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Sanchez-Hernandez L.,University of Alcala | Castro-Puyana M.,Institute of Food Science Research CIAL | Marina M.L.,University of Alcala | Crego A.L.,University of Alcala
Electrophoresis | Year: 2012

The latest strategies and instrumental improvements for enhancing the detection sensitivity in chiral analysis by CE are reviewed in this work. Following the previous reviews by García-Ruiz et al. (Electrophoresis 2006, 27, 195-212) and Sánchez-Hernández et al. (Electrophoresis 2008, 29, 237-251; Electrophoresis 2010, 31, 28-43), this review includes those papers that were published during the period from June 2009 to May 2011. These works describe the use of offline and online sample treatment techniques, online sample preconcentration techniques based on electrophoretic principles, and alternative detection systems to UV-Vis to increase the detection sensitivity. The application of the above-mentioned strategies, either alone or combined, to improve the sensitivity in the enantiomeric analysis of a broad range of samples, such as pharmaceutical, biological, food and environmental samples, enables to decrease the limits of detection up to 10 -12M. The use of microchips to achieve sensitive chiral separations is also discussed. © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim. Source

Martos G.,Mount Sinai School of Medicine | Martos G.,Institute of Food Science Research CIAL | Lopez-Exposito I.,Mount Sinai School of Medicine | Lopez-Exposito I.,Institute of Food Science Research CIAL | And 3 more authors.
Journal of Allergy and Clinical Immunology | Year: 2011

Background: Egg white proteins are usually subjected to heating, making them edible for the majority of children with egg allergy. Objective: We sought to investigate the underlying mechanisms responsible for the reduced allergenicity displayed by heat-treated egg white allergens. Methods: C3H/HeJ mice were orally sensitized with ovalbumin (OVA) or ovomucoid and challenged with native or heated proteins to evaluate their allergenicity. Immunoreactivity was assessed by immunoblotting using sera from children with egg allergy. In vitro gastrointestinal digestion of native and heated OVA and ovomucoid was studied by SDS-PAGE and liquid chromatography. Intestinal uptake of intact native and heated OVA and ovomucoid by human intestinal epithelial (Caco-2) cells was investigated. Rat basophil leukemia cells passively sensitized with mouse serum and human basophils passively sensitized with serum from children with egg allergy were used to assess the effector cell activation by heated, digested, and transported OVA and ovomucoid. Results: Heated OVA and ovomucoid did not induce symptoms of anaphylaxis in sensitized mice when administered orally. Heating did not completely destroy IgE-binding capacity of OVA or ovomucoid but enhanced in vitro digestibility of OVA. Digestion of both OVA and ovomucoid diminished mediator release in rat basophil leukemia assay and basophil activation. Heating of allergens prevented transport across human intestinal epithelial cells in a form capable of triggering basophil activation or T-cell activation. Conclusion: Heat treatment reduces allergenicity of OVA and ovomucoid. This is partially a result of the enhanced gastrointestinal digestibility of heated OVA and the inability of heated OVA or ovomucoid to be absorbed in a form capable of triggering basophils. © 2010 American Academy of Allergy, Asthma & Immunology. Source

Herrera-Herrera A.V.,University of La Laguna | Hernandez-Borges J.,University of La Laguna | Rodriguez-Delgado M.A.,University of La Laguna | Herrero M.,Institute of Food Science Research CIAL | Cifuentes A.,Institute of Food Science Research CIAL
Journal of Chromatography A | Year: 2011

The present work describes a method based on solid-phase extraction (SPE) and ultra-performance liquid chromatography tandem mass spectrometry (UPLC-MS/MS) for the simultaneous determination of three quinolones (pipemidic acid, oxolinic acid and flumequine) and twelve fluoroquinolones (marbofloxacin, fleroxacin, pefloxacin, levofloxacin, norfloxacin, ciprofloxacin, enrofloxacin, danofloxacin, lomefloxacin, difloxacin, sarafloxacin, and moxifloxacin) in different infant and young children powdered milks. After suitable deproteination of the reconstituted powdered samples, a SPE procedure was developed providing recovery values higher than 84% (RSDs lower than 13%) for all the analytes, with limits of detection between 0.04 and 0.52 μg/kg. UPLC-MS/MS analyses were carried out in less than 10. min. Sixteen infant and young children powdered milk samples of different origin, type and composition bought at Spanish markets were analyzed. Residues of the selected antibiotics were not detected in any of the analyzed samples. © 2011 Elsevier B.V. Source

Simo C.,Institute of Food Science Research CIAL | Ibanez C.,Institute of Food Science Research CIAL | Gomez-Martinez A.,University Miguel Hernandez | Ferragut J.A.,University Miguel Hernandez | Cifuentes A.,Institute of Food Science Research CIAL
Electrophoresis | Year: 2011

In this work, four different metabolite purification approaches are investigated prior to metabolomics of human HT29 colon cancer cells. Namely, methanol deproteinization, ultrafiltration and two SPE methods using C18 and polymer-based cartridges were studied. The extracts were characterized via a metabolomic approach based on the application of CE TOF MS (CE-MS). CE-MS analysis time was less than 20min per sample and allowed the simultaneous and reproducible analysis of more than 80 metabolites in a single run with a minimum consumption of sample and reagents. Metabolome analysis revealed in some cases important differences among the studied metabolite purification procedures. No significant differences were observed in the metabolite profile using C18 and polymer-based cartridges, or between ultrafiltration and methanol deproteinization. However, important differences were observed in the metabolomic profiles obtained from SPE and methanol deproteinization samples. These results demonstrate the crucial role of the metabolite purification strategy in metabolomics since it can bias (and in some cases mislead) the conclusions achieved by the metabolomic study. © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim. Source

Valdes A.,Institute of Food Science Research CIAL | Garcia-Canas V.,Institute of Food Science Research CIAL | Simo C.,Institute of Food Science Research CIAL | Ibanez C.,Institute of Food Science Research CIAL | And 3 more authors.
Analytical Chemistry | Year: 2014

In this work, the contribution of carnosic acid (CA) and carnosol (CS), two major compounds present in rosemary, against colon cancer HT-29 cells proliferation is investigated using a comprehensive Foodomics approach. The Foodomics study reveals that CA induces transcriptional activation of genes that encode detoxifying enzymes and altered the expression of genes linked to transport and biosynthesis of terpenoids in the colon cancer cell line. Functional analysis highlighted the activation of the ROS metabolism and alteration of several genes involved in pathways describing oxidative degradation of relevant endogenous metabolites, providing new evidence about the transcriptional change induced by CA in HT-29 cells. Metabolomics analysis showed that the treatment with CA affected the intracellular levels of glutathione. Elevated levels of GSH provided additional evidence to transcriptomic results regarding chemopreventive response of cells to CA treatment. Moreover, the Foodomics approach was useful to establish the links between decreased levels of N-acetylputrescine and its degradation pathway at the gene level. The findings from this work and the predictions based on microarray data will help explore novel metabolic processes and potential signaling pathways to further elucidate the effect of CA in colon cancer cells. © 2014 American Chemical Society. Source

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