184 research outputs found
>Autentificación de Aceite de Oliva>: Problemas y posibles soluciones.
Los aspectos a autentificar en los aceites son cada vez más complicados. Las adulteraciones y sus posibles soluciones son cada vez más sofisticadas. La tendencia actual es la combinación de cromatografía y espectroscopía con la Quimiometría.
El aceite de oliva virgen ha llegado a ser un alimento global. En consecuencia los límites legales de parámetros químicos deberían revisarse tras un estudio exhaustivo de aceites incluyendo los nuevos países productores y todas las variedades. Se necesitan
bases de datos y usar procedimientos matemáticos.
Los métodos basados en hechos casuales son el gran problema de hoy.
La detección de aceites desodorizados, aceite de aguacate, y de avellana, están entre los mayores desafíos actuales.Peer Reviewe
Differentiation Between Ripening Stages of Iberian Dry-Cured Ham According to the Free Amino Acids Content
In this paper, the differentiation of three ripening stages, postsalting, drying, and cellar, of Iberian dry-cured ham has been carried out according to their free amino acids contents. Eighteen L-amino acids, alanine, 2-aminobutanoic acid, aspartic acid, cysteine, glutamine, glycine, histidine, hydroxyproline, isoleucine, leucine, lysine, methionine, phenylalanine, proline, serine, threonine, tyrosine, and valine have been determined by gas chromatography with derivatization with N,O-bis(trimethylsilyl)-trifluoroacetamide. Gas chromatography-mass spectrometry was used to confirm the presence of the eighteen amino acids in the ham samples, and gas chromatography using a DB-17HT column and flame ionization detector was used for quantitative determination. Extraction with a mixture methanol-acetonitrile has been carried out, achieving recoveries in the range 52-164%. Methimazole was used as internal standard. Limits of detection ranged between 7.0 and 611.7 mg·kg-1. Free amino acids have been used as chemical descriptors to differentiate between the ripening stages. Principal component analysis and linear discriminant analysis have been used as chemometric techniques, achieving complete differentiation between the ripening stages. Alanine, tyrosine, glutamine, proline, 2-aminobutanoic acid, cysteine, and valine were the most differentiating amino acids.Junta de Andalucía the project P09-AGR-0478
Safety of permanent pacemaker implantation: a prospective study
Although pacemaker implantation is considered to be low risk, it is not exempt from complications and technical failures during the procedure, both in the short and long term, and the complications that such patients may present remain unknown. The aim has been to analyze the complication rates associated with permanent pacing and to identify if these differ between patients with or without previous antithrombotic therapy. We used a prospective, single center, observational study of 310 adult patients with indications of permanent pacing. They were hospitalized from 1 January to 31 December 2014 and followed up for 6 months after the pacemaker implant. The participants were distributed into two groups according to the antithrombotic therapy prior to the implant. The most frequent major complications were pneumothorax (3.87%) and lead dislodgement (8.39%), while superficial phlebitis (12.90%) and uncomplicated hematomas (22.58%) were presented as the most recurrent minor complications. Hematomas were the most frequent minor complication in the antithrombotic therapy cohort, and shoulder pain was reported as the most recurrent minor complication in the non-exposed group. Finding out about complications in pacemaker implants enables a complete view of the process, and hence the prioritization of actions aimed at improving safety and reducing associated risks
Fatty acid and triacylglycerol composition of the subcutaneous fat from iberian pigs fattened on the traditional feed: "montanera". Effect of anatomical location and length of feeding.
Cinética de la reacción de elaidización del ácido oléico durante la desodorización y/o refinación física industrial de las grasas comestibles
A detailed study has been made of cis-trans isomerization of the oleic acid in the discontinuous physical refining of olive, soybean and sunflower oils in pilot plant of 250 Kg using nitrogen as stripping gas in place of steam. In each experimental assay, the expression of the analytical results have been made as molar fraction of different isomers of the acid 18:1: 18:1(9c), 18:1(9t), 18:1(w7c). The order of the reaction of formation of elaidic acid has been studied (zero or can be considered zero for the time taken in an industrial deodorization and/or physical refining, five hours). The kinetic constants “specific rate”, “activation energy” and “response factor” were determined. The analytical method used (GLC of the methyl esters and determination molar fraction) is appropriate for direct application of results in edible fats industry.Se estudia la isomerización cis trans del ácido oléico durante la refinación física discontinua de los aceites de girasol, oliva y soja en planta piloto de 250 Kg de carga usando nitrógeno como gas de arrastre en lugar de vapor de agua. Para cada uno de los ensayos realizados con los diferentes aceites, los resultados se han expresado en fracciones molares de los distintos isómeros del 18:1. Se ha determinado el orden de formación del ácido elaídico (cero o puede ser considerado cero en el periodo de tiempo que dura una refinación física, cinco horas como máximo), y los valores de las constantes de velocidad, energía de activación y factor de frecuencia. El método analítico utilizado (cromatografía de gases de los ésteres metílicos y determinación de las fracciones molares) es adecuado para poder aplicar los resultados obtenidos en las industrias del sector de refinación de aceites comestibles
Different fattening systems of iberian pig according to 1-alkene hydrocarbon content in the subcutaneous fat
Mechanical Properties of New Ceramic Materials Obtained from Granular Solid Residuals Coming from Mines and Diatomaceous Earth
Application of artificial neural networks to determine the authentication of fattening diets of iberian pigs according to their triacylglycerols profile
Valorization of Tomato Processing by-Products: Fatty Acid Extraction and Production of Bio-Based Materials
A method consisting of the alkaline hydrolysis of tomato pomace by-products has been optimized to obtain a mixture of unsaturated and polyhydroxylated fatty acids as well as a non-hydrolysable secondary residue. Reaction rates and the activation energy of the hydrolysis were calculated to reduce costs associated with chemicals and energy consumption. Lipid and non-hydrolysable fractions were chemically (infrared (IR) spectroscopy, gas chromatography/mass spectrometry (GC-MS)) and thermally (differential scanning calorimetry (DSC), thermogravimetric analysis (TGA)) characterized. In addition, the fatty acid mixture was used to produce cutin-based polyesters. Freestanding films were prepared by non-catalyzed melt-polycondensation and characterized by Attenuated Total Reflected-Fourier Transform Infrared (ATR-FTIR) spectroscopy, solid-state nuclear magnetic resonance (NMR), DSC, TGA, Water Contact Angles (WCA), and tensile tests. These bio-based polymers were hydrophobic, insoluble, infusible, and thermally stable, their physical properties being tunable by controlling the presence of unsaturated fatty acids and oxygen in the reaction. The participation of an oxidative crosslinking side reaction is proposed to be responsible for such modifications.Andalusian Regional Government P11-TEP-7418Spanish Ministerio de Economía y Competitividad AGL2015-65246-R and AGL2017-83036-RFondo Europeo de Desarrollo Regional (FEDER) AGL2015-65246-R and AGL2017-83036-
- …