Technological Institute of Veracruz

Veracruz, Mexico

Technological Institute of Veracruz

Veracruz, Mexico
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Ledesma-Escobar C.A.,University of Cordoba, Spain | Ledesma-Escobar C.A.,Technological Institute of Veracruz | Priego-Capote F.,University of Cordoba, Spain | Robles-Olvera V.J.,Technological Institute of Veracruz | Luque de Castro M.D.,University of Cordoba, Spain
Food Chemistry | Year: 2017

Citrus possess a large number of bioactive compounds mainly studied in ripe fruits. Few studies have focused on evolution of metabolites during fruit growth. In this study, fruits were sampled from weeks 1–14 of the ripening process. Polar extracts were obtained from all collected samples and analysed by liquid chromatography–tandem mass spectrometry. Analysis of variance applied to the dataset indicated that the relative concentration of 394 out of 423 molecular entities changed significantly during maturation. Principal component analysis showed a clear separation among samples from different weeks and revealed the main compounds responsible for differentiation. Additionally, 72 metabolites were tentatively identified and changes in their relative concentration during growth were individually analysed. The observed trends in relative concentrations of representative metabolites during the growth process are discussed. © 2017 Elsevier Ltd

Ledesma-Escobar C.A.,University of Cordoba, Spain | Feliciano Priego-Capote,University of Cordoba, Spain | Feliciano Priego-Capote,Technological Institute of Veracruz | De Castro M.D.L.,University of Cordoba, Spain
PLoS ONE | Year: 2016

Background Flavonoids have shown to exert multiple beneficial effects on human health, being also appreciated by both food and pharmaceutical industries. Citrus fruits are a key source of flavonoids, thus promoting studies to obtain them. Characteristics of these studies are the discrepancies among sample pretreatments and among extraction methods, and also the scant number of comparative studies developed so far. Objective Evaluate the effect of both the sample pretreatment and the extraction method on the profile of flavonoids isolated from lemon. Results Extracts from fresh, lyophilized and air-dried samples obtained by shaking extraction (SE), ultrasound-Assisted extraction (USAE), microwave-Assisted extraction (MAE) and superheated liquid extraction (SHLE) were analyzed by LC-QTOF MS/MS, and 32 flavonoids were tentatively identified using MS/MS information. ANOVA applied to the data from fresh and dehydrated samples and from extraction by the different methods revealed that 26 and 32 flavonoids, respectively, were significant (p<0.01). The pairwise comparison (Tukey HSD; p<0.01) showed that lyophilized samples are more different from fresh samples than from air-dried samples; also, principal component analysis (PCA) showed a clear discrimination among sample pretreatment strategies and suggested that such differences are mainly created by the abundance of major flavonoids. On the other hand, pairwise comparison of extraction methods revealed that USAE and MAE provided quite similar extracts, being SHLE extracts different from the other two. In this case, PCA showed a clear discrimination among extraction methods, and their position in the scores plot suggests a lower abundance of flavonoids in the extracts from SHLE. In the two PCA the loadings plots revealed a trend to forming groups according to flavonoid aglycones. Conclusions The present study shows clear discrimination caused by both sample pretreatments and extraction methods. Under the studied conditions, liophilization provides extracts with higher amounts of flavonoids, and USAE is the best method for isolation of these compounds, followed by MAE and SE. On the contrary, the SHLE method was the less favorable to extract flavonoids from citrus owing to degradation. © 2016 Ledesma-Escobar et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in anymedium, provided the original author and source are credited.

Ledesma-Escobar C.A.,University of Cordoba, Spain | Ledesma-Escobar C.A.,Technological Institute of Veracruz | Priego-Capote F.,University of Cordoba, Spain | Luque De Castro M.D.,University of Cordoba, Spain
Talanta | Year: 2016

A study on the key role of lemon sample pretreatment on the analytical results is here presented. The objective of the study was to analyze the differences between extracts obtained from lyophilized and air-dried samples - the most common sample pretreatment in citrus studies - in comparison to extracts from fresh samples. All the extracts were obtained with ultrasound assistance and analyzed by LC-QTOF MS/MS. The dataset, constituted by 74 tentative identified metabolites, was first evaluated by ANOVA, which showed significant differences in the concentration of 44 out of 74 metabolites (p≤0.01). Also, the pairwise mean comparison (Tukey HSD; p≤0.01) revealed that the concentration of metabolites in the extracts from fresh and air-dried samples was quite similar and differed from that in lyophilized samples. On the other hand, application of principal component analysis (PCA) showed a clear discrimination between pretreatments, explaining 86.20% of the total variability. The results of this study suggest that the main differences between extracts could be attributed to the effect of freezing or heating on metabolic pathways, and not only to thermolability of the compounds. © 2016 Elsevier B.V. All rights reserved.

Ledesma-Escobar C.A.,University of Cordoba, Spain | Ledesma-Escobar C.A.,Technological Institute of Veracruz | Luque de Castro M.D.,University of Cordoba, Spain
Trends in Food Science and Technology | Year: 2014

The first aim of this review is to show the present state of exploitation of residues from the citrus industries by: (i) discussing the way in which sampling and sample conditioning have been carried out, showing their deficiencies and giving solutions to them; (ii) commenting the designs for optimization of the steps of the analytical process and proposing new designs; (iii) showing the advantages and disadvantages of the different methods for extraction of high- and low-priced compounds from citrus and potential degradation they can undergo; (iv) emphasizing the shortcomings of conventional analytical equipment for identification and quantitation of the target compounds and proposing both cutting-edge analytical equipment and the way the provided data should be processed. To open a door to comprehensive exploitation of citrus residues is the final aim of this review. © 2014 Elsevier Ltd.

Peralta Pelaez L.A.,Technological Institute of Veracruz | Moreno-Casasola P.,Institute of Ecology AC | Lopez Rosas H.,National Autonomous University of Mexico
Marine and Freshwater Research | Year: 2014

Coastal dunes include several habitats, including dune lakes. These habitats are valuable environmental assets. We analysed the impact of the surrounding land use on plant species composition, vegetation structure and water quality of 15 dune lakes in the coast of Veracruz in the Gulf of Mexico. The physical and chemical characteristics were determined for water during both the dry and rainy seasons, and vegetation was sampled once. Ammonium, nitrate, orthophosphate and total phosphorus varied between seasons and among lakes. Multivariate analysis revealed a gradient from lakes in a good state (water and wetland vegetation) to degraded lakes. These lakes fall into two groups: the first one has five lakes with a higher nutrient content, and surrounded by land where livestock is pastured and sugarcane is grown. The vegetation of these lakes consists of a combination of aquatic plants and flood-tolerant grasses introduced to feed cattle (Cynodon dactylon, Pennisetum purpureum, Setaria geniculata). Oligotrophic and mildly eutrophic lakes are characterised by little human activity, and aquatic species predominate (Cabomba palaeformis, Nymphaea ampla, Acrostichum aureum). Rural activities such as sugarcane cultivation and cattle rearing are likely the main factors causing changes in water enrichment and affecting the composition and structure of wetland vegetation. Management measures should be implemented to recover these areas and prevent further deterioration. © CSIRO 2014.

Brito-de la Fuente E.,Kabi Innovation Center | Torrestiana-Sanchez B.,Technological Institute of Veracruz | Martinez-Gonzalez E.,Kabi Innovation Center | Mainou-Sierra J.M.,Kabi Innovation Center
Chemical Engineering Research and Design | Year: 2010

The impact of high-frequency cross-flow back-pulsing on microsieves permeation performance during the microfiltration of whole milk is described in this work. Silicon nitride microsieves (0.8μm rectangular) combined with a dynamic permeate cross-flow back-pulsing technique to control fouling were used. Results showed that the transmembrane pressure (TMPpos) and the back-pulsing frequency were the process variables that most influenced microsieves performance. Permeation rates in the range of 5000 up to 27,000Lh-1m-2 which are one order of magnitude higher than those reported for skim milk microfiltration were obtained depending on the process conditions selected. It was concluded that higher permeation rates are obtained when the back-pulse pressure, i.e., the negative TMP is set equal to the positive TMP, both at 150mBar and the back-pulsing frequency at 15Hz. © 2009 The Institution of Chemical Engineers.

Vargas-Garcia A.,Technological Institute of Veracruz | Torrestiana-Sanchez B.,Technological Institute of Veracruz | Garcia-Borquez A.,National Polytechnic Institute of Mexico | Aguilar-Uscanga G.,Technological Institute of Veracruz
Separation and Purification Technology | Year: 2011

The effect of grafting with fluoroalkylsilanes on microstructure, composition and surface and transport properties of alumina membranes having different pore sizes (0.2, 0.5 and 0.8 μm) was studied. Surface and transport properties were evaluated in terms of contact angle, adhesion work and hydrodynamic membrane pore response. Scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDXS) were employed to evidence the induced microstructure and composition changes after grafting. Contact angle higher than 90°, in addition to low work adhesion and surface tension values confirmed the hydrophobic character of all three membranes after chemical treatment. SEM analysis showed facetted alumina grains in unmodified membranes while grains with rounded edges appeared after grafting. This effect induced compaction on internal and intermediate layers mainly on the 0.2 μm membrane. The insertion of hydrophobic chains on the outer surface and the porous structure of membranes after grafting, were evidenced by detection of fluor in the active and internal structure of treated membranes as well as by increments on the Si/Al ratios followed by EDXS. In addition, water permeability drastically decreased and intrusion pressure rose, mainly on the membrane of lower pore size tested. Hydrodynamic membrane response indicated pore size reductions of 53%, 65% and up to 82% in 0.2, 0.5 and 0.8 μm grafted membranes, respectively. However, silane chains inserted inside of 0.5 and 0.8 μm membrane pores were apparently more susceptible to flow induced deformation, limiting the potential application of these membranes on the osmotic evaporation process. Results from grafted 0.2 μm alumina membrane during OE of clarified cane juice and model sucrose solution indicate that feed and brine layer resistances contribute in less than 10% while membrane resistance contribution to the total process resistance was around 90%. Results from this work indicate that applicability of grafted alumina membranes in the OE process might further improve by using 0.2 μm < dP < 0.5 μm average pore size membranes and/or by decreasing membrane thickness. © 2011 Elsevier B.V. All rights reserved.

Escudero N.,University of Alicante | Marhuenda-Egea F.C.,University of Alicante | Ibanco-Canete R.,University of Alicante | Zavala-Gonzalez E.A.,University of Alicante | And 2 more authors.
Metabolomics | Year: 2015

A combined chemometrics-metabolomics approach [excitation–emission matrix (EEM) fluorescence spectroscopy, nuclear magnetic resonance (NMR) and high performance liquid chromatography–mass spectrometry (HPLC–MS)] was used to analyse the rhizodeposition of the tritrophic system: tomato, the plant-parasitic nematode Meloidogyne javanica and the nematode-egg parasitic fungus Pochonia chlamydosporia. Exudates from M. javanica roots were sampled at root penetration (early) and gall development (late). EMM indicated that late root exudates from M. javanica treatments contained more aromatic amino acid compounds than the rest (control, P. chlamydosporia or P. chlamydosporia and M. javanica). 1H NMR showed that organic acids (acetate, lactate, malate, succinate and formic acid) and one unassigned aromatic compound (peak no. 22) were the most relevant metabolites in root exudates. Robust principal component analysis (PCA) grouped early exudates for nematode (PC1) or fungus presence (PC3). PCA found (PC1, 73.31 %) increased acetate and reduced lactate and an unassigned peak no. 22 characteristic of M. javanica root exudates resulting from nematode invasion and feeding. An increase of peak no. 22 (PC3, 4.82 %) characteristic of P. chlamydosporia exudates could be a plant ‘‘primer’’ defence. In late ones in PC3 (8.73 %) the presence of the nematode grouped the samples. HPLC–MS determined rhizosphere fingerprints of 16 (early) and 25 (late exudates) m/z signals, respectively. Late signals were exclusive from M. javanicaexudates confirming EEM and 1H NMR results. A 235 m/z signal reduced in M. javanica root exudates (early and late) could be a repressed plant defense. This metabolomic approach and other rhizosphere -omics studies could help to improve plant growth and reduce nematode damage sustainably. © Springer Science+Business Media New York 2014.

PubMed | University of Alicante and Technological Institute of Veracruz
Type: Journal Article | Journal: Journal of basic microbiology | Year: 2016

The effect of chitosan on growth of Trichoderma spp., a cosmopolitan genus widely exploited for their biocontrol properties was evaluated. Based on genotypic (ITS of 18S rDNA) characters, four isolates of Trichoderma were identified as T. pseudokoningii FLM16, T. citrinoviride FLM17, T. harzianum EZG47, and T. koningiopsis VSL185. Chitosan reduces radial growth of Trichoderma isolates in concentration-wise manner. T. koningiopsis VSL185 was the most chitosan tolerant isolate in all culture media amended with chitosan (0.5-2.0mgml(-1) ). Minimal Inhibitory Concentration (MIC) and Minimal Fungicidal Concentration (MFC) were determined showing that T. koningiopsis VSL185 displays higher chitosan tolerance with MIC value >2000gml(-1) while for other Trichoderma isolates MIC values were around 10gml(-1) . Finally, free fatty acid composition reveals that T. koningiopsis VSL185, chitosan tolerant isolate, displays lower linolenic acid (C18:3) content than chitosan sensitive Trichoderma isolates. Our findings suggest that low membrane fluidity is associated with chitosan tolerance in Trichoderma spp.

Ricano-Rodriguez J.,Technological Institute of Veracruz | Ramirez-Lepe M.,Technological Institute of Veracruz
Turkish Journal of Biology | Year: 2015

An intracellular nitrilase (Nit1) with cyanide-degrading activity was isolated from Trichoderma harzianum VSL291, cultivated on benzonitrile as the sole carbon source. Nit1 was purified to homogeneity by ion exchange and gel filtration chromatography with a recovery of 7.15% and a fold of 22.5. The molecular weight was estimated to be 47.7 kDa and the purified enzyme was sequenced with a system of liquid chromatography and mass spectrometry (LC-MS). The enzyme consists of 436 amino acids with a predicted molecular weight of 47.088 kDa. The sequence revealed conserved domains for a nitrilase super family such as putative active and binding sites and a Glu-Lys-Cys catalytic triad. Nit1 exhibited maximum activity (19.6 U mg –1) at 40 °C and a pH of 7.5. Nit1 had a strong inhibition in the presence of Al3+, Cu2+, Zn2+, and Ag+ ions and was able to degrade KCN completely at 0.02 mmol/L, 0.05 mmol/L, and 0.1 mmol/L in 15 min, 40 min, and 45 min, respectively. The effect on KCN (0.02 mmol/L) degradation was tested in the presence of Cu2+ and Ag+ ions (0.025 mmol/L to 1.0 mmol/L) and the enzymatic activity was not affected significantly at 0.025 mmol/L, 0.075 mmol/L, and 0.125 mmol/L concentrations. However, when both ions were combined, the activity of the enzyme decreased significantly. © TÜBİTAK.

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