Plaza M.,Institute of Food Science Research |
Santoyo S.,Institute of Food Science Research |
Jaime L.,Institute of Food Science Research |
Avalo B.,University Simon Rodriguez |
And 5 more authors.
LWT - Food Science and Technology | Year: 2012
Chlorella vulgaris has been referred as a potential source of bioactive compounds (carotenoids and fatty acids). In this work, the ability of an environmentally friendly extraction technique such as Pressurized Liquid Extraction (PLE) and a traditional extraction technique such as Ultrasound-Assisted Extraction (UAE) to obtain functional compounds from C. vulgaris, at analytical scale, has been demonstrated. Seeked bioactivities were antioxidant and antimicrobial, for their interest in the food industry. Therefore, a methodology including analytical extraction, in-vitro assays and chemical characterization via HPLC-DAD and GC-MS has been used to determine the interest of Chlorella as a source of functional food ingredients. Results demonstrated that PLE provide higher yields than UAE while similar bioactivities were obtained. Important concentration of carotenoids (lutein, neoxanthin, β-carotene, etc.), chlorophylls, sterols, phytols, and fatty acids (among others) have been found in Chlorella extracts that could be correlated to the observed biological activity. © 2011 Elsevier Ltd.
Evaluation of the filtration and ingestion rates of dendrocephalus spartaenovae (Crustacea: Anostraca: Thamnocephalidae) with pseudokirchneriella subcapita y chlorella vulgaris in laboratory conditions [Evaluación de las tasas de filtración e ingestión de dendrocephalus spartaenovae (Crustacea: Anostraca: Thamnocephalidae) con pseudokirchneriella subcapita y chlorella vulgaris en condiciones de laboratorio]
Brito D.,Sanidad Animal |
Brito R.,University Simon Rodriguez |
Pereira G.,Central University of Venezuela
Interciencia | Year: 2010
In the six species of fairy shrimps (Anostraca) recorded in Venezuela, only a few life history parameters have been determined for Dendrocephalus geayi y Thamnocephalus venezuelensis. The species Dendrocephalus spartaenovae Margalef, 1961 has a high potential as live food and for industrial purposes, and could be an alternative to Artemia cysts, which are expensive and sometimes hard to find. The objective of this study was to generate information about the nutritional behavior of D. spartaenovae in laboratory conditions and closed systems. Filtration and ingestion rates were determined in different concentrations of a mixed culture of the unicellular algae Pseudokirchneriella subcapita (Printz, 1914) y Chlorella vulgaris Beijerinck, 1980 on three animal groups aged 3-4, 10-11 and 17-18 days old. The filtration and ingestion rates were determined according to sex, animal density and light conditions on organisms 17- 18 days old fed with 5·105 cel/ml. Filtration rates decreased as the amount of food increased; while ingestion rates showed an inverse response. Sex conditions in older animals did not affect filtration and ingestion rates. The filtration rates did not show significant differences with regard to light conditions, but the highest food consumption (2,761,574 cel/ind/h) was recorded during the day and the lowest (1,465,278 cel/ind/h) at nighttime. Population densities over 2 ind/200ml caused a detriment in the nutritional behavior.
Hay intake and milk production in dual purpose cows suplemented with multinutritional blocks [Consumo de heno y producción de leche en vacas doble propósito suplementadas con bloques multinutricionales]
Herrera A.M.,National Experimental University of Táchira |
Martinez N.,Central University of Venezuela |
Herrera P.,University Simon Rodriguez |
Colmenares O.,University Romulo Gallegos |
Birbe B.,University Simon Rodriguez
Zootecnia Tropical | Year: 2010
To evaluate the effect of the supplementation with multinutritional blocks (MB) on milk production, 20 dual purpose cows were used with breeding and 1 or 2 calving, in hilly area of the central plains of Venezuela. The experiment was carried with duration of 60 days of supplementation and 30 additional days of evaluation. A completely randomized design was used, with two groups: Control group (CG) (n=10): animals with ad libitum basal diet and Experimental group (EG) (n=10): animals with diet basal ad libitum plus MB. Sold milk and consumed by the calf were measured, and used to estimate total milk. As basal diet these animals were in paddocks with species like Cynodon nlemfuensis, Panicum maximun, Andropogon gayanus, Brachiaria arrecta and Dichanthium aristatum, and consumed milled hay of Cynodon nlemfuensis and crop residues of Sorghum bicolor in corrals. The chemical composition of the MB was: 29,6% of crude protein, 2,1% of ethereal extract, 16,9% of DNF, 9,9% of calcium and 2,5% of phosphorus. The average of MB intake was 67,92± 21,41 g.100 kg-1 live weight. The effect of treatment was significant in the milk consumed by the calf (P<0,01), with EG=1,17 ± 0,34 and CG= 0,75 ± 0,36 kg; sold and total milk did not show significant differences between treatments (P>0,05). A tendency exists to the increase in the milk production in supplemented cows with multinutritional blocks in these conditions, evidenced in the consumption of milk by the calf.
Phidotricha erigens Ragonot, 1888 (Lepidoptera: Pyralidae), causing damage in Agave cocui Trelease, in Falcon State, Venezuela. Some aspects of its biology and natural control [Phidotricha erigens Ragonot, 1888 (Lepidoptera: Pyralidae), causando daño en Agave cocui Trelease, en el estado Falcón, Venezuela. Algunos aspectos de su biología y su control natural]
Velazquez J.,Francisco de Miranda National Experimental University |
Garcia J.L.,University Simon Rodriguez |
Romero Y.,Francisco de Miranda National Experimental University |
Medina M.,Francisco de Miranda National Experimental University
Entomotropica | Year: 2010
A research was carried out for the identification and the determination of some aspects of the biology and the natural control of a lepidopteran larva that causes damage in the inflorescences, bulbs and leaves of Agave cocui. Between April 2001 and April 2008 visits were carried out to areas with high density of A. cocui in Falcon State, and infested vegetable material was collected and brought to the laboratory where the damaging lepidopteran and its natural ennemies were reared under semi-controlled conditions, at a temperature 27 ± 3°C, relative humidity of 70 ± 8 % and a photoperiod 12:12. Duration of different phases and the number of larval instars were determined and the number of eggs produced per female, as well as the identification of the main natural enemies, were established. For the first time in Venezuela, Phidotricha erigens Ragonot, 1888 (Lepidoptera: Pyralidae) is mentioned as a plague of A. cocui. The adults passed average of 6.2 days (male) and 5.9 days (female), females placed an average of 18.5 eggs. The larvae hatch in about 4.2 days, they pass through five stadiums with a duration of 3.8, 3.7, 3.8, 5.4 and 5.5 days for the I, II, II, IV, and V instar respectively, being the average duration larval phase 19.7 days, and pupae 11.2 days. P erigens is controlled naturally by the parasitic hymenopterans, Apanteles sp., Copidosoma sp., Eiphosoma sp., Hymenochaonia sp. and Euplectrus sp. We detected Bramesa sp. and Perilampus sp. emerging from the pupae of Apanteles sp. © 2010, Sociedad Venezolana de Entomología.
Detection of listeria monocytogenes in white cheese by polymerase chain reaction (PCR) [Detección de listeria monocytogenes en queso blanco criollo, mediante la reacción en cadena de la polimerasa (PCR)]
Ramirez Merida L.G.,University Simon Rodriguez |
De Salim A.M.,University Simon Rodriguez |
Alfieri Graterol A.Y.,University Simon Rodriguez |
Gamboa O.,University Simon Rodriguez
Archivos Latinoamericanos de Nutricion | Year: 2010
The Polymerase Chain Reaction, known as PCR, is a method to replicate thousands of times within a few hours and in vitro, small amounts of DNA. The application of rapid and sensitive methods to detect Listeria monocytogenes in cheese samples, allow a better microbiological control of the production process. PCR was applied to 30 samples of of white cheese, from Valencia, Carabobo State. It was detected PCR specificity and sensitivity by using the control strain Listeria monocytogenes 446. DNA extraction according to the methodology described by Torres et al., Molecular weight marker 100 base pairs. Were used: four primers hlyA gene of listeriolysin O; L1/U1 primers for 938 bp band and LF / LR 750 bp band hlyA gene. EpiInfo Statistical V6 to match observations in gels, by Kappa coefficient (K). Results: 8 out of 30 cheese samples analyzed showed presumptive growth of Listeria spp in PALCAM Agar. Two of the samples not belonged to the genus Listeria, in the 6 remaining sample confirmation tests showed that: 2 were L. monocytogenes, 3 L. ivanovii and 1 L. seeligeri. In PCR 2 samples were positive for L. monocytogenes by amplify the 938 bp band for Listeria and 750 bp band for the species monocytogenes. We concluded that PCR was highly specific and sensitive to L. monocytogenes, taking advantage of PALCAM agar to detect the presence of the pathogen specifies a relatively short time.
Trujillo I.,University Simon Rodriguez |
Rivas M.,Simon Bolivar University of Venezuela |
Castrillo M.,Simon Bolivar University of Venezuela
Journal of Plant Interactions | Year: 2013
Our hypothesis was that recovery responses (RI and RII) upon rehydration, after 1 and 8 d of moderate (WDI) and severe water deficit (WDII), are evidence of tolerance in two commercial bean cultivars, Tacarigua (T cv) and VUL-73-40 (V cv). Recovery of leaf water (Ψw) and osmotic potentials (Ψs), and relative water content (LRWC), showed strong dependence on soil water potential (sΨw) followed by protein content; recovery connection between stomatal conductance and soil Ψw is showed. Chlorophyll (a + b), Ribulose-1,5-bisphosphate carboxylase oxygenase (Rubisco) activity, dry biomass (DM), and leaf area (LA) recovery were sensitive to WD intensity. Specific leaf area (SLA) and leaf density (D) recovery were less dependent on WD intensity and in time-dependent manner; V cv recovery was slower, showed faster recovery of Rubisco activity and DM due to slower recovery in SLA and D, which promoted it. Rubisco activity presented correlations with LRWC and Ψw at moderate and severe WD in both cultivars, and significant correlation with Ψs was observed in V cv. We conclude that recovery after rehydration reveals intrinsic tolerance to WD, due to an integration of metabolic and structural interactions, in responses to leaf water status components. © 2013 Copyright Taylor and Francis Group, LLC.
Splenectomy effects on the total number leukocytes and total serum proteins total in calves Bos taurus [Efectos de la esplenectomía sobre el número total de leucocitos y proteínas séricas totales en becerros Bos taurus]
Espinoza E.,University Simon Rodriguez |
Alvarez A.,Instituto Nacional Of Investigaciones Agricolas Inia
Zootecnia Tropical | Year: 2012
The aim of this study was to perform a comparative study of the total number of leukocytes (TLN) and total serum proteins (TSP) in. Bos Taurus calves splenectomized vs non splenectomized, to serve as multipliers haemotropic agents. Six were splenectomized for conventional surgical methods and the remaining three were used as controls. The variables determinations were carried out during an experimental lapse of five weeks, using the hemocytometer for the obtaining of the TLN and commercial colorimetric method for analysis of SPT and its components (albumin, globulins and ratio A:G). The data grouped in means and they were analyzed of the non-parametric "U" Mann-Whitney. The comparison between means did not show any statistical differences. The findings did not allow definitive conclusions about variables studied. The ratio A:G (0.6) suggested the production of antibodies in animals splenectomized.
Description of a new species of isolia förster (Hymenoptera Platygastridae) from the Iberian Northeast [Descripción de una nueva especie de Isolia Förster (Hymenoptera: Platygastridae) del Nordeste Ibérico]
Garcia R.J.L.,University Simon Rodriguez |
Pujade-Villar J.,University of Barcelona
Entomotropica | Year: 2010
We describe a new species of Isolia Förster. Isolia santosi sp. n. is described on the basis of 166 specimens collected at the Parque Natural de Sant Llorenç del Munt i Serra de l'Ibac, (Catalonia, Spain). Diagnostic characters are given that set this species apart form other in the genus.