75 research outputs found

    Reduction of colonic inflammation in HLA-B27 transgenic rats by feeding Marie Ménard apples, rich in polyphenols

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    Inflammatory bowel diseases (IBD) are immunomediated ailments affecting millions of individuals. Although diet is regarded as an important factor influencing IBD, there are no accepted dietary recommendations presently available. We administered 7.6 % lyophilised apples obtained from two cultivars (Golden Delicious and Marie Ménard, low and high in polyphenols, respectively) to HLA-B27 transgenic rats which develop spontaneous IBD. After 3 months feeding, rats fed Marie Ménard apples had reduced myeloperoxidase activity (3.6 (sem 0.3) v. 2.2 (sem 0.2) U/g tissue; P <0.05) and reduced cyclo-oxygenase-2 (P <0.05) and inducible NO synthase gene expression (P <0.01) in the colon mucosa and significantly less diarrhoea (P <0.05), compared with control rats. Cell proliferation in the colon mucosa was reduced significantly by feeding Golden Delicious apples, with a borderline effect of Marie Ménard apples. Gene expression profiling of the colon mucosa, analysed using the Whole Rat Genome 4 x 44 K Agilent Arrays, revealed a down-regulation of the pathways of PG synthesis, mitogen-activated protein kinase (MAPK) signalling and TNFalpha-NF-kappaB in Marie Ménard-fed rats. In the stools of the animals of this group we also measured a significant reduction of bacteria of the Bacteriodes fragilis group. In conclusion, the administration of Marie Ménard apples, rich in polyphenols and used at present only in the manufacturing of cider, ameliorates colon inflammation in transgenic rats developing spontaneous intestinal inflammation, suggesting the possible use of these and other apple varieties to control inflammation in IBD patient

    Kiwifruit waste valorisation through innovative snack development

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    Currently, in the case of kiwifruits, those fruit with a weight lower than 65 g are considered waste. The production of dried snacks with high nutritional functionality could be a valid alternative to use the kiwifruit waste, with positive economic impact on the entire production chain. Therefore, the aim of this work was to evaluate the effect of pulsed electric field – PEF (200 V cm-1) and/or osmotic dehydration – OD (trehalose at 40%) pre-drying treatments on drying kinetics at 50, 60, and 70°C, and on colour and nutritional properties (vitamin C and antioxidant compounds) of ‘Jintao’ (yellow-fleshed) kiwifruit snacks. At every temperature, the PEF treated snacks showed the highest drying rate. Moreover, PEF treatment appeared to be a valid innovative alternative for the production of fruit snacks with high nutritional quality. A better retention of vitamin C and antioxidant compounds was obtained in dried yellow kiwifruit subjected to PEF treatment

    Microencapsulación de compuestos bioactivos

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    En la presente investigación se estudió la microencapsulación de un extracto de antocianinas obtenido a partir de una extracción sólido-liquido de restos sólidos de piel de arándanos los cuales son un subproducto de la elaboración de jugo de arándanos. La encapsulación se realizó mediante liofilización utilizando como material de pared maltodextrina, almidón modificado y proteína de suero lácteo. Mediante un ensayo de mezcla se realizó una optimización de la eficiencia de encapsulación, la productividad de microcápsulas y la higroscopicidad del producto de manera tal de maximizar los dos primeros factores y minimizar el último en función del material encapsulante utilizado. Las propiedades de las microcápsulas se evaluaron tanto desde el punto de vista físico y químico como funcional. Los resultados indicaron que la mejor formulación para proteger las antocianinas es utilizar una mezcla 70:30 de proteína de suero lácteo y maltodextrina. Desde el punto de vista de la funcionalidad, el ensayo de digestión in vitro permitió determinar que según el tipo de material elegido para recubrir las microcápsulas, se puede dirigir la liberación de las antocianinas, ya sea hacia la fase de digestión estomacal o hacia la intestinal

    Estudio de emulsiones Pickering para la microencapsulación de aceites esenciales cítricos y su estabilización por liofilización

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    El proyecto consistió en estudiar las propiedades físicas de emulsiones Pickering preparadas a partir de almidón de arroz químicamente modificado y aceite esencial de mandarina verde. Para realizar este estudio primero se obtuvieron los materiales y se caracterizaron. Se utilizó almidón de arroz de dos variedades, YERUA y GURI, que fue químicamente modificado con anhídrido octenil succínico. Se caracterizó tanto el almidón nativo como el almidón modificado para evaluar las diferencias entre las variedades. Se determinó la estabilidad de las emulsiones preparadas con diferentes concentraciones de almidón (50, 100, 150, 200, 300, 400, 500, 600 mg/mL de aceite) para la misma relación de fases dispersa:continua (1:2). Las emulsiones que presentaron mejor estabilidad fueron las preparadas con el almidón modificado YERUA, desde 400 mg/mL. Luego del tratamiento térmico la emulsión de 600 mg/mL de esta misma variedad fue la única que se mantuvo estable durante el ciclo de congelación-descongelación, por lo que fue seleccionada para el ensayo de liofilización. A pesar de la estabilidad que presentó la emulsión, el porcentaje de recuperación de aceite fue muy bajo y pudo deberse a que la matriz encapsulante no encierra efectivamente al aceite esencial, el cual se volatiliza durante el proceso de liofilización

    Thermodynamics of SU(N) Yang-Mills theories in 2+1 dimensions II - The deconfined phase

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    We present a non-perturbative study of the equation of state in the deconfined phase of Yang-Mills theories in D=2+1 dimensions. We introduce a holographic model, based on the improved holographic QCD model, from which we derive a non-trivial relation between the order of the deconfinement phase transition and the behavior of the trace of the energy-momentum tensor as a function of the temperature T. We compare the theoretical predictions of this holographic model with a new set of high-precision numerical results from lattice simulations of SU(N) theories with N=2, 3, 4, 5 and 6 colors. The latter reveal that, similarly to the D=3+1 case, the bulk equilibrium thermodynamic quantities (pressure, trace of the energy-momentum tensor, energy density and entropy density) exhibit nearly perfect proportionality to the number of gluons, and can be successfully compared with the holographic predictions in a broad range of temperatures. Finally, we also show that, again similarly to the D=3+1 case, the trace of the energy-momentum tensor appears to be proportional to T^2 in a wide temperature range, starting from approximately 1.2 T_c, where T_c denotes the critical deconfinement temperature.Comment: 2+36 pages, 10 figures; v2: comments added, curves showing the holographic predictions included in the plots of the pressure and energy and entropy densities, typos corrected: version published in JHE

    Gene expression profile and genomic alterations in colonic tumours induced by 1,2-dimethylhydrazine (DMH) in rats

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    <p>Abstract</p> <p>Background</p> <p>Azoxymethane (AOM) or 1,2-dimethylhydrazine (DMH)-induced colon carcinogenesis in rats shares many phenotypical similarities with human sporadic colon cancer and is a reliable model for identifying chemopreventive agents. Genetic mutations relevant to human colon cancer have been described in this model, but comprehensive gene expression and genomic analysis have not been reported so far. Therefore, we applied genome-wide technologies to study variations in gene expression and genomic alterations in DMH-induced colon cancer in F344 rats.</p> <p>Methods</p> <p>For gene expression analysis, 9 tumours (TUM) and their paired normal mucosa (NM) were hybridized on 4 × 44K Whole rat arrays (Agilent) and selected genes were validated by semi-quantitative RT-PCR. Functional analysis on microarray data was performed by GenMAPP/MappFinder analysis. Array-comparative genomic hybridization (a-CGH) was performed on 10 paired TUM-NM samples hybridized on Rat genome arrays 2 × 105K (Agilent) and the results were analyzed by CGH Analytics (Agilent).</p> <p>Results</p> <p>Microarray gene expression analysis showed that <it>Defcr4</it>, <it>Igfbp5</it>, <it>Mmp7, Nos2, S100A8 </it>and <it>S100A9 </it>were among the most up-regulated genes in tumours (Fold Change (FC) compared with NM: 183, 48, 39, 38, 36 and 32, respectively), while <it>Slc26a3</it>, <it>Mptx</it>, <it>Retlna </it>and <it>Muc2 </it>were strongly down-regulated (FC: -500; -376, -167, -79, respectively). Functional analysis showed that pathways controlling cell cycle, protein synthesis, matrix metalloproteinases, TNFα/NFkB, and inflammatory responses were up-regulated in tumours, while Krebs cycle, the electron transport chain, and fatty acid beta oxidation were down-regulated. a-CGH analysis showed that four TUM out of ten had one or two chromosomal aberrations. Importantly, one sample showed a deletion on chromosome 18 including <it>Apc</it>.</p> <p>Conclusion</p> <p>The results showed complex gene expression alterations in adenocarcinomas encompassing many altered pathways. While a-CGH analysis showed a low degree of genomic imbalance, it is interesting to note that one of the alterations concerned <it>Apc</it>, a key gene in colorectal carcinogenesis. The fact that many of the molecular alterations described in this study are documented in human colon tumours confirms the relevance of DMH-induced cancers as a powerful tool for the study of colon carcinogenesis and chemoprevention.</p
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