Qualitat microbiològica dels productes vegetals frescos mínimament processats i desenvolupament de tecnologies de bioconservació mitjançant bacteris de l'àcid làctic

Food safety today is conditiones by the implementation of new Tecnologies for food preservation based on mild treatments and mínimum process, Novel foods, severe restrictions in the toxicològic profile of chemical preservatives, And the drastic limitation /prohibition of antibiotics, and as a consequence, by the New emergint pathogens or by the increase of classical food-borne pathogens. Biopreservatives appear within this context with strong expectations, because thei are safe microorganisms of ten isolated from foods, chemical compounds of natural origin -antimicrobial peptides and proteins, botanical extracts, enzymes- and sintetic compounds based on natural structures, but less toxic and more eficients, like the amtimicrobial peptides. Among the microbial biopreservatives, lactic acid bacteria have shown great possibilities in the preservation of cured meat products, ready to eat fresh fruit and vegetables, as well as to decrease microbial spoilage in food by products before processing for valorization. Our laboratory has performed an extense survey of the microbiological quality of fresh fruit and vegetables, and of ready-to-eat products, and have detect low levels, but significant of Salmonella sp., E. coli and Listeria spp., including L.monocytogenes, in retail markets and Supermarkets of Catalonia. Due to this reason, we started a project consisting of Developing application of lactic acid bacteria (LAB) obtained from these products, as biopreservatives. LAB were abundant in ready-to-eat fresh fruits and vegetables, specially in germinated seeds. From these products we obtained strains of Leuconostoc, Lactobacillus and Weissella, producing bacteriocins and with a Significant activity of control of L.monocytogenes in fresh apple and cut salad. Ather strains were efective in the inhibition of fungal rot during postharvest caused by Penicillium expansum

Recomendaciones de manipulación doméstica de frutas y hortalizas para preservar su valor nutritivo

El beneficio para la salud del consumo diario de al menos 5 raciones entre frutas y hortalizas está bien documentado. En España no se alcanzan los 600 gramos por persona y día que recomienda la Organización Mundial de la Salud (OMS) en sus objetivos de salud pública, por lo que es importante mejorar el acceso a estos alimentos, aprovechar su potencial nutritivo y salvar las barreras para su consumo. Los objetivos de este documento son: facilitar la toma de decisiones responsables con la salud; aprovechar al máximo el valor nutritivo de frutas y hortalizas; ayudar a salvar las barreras para su consumo e informar sobre cómo afecta la conservación, manipulación y cocinado domésticos a su valor nutritivo. Para minimizar la pérdida de nutrientes y mejorar su biodisponibilidad durante la manipulación de frutas y hortalizas, la Asociación para la promoción del consumo de frutas y hortalizas"5 al día" (España) recomienda: evitar almacenamientos prolongados en el refrigerador; aprovechar las capas y hojas exteriores; pelar y/o cortar el alimento justo antes de consumirlo; lavar las piezas enteras y trocearlas posteriormente; controlar el tiempo de remojo de las piezas cortadas; preferir técnicas de cocinado que no requieran contacto directo con el agua; a menor tiempo de cocción, menor pérdida de nutrientes; la fritura correcta conserva muy bien los nutrientes, aunque no debe abusarse de esta técnica; añadir un chorrito de vinagre o de zumo de limón al agua de cocción; aprovechar el agua de los vegetales cocidos para elaborar otros alimentos (ej.: salsas, sopas, purés, etc.), excepto la de acelgas, espinacas o remolacha. La Asociación"5 al día" recomienda aumentar el consumo de frutas y hortalizas, y considera que la pérdida de nutrientes durante su manipulación doméstica no debe entenderse como una barrera para su consumo.

Determination of the complexing capacity of synthetic and real wine for Zn using Absence of Gradients and Nerstian Equilibrium Stripping technique

The complexing capacity of synthetic (0.011 M tartrate in 13.5% ethanol) and real wine (Raimat Abadia) in titrations with added total Zn concentrations up to 0.03 M has been determined following the free Zn concentrations with AGNES (absence of gradients and Nernstian equilibrium stripping) technique. A correction to find the preconcentration factor or gain (Y1) really applied at each one of the ionic strengths reached due to Zn additions along the titration has been applied. The standard implementation of AGNES to real wine led to the observation of two anomalous behaviors: (a) an increasingly negative current in the deposition stage (labeled as “HER” effect) and (b) a minimum in the currents of the stripping stage plot (labeled as the “dip” effect). A practical strategy to apply AGNES avoiding the dip effect has been developed to quantify properly free Zn concentrations. The van den Berg–Ružic–Lee linearization method (assuming the existence of just 1:1 complexes) has been adapted to consider the dilution effect and the ionic strength changes. Aggregated stability constants and total ligand concentrations have been calculated from synthetic and wine titration data. The found complexing capacity in the studied wine (cT,L = 0.0179 ± 0.0007 M) indicates the contribution of ligands other than tartrate (which is confirmed to be the main one).

Milk, from medicine to food Mediterranean Europe: Catalonia, 19th-20th centuries

The spread of milk consumption was a significant change in the diet of Europeans, however it is one that has not been greatly studied with regard to the populations of Mediterranean Europe. In this article we shall analyse the ain circumstances that conditioned that process in Catalonia between the middle of the 19th century and 1936. In our study we shall argue that the consumption of milk in this area was only relevant in the 19th century in situations of illness or old age, and that it subsequently increased and acquired a new significance as a result of various factors. In particular, we shall emphasise: (a) the scientific advances in microbiology and nutrition, (b) the activities carried out by doctors and various public institutions to promote the consumption of fresh milk, and (c) the technological innovations in the milk producing sector. In Appendix 1 we show two maps representing the main territorial references that we shall mention.

Development of specific ITS markers for plant DNA identification within herbivorous insects

DNA based techniques have proved to be very useful methods to study trophic relationships 17 between pests and their natural enemies. However, most predators are best defined as omnivores, 18 and the identification of plant-specific DNA should also allow the identification of the plant 19 species the predators have been feeding on. In this study, a PCR approach based on the 20 development of specific primers was developed as a self-marking technique to detect plant DNA 21 within the gut of one heteropteran omnivorous predator (Macrolophus pygmaeus) and two 22 lepidopteran pest species (Helicoverpa armigera and Tuta absoluta). Specific tomato primers 23 were designed from the ITS 1-2 region, which allowed the amplification of a tomato DNA 24 fragment of 332 bp within the three insect species tested in all cases (100% of detection at t = 0) 25 and did not detect DNA of other plants nor of the starved insects. Plant DNA half-lives at 25ºC 26 ranged from 5.8h, to 27.7h and 28.7h within M. pygmaeus, H. armigera and T. absoluta, 27 respectively. Tomato DNA detection within field collected M. pygmaeus suggests dietary mixing 28 in this omnivorous predator and showed a higher detection of tomato DNA in females and 29 nymphs than males. This study provides a useful tool to detect and to identify plant food sources 30 of arthropods and to evaluate crop colonization from surrounding vegetation in conservation 31 biological control programs.

A linear optimization technique for graph pebbling

Graph pebbling is a network model for studying whether or not a given supply of discrete pebbles can satisfy a given demand via pebbling moves. A pebbling move across an edge of a graph takes two pebbles from one endpoint and places one pebble at the other endpoint; the other pebble is lost in transit as a toll. It has been shown that deciding whether a supply can meet a demand on a graph is NP-complete. The pebbling number of a graph is the smallest t such that every supply of t pebbles can satisfy every demand of one pebble. Deciding if the pebbling number is at most k is NP 2 -complete. In this paper we develop a tool, called theWeight Function Lemma, for computing upper bounds and sometimes exact values for pebbling numbers with the assistance of linear optimization. With this tool we are able to calculate the pebbling numbers of much larger graphs than in previous algorithms, and much more quickly as well. We also obtain results for many families of graphs, in many cases by hand, with much simpler and remarkably shorter proofs than given in previously existing arguments (certificates typically of size at most the number of vertices times the maximum degree), especially for highly symmetric graphs. Here we apply theWeight Function Lemma to several specific graphs, including the Petersen, Lemke, 4th weak Bruhat, Lemke squared, and two random graphs, as well as to a number of infinite families of graphs, such as trees, cycles, graph powers of cycles, cubes, and some generalized Petersen and Coxeter graphs. This partly answers a question of Pachter, et al., by computing the pebbling exponent of cycles to within an asymptotically small range. It is conceivable that this method yields an approximation algorithm for graph pebbling.

Building Capacity in Developing Countries : OER for Food Safety

The Food Safety Knowledge Network (FSKN) was developed through the collaboration of Michigan State University and a professional network of international food industry retailers and manufacturers. The key objective of the FSKN project is to provide technical resources, in a cost effective way, in order to promote food safety in developing countries and for small and less developed companies. FSKN uses a competency based model including a framework, OERs, and assessments. These tools are being used to support face-to-face training, fully online training, and to gauge the learning outcomes of a series of pilot groups which were held in India, Egypt, and China.

When the mummy is digital : preservation and dissemination

Most educational institutions include nowadays a digital repository as part of their development and positioning strategy. The main goals of a digital repository are preservation and dissemination, which are some how contradictory, especially if the repository follows an open approach, as it is designed, built and managed from an institutional perspective, although it is intended to be used by teachers and learners. This fact may lead to a low level of usage, as final users are not able to integrate the learning object repository into their learning process. In this paper we will discuss how to promote open educational resources by connecting open repositories with open social networks, bridging the gap between resources and final users (teachers and learners).

WePreserve 2009: DPE/Planets/CASPAR/nestor Joint Training Event: The Preservation challenge: basic concepts and practical applications (Barcelona, 23-27 març 2009)

Reseña del congreso WePreserve 2009 que tuvo lugar los pasados 23 al 27 de marzo en Barcelona, organizadopor la Facultad de Biblioteconomía y Documentación de la Universitat de Barcelona, con la colaboración del Institut d'Estudis Catalans, la Biblioteca de Catalunya y el Consorci de Biblioteques de Barcelona. El seminario 2009 WePreserve se celebra anualmente desde el año 2007 y participan todas las figuras de referencia europeas en materia de investigación en sistemas y metodologías que garantizan la preservación digital de los documentos: Digital Preservation Europe (DPE), Preservation and Long-term Access Through Networked Services (Planets), Cultural Artistic and Scientific Knowledge for Preservation, Access and Retrieval (CASPAR), y Network of expertise in Digital long-term preservation (nestor).

Implementation of a robust coded structured light technique for dynamic 3D measurements

This paper presents the implementation details of a coded structured light system for rapid shape acquisition of unknown surfaces. Such techniques are based on the projection of patterns onto a measuring surface and grabbing images of every projection with a camera. Analyzing the pattern deformations that appear in the images, 3D information of the surface can be calculated. The implemented technique projects a unique pattern so that it can be used to measure moving surfaces. The structure of the pattern is a grid where the color of the slits are selected using a De Bruijn sequence. Moreover, since both axis of the pattern are coded, the cross points of the grid have two codewords (which permits to reconstruct them very precisely), while pixels belonging to horizontal and vertical slits have also a codeword. Different sets of colors are used for horizontal and vertical slits, so the resulting pattern is invariant to rotation. Therefore, the alignment constraint between camera and projector considered by a lot of authors is not necessary

Natural abundance of stable isotopes (15N and 13C) and isotopic fractionation of sea bream muscle as markers of food and culture conditions and its relationship with metabolic and proteomic analyses

Els isòtops estables com a traçadors de la cadena alimentària, s'han utilitzat per caracteritzar la relació entre els consumidors i els seus aliments, ja que el fraccionament isotòpic implica una discriminació en contra de certs isòtops. Però les anàlisis d'isòtops estables (SIA), també es poden dur a terme en peixos cultivats amb dietes artificials, com la orada (Sparus aurata), la especie más cultivada en el Mediterráneo. Canvis en l'abundància natural d'isòtops estables (13C i 15N) en els teixits i les seves reserves poden reflectir els canvis en l'ús i reciclatge dels nutrients ja que els enzims catabòlics implicats en els processos de descarboxilació i desaminació mostren una preferència pels isòtops més lleugers. Per tant, aquestes anàlisis ens poden proporcionar informació útil sobre l'estat nutricional i metabòlic dels peixos. L'objectiu d'aquest projecte va ser determinar la capacitat dels isòtops estables per ser utilitzats com a marcadors potencials de la capacitat de creixement i condicions de cria de l'orada. En aquest sentit, les anàlisis d'isòtops estables s'han combinat amb altres metabòlics (activitats citocrom-c-oxidasa, COX, i citrat sintasa, CS) i els paràmetres de creixement (ARN/ADN). El conjunt de resultats obtinguts en els diferents estudis realitzats en aquest projecte demostra que el SIA, en combinació amb altres paràmetres metabòlics, pot servir com una eina eficaç per discriminar els peixos amb millor potencial de creixement, així com a marcador sensible de l'estat nutricional i d'engreix. D'altra banda, la combinació de l'anàlisi d'isòtops estables amb les eines emergents, com ara tècniques de proteòmica (2D-PAGE), ens proporciona nous coneixements sobre els canvis metabòlics que ocorren en els músculs dels peixos durant l‟increment del creixement muscular induït per l'exercici.

Efecto de los contenidos de C, Mn y Si en el comportamiento a fluencia en caliente de aceros de construcción al carbono y microaleados: aplicación a la obtención de grano ultrafino en productos largos laminados

Després d’aplicar alguns tractaments d’elaboració i conservació als aliments, queden bacteris lesionats. Aquests bacteris perden la capacitat de créixer en els medis de cultiu selectiu convencionals, de manera que se’n subestima el recompte. Malgrat això, poden recuperar-se als aliments i suposar un risc per la salut, ja que alguns encara poden mantenir activitat metabòlica i integritat estructural. En aquest projecte, es van optimitzar protocols de preparació de mostres per citometria de flux (CF) per avaluar l’estat fisiològic de patògens alimentaris (Escherichia coli O157:H7, Salmonella Enteritidis i Listeria monocytogenes) sotmesos a estrès. Es van estudiar principalment dos paràmetres fisiològics: la integritat de membrana, mitjançant iodur de propidi i fluorocroms de la família SYTO; i l’activitat respiratòria, per la reducció intracel•lular d’una sal de tetrazole, el CTC. En primer lloc, es van avaluar variables de protocol, com la concentració de colorant, la ràtio entre colorants, la solució de tinció i el temps d’incubació, en mostres control (cèl•lules sanes i mortes). A continuació, els protocols optimitzats es van aplicar a suspensions bacterianes en medi de cultiu que prèviament havien estat sotmeses a estressos físics i fisicoquímics. Durant l’etapa final del projecte, els coneixements adquirits sobre la preparació de mostres per CF es van aplicar a l’anàlisi de mostres de matriu complexa: amanides comercials inoculades amb E. coli O157:H7. Als assajos amb indicadors d’integritat de membrana en suspensions bacterianes sotmeses a estrès, es van poder quantificar cèl•lules amb la membrana parcialment danyada (presumptes cèl•lules lesionades). El recompte de cèl•lules que mantingueren l’activitat respiratòria després de ser sotmeses a estrès va ser superior al que es va obtenir mitjançant recompte en placa convencional, cosa que va evidenciar la presència de cèl•lules actives però no cultivables. La introducció d’estratègies per reduir les interferències provocades per les partícules alimentàries i l’ús d’un anticòs amb marcatge fluorescent va permetre detectar selectivament les cèl•lules d’E. coli O157:H7 i avaluar-ne la integritat de membrana simultàniament. L’anàlisi de cèl•lules bacterianes per CF requereix de la exhaustiva optimització dels protocols, que són específics per cada soca i matriu. Malgrat això, i a diferència del mètode convencional per recompte en placa, ofereix la possibilitat d’obtenir una gran quantitat d’informació sobre el sovint complex estat fisiològic d’una mostra.

Friction Stir Processing : a new microstructure improvement technique

In the present work, microstructure improvement using FSP (Friction Stir Processing) is studied. In the first part of the work, the microstructure improvement of as-cast A356 is demonstrated. Some tensile tests were applied to check the increase in ductility. However, the expected results couldn’t be achieved. In the second part, the microstructure improvement of a fusion weld in 1050 aluminium alloy is presented. Hardness tests were carried out to prove the mechanical propertyimprovements. In the third and last part, the microstructure improvement of 1050 aluminium alloy is achieved. A discussion of the mechanical property improvements induced by FSP is made. The influence of tool traverse speed on microstructure and mechanical properties is also discussed. Hardness tests and recrystallization theory enabled us to find out such influence