also some influence on the extraction yield. In this way, working at 3 ml/min for 150 min, the percentage of remaining lipids was lower than 1. 0%. Afterwards, and in order to extract the polar lipids, the residual corn material was subjected to the supercritical fluid extraction using CO 2 modified with methanol. The amount of lipids extracted increased when the percentage of methanol and the dynamic extraction time rose, achieving the best results when using 15% (v/v) methanol and 90 min of dynamic extraction. The developed method was successfully applied to obtain, by gas chromatography-mass spectrometry, the fatty acid profile of several genetically modified corn samples and their isogenic lines. © 2010 Springer Science+Business Media, LLC.

Arnaiz E.,University of Valladolid | Bernal J.,Institute of Industrial Fermentations | Martin M.T.,University of Valladolid | Garcia-Viguera C.,CSIC - Center of Edafology and Applied Biology of the Segura | And 2 more authors.
European Journal of Lipid Science and Technology | Year: 2011

The supercritical fluid extraction (SFE) and fractionation of lipids from broccoli leaves is presented in this work. For this purpose the effect of the different variables on the extraction was studied, obtaining the best results at 60°C, 300bar and 3mL/min. Two different fractions were obtained: First, the samples were extracted with pure CO 2, and afterward the residual material was extracted using CO 2 modified with 15% of methanol. The total fatty acid content of the extracts was determined by GC-MS and compared with those results obtained by Soxhlet extraction with hexane and a chloroform/methanol (2:1) mixture. The SFE extracts presented a higher percentage of unsaturated fatty acids, especially the polyunsaturated 18:3 n-3. The methodology was successfully applied to the analysis of the fatty acid composition of the leaves from five different cultivars of broccoli. In all the samples the main fatty acids were α-linolenic (18:3 n-3), linoleic (18:2 n-6), and palmitic (16:0). Among the different cultivars analyzed, Naxos variety presented the highest levels in fatty acids, while Parthenon and Viola the lowest. Practical applications: The proposed method allows the fractionation of lipids from broccoli leaves using a small volume of organic solvent and mild conditions. This is advantageous compared to conventional methods where large volumes or organic solvents are used, and the cost and time for the removal of these solvents, along with the possibility of degradation and toxicity, are the major disadvantages. The results obtained contribute to a better compositional characterization and a possible revaluation of this by-product as a source of biologically active compounds. © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Simo C.,Institute of Industrial Fermentations | Dominguez-Vega E.,University of Alcala | Marina M.L.,University of Alcala | Garcia M.C.,University of Alcala | And 2 more authors.
Electrophoresis | Year: 2010

A CE-TOF MS proteomic approach was applied for the analysis of hydrolyzates from complex soybean protein mixtures. After CE-TOF MS method development, the new approach provided the simultaneous analysis of more than 150 peptides from the soybean protein fraction soluble in ACN-water (80/20 v/v). The method is fast (about 30 min of analysis per sample) and is characterized by a relatively low running cost. The approach was used to study the substantial equivalence between a genetically modified variety of soybean compared with its traditional counterpart. No significant differences were found between the two studied soybeans based on the protein fraction studied. The capacity of the CE-TOF MS method to analyze complex mixtures of peptides in short times opens interesting possibilities in the growing Foodomics area. © 2010 WILEY-VCH Verlag GmbH & Co. KGaA.

Sazelova P.,Czech Institute of Organic Chemistry And Biochemistry | Kasicka V.,Czech Institute of Organic Chemistry And Biochemistry | Leon C.,Institute of Industrial Fermentations | Ibanez E.,Institute of Industrial Fermentations | Cifuentes A.,Institute of Industrial Fermentations
Food Chemistry | Year: 2012

Capillary zone electrophoresis (CZE) has been applied to separation and characterisation of enzymatic (tryptic) hydrolysates of water-soluble proteins from Bacillus thuringiensis (Bt)-transgenic (Aristis-Bt) and two native non-transgenic (Aristis and Coventry) maize varieties. Water-soluble proteins were extracted from the flour of these maize species and digested by bovine pancreatic trypsin immobilised on agarose gel in 100 mM ammonium hydrocarbonate buffer, pH 7.9. The yielded tryptic digests of proteins were analysed by CZE in four acidic background electrolytes (BGEs) (100 mM H 3PO 4, 50 mM Tris, pH 2.25; 500 mM acetic acid, pH 2.54; 200 mM formic acid, 200 mM acetic acid, pH 2.05; and 200 mM iminodiacetic acid, pH 2.26) using a lab-made CZE apparatus equipped with bare fused silica capillary and UV-absorption detector operating at 206 nm. Among the tested BGEs, the best resolution of the tryptic peptides of extracted proteins of the above three maize species was obtained in isoelectric BGE, 200 mM iminodiacetic acid, pH 2.26. Selected resolved tryptic peptides of proteins were characterised by effective electrophoretic mobilities and corrected (migration times normalised) peak areas. Some significant relative qualitative and quantitative differences in CZE-UV profiling of tryptic protein digests were found, which can be potentially used to differentiate transgenic Aristis Bt and non-transgenic Aristis varieties or two native non-transgenic varieties, Aristis and Coventry. © 2012 Elsevier Ltd. All rights reserved.

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