Estudio comparativo del fraccionamiento de los carbohidratos de la miel mediante tratamiento con carbón activo y levaduras para la detección de adulteraciones

Recientemente se ha descrito la utilidad de los anhídridos de difructosa (DFAs) como buenos marcadores para la detección de adulteraciones de miel con jarabes de alto contenido en fructosa (HFCS) y de azúcar invertido (IS). Sin embargo, para la detección de estos compuestos es necesario realizar un fraccionamiento previo de los carbohidratos de estas muestras, dado que la alta concentración de monosacáridos (glucosa y fructosa) presentes en la miel dificulta el análisis de los compuestos minoritarios. Por tanto, el objetivo de este trabajo se basó en la comparación de un tratamiento con levaduras propuesto con anterioridad y un fraccionamiento con carbónactivo para eliminar la fracción de monosacáridos,concentrando así los compuestos minoritarios de la miely en concreto los DFAs presentes en muestras adulteradas.Se llevó a cabo la optimización de dichos métodos para conseguir el mayor enriquecimiento en DFAs comprobándose que ambos son útiles para la detección de adulteraciones de miel de hasta un 5% de HFCS e IS

Chemical modification of titanium precursor to obtain stable silica-titania sol: acetylacetone

[ES] La técnica Sol-Gel se ha utilizado para sintetizar una serie de sistemas multicomponentes, entre ellos SiO2 – TiO2. El mayor problema en la obtención de geles multicomponentes estables es la desigual velocidad de hidrólisis y condensación que presentan los alcóxidos precursores de los cationes de interés. En este trabajo se muestra cómo adicionando acetilacetona, acacH, al sistema TEOS – Ti(OBu)4 – H2O se puede obtener un sol estable. Se tomaron diferentes concentraciones de los precursores de silicio y titanio y una sola concentración de acacH. Se utilizó espectroscopia infrarroja, FTIR, para identificar los grupos funcionales presentes en el sistema y además se midió regularmente la viscosidad para determinar cualitativamente el avance de la policondensación del sistema.[EN] Sol-gel processing has become a well established technique for producing ceramic powders or glasses. This processing has been utilized to synthesize several interesting systems, e.g. the SiO2 – TiO2 system. A major concern in the stable multicomponent geles is that the hydrolysis and condensation velocities are diferent for each precursor, TEOS and Ti(OBu)4 in this work. The chemical control of these reactions is currently performed by adding complexing reagents that react with metal alkoxides at a molecular level, giving rise to new molecular precursors of different structure, reactivity and functionanality. This paper shows that stable TEOS – Ti(OBu)4 – H2O sol can be reproducibly prepared in the presence of acetylacetone. We shall then show that the acac behaves as a ligand, directly bonded to the titanium ion. Thus the formation of precipitate is avoided. Infra-red spectroscopy (FTIR) and viscosity measures were used to demostrated this behaviour of the system.Este trabajo fue financiado a través de los proyectos COLCIENCIAS N° 1103-05-605-93 y VRI-Universidad del Cauca N° 752. Agradecemos a Ecopetrol-ICP la colaboración prestada con los estudios de espectroscopia infrarroja y a la red CyTED VIII.E la ayuda económica y técnica gracias a la cual A. Mafla pudo realizar su pasantía en el ICVCSIC de Madrid-España.Peer reviewe

Characterization of goat colostrum oligosaccharides by nano-liquid chromatography on chip quadrupole time-of-flight mass spectrometry and hydrophilic interaction liquid chromatography-quadrupole mass spectrometry

A detailed qualitative and quantitative characterization of goat colostrum oligosaccharides (GCO) has been carried out for the first time. Defatted and deproteinized colostrum samples, previously treated by size exclusion chromatography (SEC) to remove lactose, were analyzed by nanoflow liquid chromatography–quadrupole-time of flight mass spectrometry (Nano-LC-Chip–Q-TOF MS). Up to 78 oligosaccharides containing hexose, hexosamine, fucose, N-acetylneuraminic acid or Nglycolylneuraminic acid monomeric units were identified in the samples, some of them detected for the first time in goat colostra. As a second step, a hydrophilic interaction liquid chromatography coupled to mass spectrometry (HILIC-MS) methodology was developed for the separation and quantitation of the main GCO, both acidic and neutral carbohydrates. Among other experimental chromatographic conditions, mobile phase additives and column temperature were evaluated in terms of retention time, resolution, peak width and symmetry of target carbohydrates. Narrow peaks (wh: 0.2–0.6 min) and good symmetry (As: 0.8–1.4) were obtained for GCO using an acetonitrile:water gradient with 0.1% ammonium hydroxide at 40 ◦C. These conditions were selected to quantify the main oligosaccharides in goat colostrum samples. Values ranging from 140 to 315 mg L−1 for neutral oligosaccharides and from 83 to 251 mg L−1 for acidic oligosaccharides were found. The combination of both techniques resulted to be useful to achieve a comprehensive characterization of GCO.This work has been funded by Junta de Andalucía (project AGR2011-7626), CSIC (project i-link0827), Comunidad Autónoma de Madrid (Spain) and European funding from FEDER program (AVANSECAL-CM S2013/ABI-3028) and Fundación Ramón Areces. This work was also supported by the UC Davis RISE program and the National Institutes of Health awards R21AT006180, R01AT007079, R01AT008759-02.Peer reviewe

Comparative Genomic Analysis of Human Fungal Pathogens Causing Paracoccidioidomycosis

Paracoccidioides is a fungal pathogen and the cause of paracoccidioidomycosis, a health-threatening human systemic mycosis endemic to Latin America. Infection by Paracoccidioides, a dimorphic fungus in the order Onygenales, is coupled with a thermally regulated transition from a soil-dwelling filamentous form to a yeast-like pathogenic form. To better understand the genetic basis of growth and pathogenicity in Paracoccidioides, we sequenced the genomes of two strains of Paracoccidioides brasiliensis (Pb03 and Pb18) and one strain of Paracoccidioides lutzii (Pb01). These genomes range in size from 29.1 Mb to 32.9 Mb and encode 7,610 to 8,130 genes. To enable genetic studies, we mapped 94% of the P. brasiliensis Pb18 assembly onto five chromosomes. We characterized gene family content across Onygenales and related fungi, and within Paracoccidioides we found expansions of the fungal-specific kinase family FunK1. Additionally, the Onygenales have lost many genes involved in carbohydrate metabolism and fewer genes involved in protein metabolism, resulting in a higher ratio of proteases to carbohydrate active enzymes in the Onygenales than their relatives. To determine if gene content correlated with growth on different substrates, we screened the non-pathogenic onygenale Uncinocarpus reesii, which has orthologs for 91% of Paracoccidioides metabolic genes, for growth on 190 carbon sources. U. reesii showed growth on a limited range of carbohydrates, primarily basic plant sugars and cell wall components; this suggests that Onygenales, including dimorphic fungi, can degrade cellulosic plant material in the soil. In addition, U. reesii grew on gelatin and a wide range of dipeptides and amino acids, indicating a preference for proteinaceous growth substrates over carbohydrates, which may enable these fungi to also degrade animal biomass. These capabilities for degrading plant and animal substrates suggest a duality in lifestyle that could enable pathogenic species of Onygenales to transfer from soil to animal hosts.National Institute of Allergy and Infectious Diseases (U.S.)National Institutes of Health. Department of Health and Human Services (contract HHSN266200400001C)National Institutes of Health. Department of Health and Human Services(contract HHSN2722009000018C)Brazil. National Council for Scientific and Technological Developmen

Mortality and pulmonary complications in patients undergoing surgery with perioperative SARS-CoV-2 infection: an international cohort study

Background: The impact of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) on postoperative recovery needs to be understood to inform clinical decision making during and after the COVID-19 pandemic. This study reports 30-day mortality and pulmonary complication rates in patients with perioperative SARS-CoV-2 infection. Methods: This international, multicentre, cohort study at 235 hospitals in 24 countries included all patients undergoing surgery who had SARS-CoV-2 infection confirmed within 7 days before or 30 days after surgery. The primary outcome measure was 30-day postoperative mortality and was assessed in all enrolled patients. The main secondary outcome measure was pulmonary complications, defined as pneumonia, acute respiratory distress syndrome, or unexpected postoperative ventilation. Findings: This analysis includes 1128 patients who had surgery between Jan 1 and March 31, 2020, of whom 835 (74·0%) had emergency surgery and 280 (24·8%) had elective surgery. SARS-CoV-2 infection was confirmed preoperatively in 294 (26·1%) patients. 30-day mortality was 23·8% (268 of 1128). Pulmonary complications occurred in 577 (51·2%) of 1128 patients; 30-day mortality in these patients was 38·0% (219 of 577), accounting for 81·7% (219 of 268) of all deaths. In adjusted analyses, 30-day mortality was associated with male sex (odds ratio 1·75 [95% CI 1·28–2·40], p\textless0·0001), age 70 years or older versus younger than 70 years (2·30 [1·65–3·22], p\textless0·0001), American Society of Anesthesiologists grades 3–5 versus grades 1–2 (2·35 [1·57–3·53], p\textless0·0001), malignant versus benign or obstetric diagnosis (1·55 [1·01–2·39], p=0·046), emergency versus elective surgery (1·67 [1·06–2·63], p=0·026), and major versus minor surgery (1·52 [1·01–2·31], p=0·047). Interpretation: Postoperative pulmonary complications occur in half of patients with perioperative SARS-CoV-2 infection and are associated with high mortality. Thresholds for surgery during the COVID-19 pandemic should be higher than during normal practice, particularly in men aged 70 years and older. Consideration should be given for postponing non-urgent procedures and promoting non-operative treatment to delay or avoid the need for surgery. Funding: National Institute for Health Research (NIHR), Association of Coloproctology of Great Britain and Ireland, Bowel and Cancer Research, Bowel Disease Research Foundation, Association of Upper Gastrointestinal Surgeons, British Association of Surgical Oncology, British Gynaecological Cancer Society, European Society of Coloproctology, NIHR Academy, Sarcoma UK, Vascular Society for Great Britain and Ireland, and Yorkshire Cancer Research

Synthesis of oligosaccharides derived from stachyose hydrolysis by pectinex ultra SP-L

Resumen del póster presentado al XII Scientific Meeting of the Spanish Society of Chromatography and Reated Techniques (Reunión Científica de la Sociedad Española de Cromatografía y Técnicas Afines) celebrado en Tarragona del 14 al 16 de noviembre de 2012.a-Galactosides are derivatives of sucrose that consist of galactose residues linked by a-(1-6) linkages to the glucose moiety. These oligosaccharides are found abundantly in grain legumes and their consumption is associated with the production of flatulence. However, they might be used as a prebiotic growth substrate for intestinal bacteria because they pass undigested to the colon. Several studies provide convincing evidence that a-galactosides have beneficial effects on the survival of different bifidobacteria strains. Raffinose and stachyose are industrially available in large amounts as a by product from the production of soy protein isolate, and they seem to be a promising raw material to manufacture of new oligosaccharides. The relatively inexpensive commercial enzyme preparation Pectinex Ultra SP-L (Pectinex), produced by Aspergillus aculeatus, has been shown to contain fructosyl transferase activity and therefore, it could be used as a catalyst in the large-scale production of stachyose-derived oligosaccharides with improved prebiotic properties. The objective of this work has been to investigate in more detail the fructosyl transferase activity from A. aculeatus of the commercial enzymatic preparation Pectinex during stachyose hydrolysis. Enzymatic synthesis of oligosaccharides from stachyose using Pectinex was carried out under different reaction conditions such as temperature (50, 60, and 70 °C), pH (3.5, 4.5, 5.5, 6.5, and 7.5), stachyose concentration (100, 300, and 600 g/L), enzyme concentration (17, 34, and 78 U/ml), and time up to 24 h. Purification of the reaction mixtures was performed following the method described by Morales et al. The enriched fraction was characterized by matrixassisted laser desorption/ion1zation time of flight mass spectrometry (MALDI-TOF-MS). Mass spectra were obtained over the m/z range 100-1500. Analysis of carbohydrates was performed by gas chromatography (GC) using a flame ionization as detector (FID). The trimethylsilyl oximes of mono-, di-, and oligosaccharides were resolved using a 8 m x 0.25 mm x 0.25 J.Jm film fused silica capillary column coated with CP-SIL 5CB (methyl silicone). The oven temperature was programmed from 150 to 165 oc at 3 °C/min, then at 5 °C/min to 340ºC and held at this temperature for 10 min. Quantitative analysis was carried out by the internal standard method. The amount of remaining stachyose and the yield of oligosaccharides in the reaction mixtures were expressed as weight percentage of total carbohydrate content. Different oligosaccharides from DP2 to DP8 were formed during stachyose hydrolysis by fructosyltransferase activity of A. aculeatus. Galactosyl-melibiose (DP3) was synthesized as a result of fructosidase activity, whereas fructosyl-stachyose (DP5) and difructosyl-stachyose (DP6) were formed as a consequence of the fructosyl transferase activity of the enzyme preparation. Temperature, pH, substrate and enzyme concentrations were varied to select the optimum conditions for tri- or oligosaccharide synthesis. The optimal reaction conditions for the synthesis of penta- and hexasaccharides were 60°C, pH 5.5, 600 mg/ml of stachyose, and 34 U/ml of enzyme during 3h. However. to obtain the maximum yield of galactosyl-melibiose (67%), the assays should be carried out at 60 °C and pH 5.5, using 100 mg/ml of stachyose and 34 U/ml of enzyme during 24 h since it was a very stable to hydrolysis. In conclusion, stachyose could be used as a substrate for the enzymatic synthesis of new oligosaccharides that may open new opportunities in the development of future prebiotics.This work has been financed under a R+D program of the Spanish Ministry of Science and Innovation, Consolider Ingenio 2010 (FUN-C-FOOD): CSD 2007-00063; R + D program of the Comunidad de Madrid, project ALIBIRD 2009/AGR-1469 ;R + D program of the Comunidad de Castilla-La Mancha POII10-0178-4685 and IBEROFUN P109AC0302 (CYTED).Peer Reviewe

Optimization of microwave assisted extraction of Mentha sp. bioactives

Trabajo presentado a la XV Reunión Científica de la Sociedad Española de Cromatografía y Técnias Afines- SECyTA 2015 celebrada en Castellón de la Plana del 28 al 30 de octubre de 2015Despite the existence of a wide variety of food preservation techniques, the microbial contamination continues to be an important problem that affects not only food quality but also food security [1]. Diverse formulations based on plant extracts/essential oils have been developed as a healthier alternative to synthetic antimicrobials [1, 2]. Among them, those arising from different Mentha species have been reported as highly effective [3]. Microwave assisted extraction (MAE) is a fast and efficient emergent technique which has gained a great acceptance for the extraction of plant bioactives [4]. To the best of our knowledge, MAE has not yet been applied for obtaining antimicrobials from Mentha sp. After selection of optimal extraction solvent, the effect of different factors (sample weight: 0.75-1.5 g, extraction temperature: 50-100 °C, and extraction time: 5-30 min) on recovery of compounds with antimicrobial activity was evaluated by a Box-Behnken experimental design. Prior to quantitation, extracts were comprehensively characterized by using different techniques: (i) Extracts were directly analyzed or derivatized (trimethylsilyl oximes) for their Gas Chromatography-Mass Spectrometry (GC-MS) analysis using a methyl polysiloxane column (30m x 0.25mm x 0.25μm). (ii) After filtration, extracts were analyzed by Liquid Chromatography-Quadrupole Time of Flight Mass Spectrometry (LC-QToF MS), using a reversed phase C18 column (100 x 2 mm, 3 μm, 100 Å) and a binary gradient of methanol and water, both phases acidulated with 0.1% acetic acid. The optimized MAE method was applied for extraction of bioactives from different Mentha species (M. spicata, M. rotundifolia, M. piperita, M. pulegium, etc). MAE is shown as an advantageous technique for obtaining extracts of Mentha sp. with antimicrobial activity of application in the food industry. [1] C.A. Phillips, K. Laird, S.C. Allen, Food Res. Int. 47 (2012) 310-314. [2] M.F. Andrés, A. González-Coloma, J. Sanz, P. Sainz, Phytochem. Rev. 11 (2012) 371-390. [3] R.I. Moldova et al., Dig. J. Nanomater. Bios. 9 (2014) 559-566. [4] J. Azmir et al., J. Food Eng. 117 (2013) 426-436Comunidad Autónoma de Madrid (Spain) and European funding from FEDER program (AVANSECAL-CM S2013/ABI-3028).Peer reviewe