45 research outputs found
Maximal isometric handgrip strength and endurance differences between elite and non-elite young judo athletes
Background and Study Aim: Judo is a combat sport in which the maintenance of handgrip strength is essential because the judokas repeat this action continuously during the struggle for grip. While descriptions of maximal isometric handgrip strength in judokas are relatively common, few data exist concerning the ability to resist successive isometric contractions in the hands and its relation to performance. The aim of this study was the differences and similarities between elite and non-elite young judokas in terms of maximal isometric handgrip strength and their endurance to this strength.Material and Methods: Seventy-three adolescents participants from three national (elite) and one regional team (non-elite) were tested. The maximal isometric handgrip strength was recorded during a maximum test of 6 s with an electronic Digimax dynamometer. The endurance to the isometric handgrip strength was measured by a test consisting of 8 contractions of 10 s each alternating with 10 s of passive rest, and was also recorded with the same machine.Results: The endurance test decreases the relative and mean isometric handgrip strength of male and female judokas (p≤0.01), irrespective of their competitive level. However, male and female elite judokas developed higher levels of relative isometric handgrip strength in the maximum test and during all contractions of the endurance test than non-elite judokas (p≤0.01 for both sexes). In all cases, the non-elite group took longer to reach the maximal isometric handgrip strength (p≤0.05).Conclusions: Maximal isometric handgrip strength and the endurance to this strength were able to distinguish between elite and non-elite young judokas. Coaches should include conditioning programs for both maximal isometric handgrip strength and the ability to resist successive isometric contractions to maximize performance
Evaluation of the Physical and Oxidative Stabilities of Fish Oil-in-Water-in-Olive Oil Double Emulsions (O1/W/O2) Stabilized with Whey Protein Hydrolysate
This work studied the physical and oxidative stabilities of fish oil-in-water-in-olive oil
double emulsions (O1/W/O2), where whey protein hydrolysate was used as a hydrophilic emulsifier.
A 20 wt.% fish oil-in-water emulsion, stabilized with whey protein hydrolysate (oil: protein ratio of
5:2 w/w) and with a zeta potential of ~�����40 mV, only slightly increased its D4,3 value during storage at
8 C for seven days (from 0.725 to 0.897 m), although it showed severe physical destabilization when
stored at 25 C for seven days (D4,3 value increased from 0.706 to 9.035 m). The oxidative stability
of the 20 wt.% fish oil-in-water emulsion decreased when the storage temperature increased (25 vs.
8 C) as indicated by peroxide and p-anisidine values, both in the presence or not of prooxidants
(Fe2+). Confocal microscopy images confirmed the formation of 20 wt.% fish oil-in-water-in-olive
oil (ratio 25:75 w/w) using Polyglycerol polyricinoleate (PGPR, 4 wt.%). Double emulsions were
fairly physically stable for 7 days (both at 25 and 8 C) (Turbiscan stability index, TSI < 4). Moreover,
double emulsions had low peroxide (<7 meq O2/kg oil) and p-anisidine (<7) values that did not
increase during storage independently of the storage temperature (8 or 25 C) and the presence or
not of prooxidants (Fe2+), which denotes oxidative stability.the I+D+i projects CTQ2017-87076-R and PID2020-114137RBI00
funded by MCIN/AEI/10.13039/50110001103
Optimization of the Emulsifying Properties of Food Protein Hydrolysates for the Production of Fish Oil-in-Water Emulsions
The incorporation of lipid ingredients into food matrices presents a main drawback—their
susceptibility to oxidation—which is associated with the loss of nutritional properties and the
generation of undesirable flavors and odors. Oil-in-water emulsions are able to stabilize and
protect lipid compounds from oxidation. Driven by consumers’ demand, the search for natural
emulsifiers, such as proteins, is gaining much interest in food industries. This paper evaluates
the in vitro emulsifying properties of protein hydrolysates from animal (whey protein concentrate)
and vegetal origin (a soy protein isolate). By means of statistical modelling and bi-objective
optimization, the experimental variables, namely, the protein source, enzyme (i.e., subtilisin, trypsin),
degree of hydrolysis (2–14%) and emulsion pH (2–8), were optimized to obtain their maximal
in vitro emulsifying properties. This procedure concluded that the emulsion prepared from the
soy protein hydrolysate (degree of hydrolysis (DH) 6.5%, trypsin) at pH 8 presented an optimal
combination of emulsifying properties (i.e., the emulsifying activity index and emulsifying stability
index). For validation purposes, a fish oil-in-water emulsion was prepared under optimal conditions,
evaluating its physical and oxidative stability for ten days of storage. This study confirmed that the
use of soy protein hydrolysate as an emulsifier stabilized the droplet size distribution and retarded
lipid oxidation within the storage period, compared to the use of a non-hydrolyzed soy protein isolate.Spanish Government
CTQ2017-87076-
Genotoxicity evaluation of graphene derivatives by a battery of in vitro assays
The interest of graphene materials has increased markedly in the recent years for their promising applications in many fields as food packing. These new applications have caused some concern regarding their safety for consumers since the intake of these materials may increase. In this sense, a battery of in vitro test is required before its use as a food contact material. Then, the aim of this study was to assess the potential mutagenicity and genotoxicity of graphene oxide (GO) and reduced-graphene oxide (rGO) following the recommendations of the European Food Safety Authority (EFSA). Thus, the mouse lymphoma assay (MLA) and the micronucleus test (MN) were performed in L5178YTk ± cells, and the Caco-2 cells were used for the standard and modified comet assays. The results indicated that GO (0–250 μg/mL) was not mutagenic in the MLA. However, rGO revealed mutagenic activity from 250 μg/mL and 125 μg/mL after 4h and 24h of exposure, respectively. In the MN test, negative results were obtained for both compounds at the concentrations assayed (0–250 μg/mL) for GO/rGO. Moreover, no DNA strand breaks, or oxidative DNA damage were detected in Caco-2 cells exposed to GO (0–250 μg/mL) and rGO (0–176.3 μg/mL for 24h and 0–166.5 μg/mL for 48h). Considering the mutagenic potential of rGO observed further investigation is needed to describe its toxic profile
Ciberseguridad : el reto del siglo XXI
El siglo XXI es el siglo del dato, su análisis y de la conectividad;
en definitiva, el siglo de la información en tiempo real y disponible
para cualquiera en cualquier lugar del mundo. Dichos datos están
impactando en todos los ámbitos de la sociedad y de la economía
de tal forma que no se entiende ningún sector productivo ni
ninguna relación social sin dato; todos tenemos algún lugar en las
redes sociales desde donde intercambiamos experiencias personales
o profesionales. Si a este hecho se le suma el auge de la
Inteligencia Artificial, se tiene un siglo en el que los avances tecnológicos
van a ser totalmente disruptivos para todos nosotros
Scientific Dissemination Conference: Contributions of Toxicology in Substance Safety Research and for Society
Las “Jornadas de divulgación científica: Aportaciones de la Toxicología en la investigación de la seguridad de las sustancias y para la sociedad” se celebraron el 19 de mayo de 2023 en la Facultad de Farmacia de la Universidad de Sevilla, gracias a una Ayuda recibida por el VII Plan Propio de la Universidad de Sevilla (VII PPIT-US) para actividades de divulgación científica. El objetivo fue divulgar entre nuestros alumnos los conocimientos científicos por parte de personal docente e investigador altamente cualificado, y también dar a conocer a la sociedad en general el trabajo de investigación científica de alto nivel que se está realizando en la US. La actividad iba dirigida a los alumnos de las asignaturas de “Toxicología”, “Quimioinformática, Investigación e Historia de la Farmacia”, “Laboratorio de Farmacia” (del Grado en Farmacia, Grado en Óptica y Optometría, y Doble Grado en Farmacia y Óptica y Optometría), y las asignaturas de “Toxicología de las Drogas de Abuso” o “Introducción a las Ciencias Forenses” (Grado en Criminología). Durante las Jornadas, que duraron 5,5 horas, se impartieron un total de 6 comunicaciones orales con diferente temática: el grafeno, las cianotoxinas, los aditivos aliáceos en alimentación humana y animal, los estilbenos en los vinos, o los bioplaguicidas; todas ellas sintetizadas en unos trípticos divulgativos repartidos entre los asistentes para su divulgación en su entorno social. Asimismo, se realizaron 2 ponencias invitadas por parte de expertos en Toxicología Forense y Ambiental, respectivamente. La actividad contó con casi un total de 75 asistentes y los resultados de las encuestas mostraron en general un alto grado de satisfacción con las mismas, mostrando las Jornadas como una enriquecedora actividad de divulgación científica, por la variedad de temas tratados, los nuevos conocimientos adquiridos y el acercamiento a la investigación e interés suscitado entre los asistentes.The " Scientific dissemination conference: Contributions of Toxicology in substance safety research and for society" were held on May 19th, 2023 at the Faculty of Pharmacy of the University of Seville, thanks to a financial support received by the VII Plan Propio of the University of Seville (VII PPIT-US) for scientific dissemination activities. The objective was to disseminate scientific knowledge among our students by highly qualified teaching and scientific personnel, and also to inform society in general of the high-level scientific research work that is being carried out in the University of Seville. The activity was aimed at students of the subjects of "Toxicology", "Chemoinformatics, Research and History of Pharmacy", " Laboratory of Pharmacy" (of the Degree in Pharmacy, Degree in Optics and Optometry, and Double Degree in Pharmacy and Optics and Optometry), and the subjects of "Toxicology of the Drugs of Abuse" or "Introduction to Forensic Sciences" (Degree in Criminology). During the Conference, which lasted 5.5 hours, 6 oral communications were given on graphene, cyanotoxins, alliaceous additives in human and animal feed, stilbenes in wines, or biopesticides. All of them were synthesized in informative triptychs distributed among the attendees for their dissemination in their social environment. Likewise, 2 invited presentations were given by experts in Forensic and Environmental Toxicology, respectively. The activity had 75 attendees and the results of the surveys generally showed a high degree of satisfaction with them, showing the Conference as an enriching outreach activity, due to the variety of topics covered, the new knowledge acquired and the approach to research and interest aroused among attendees
The Emotional and Attentional Impact of Exposure to One's Own Body in Bulimia Nervosa: A Physiological View
Background:
Body dissatisfaction is the most relevant body image disturbance in bulimia nervosa (BN). Research has shown that viewing one's own body evokes negative thoughts and emotions in individuals with BN. However, the psychophysiological mechanisms involved in this negative reaction have not yet been clearly established. Our aim was to examine the emotional and attentional processes that are activated when patients with BN view their own bodies.
Method:
We examined the effects of viewing a video of one's own body on the physiological (eye-blink startle, cardiac defense, and skin conductance) and subjective (pleasure, arousal, and control ratings) responses elicited by a burst of 110 dB white noise of 500 ms duration. The participants were 30 women with BN and 30 healthy control women. The experimental task consisted of two consecutive and counterbalanced presentations of the auditory stimulus preceded, alternatively, by a video of the participant's own body versus no such video.
Results:
The results showed that, when viewing their own bodies, women with BN experienced (a) greater inhibition of the startle reflex, (b) greater cardiac acceleration in the first component of the defense reaction, (c) greater skin conductance response, and (d) less subjective pleasure and control combined with greater arousal, compared with the control participants.
Conclusion:
Our findings suggest that, for women with BN, peripheral-physiological responses to self-images are dominated by attentional processes, which provoke an immobility reaction caused by a dysfunctional negative response to their own body.The present research was supported by grants from the Spanish Ministry of Economy and Competitiveness [PSI2009-08417 and PSI2012-31395]. P.P. was supported by grants from the Spanish Ministry of Science and Innovation and University Jaume I [ECO2011-23634, P1-1B2012-27, and JCI-2010-06790]
Optimization of the Emulsifying Properties of Food Protein Hydrolysates for the Production of Fish Oil-in-Water Emulsions
The incorporation of lipid ingredients into food matrices presents a main drawback—their susceptibility to oxidation—which is associated with the loss of nutritional properties and the generation of undesirable flavors and odors. Oil-in-water emulsions are able to stabilize and protect lipid compounds from oxidation. Driven by consumers’ demand, the search for natural emulsifiers, such as proteins, is gaining much interest in food industries. This paper evaluates the in vitro emulsifying properties of protein hydrolysates from animal (whey protein concentrate) and vegetal origin (a soy protein isolate). By means of statistical modelling and bi-objective optimization, the experimental variables, namely, the protein source, enzyme (i.e., subtilisin, trypsin), degree of hydrolysis (2–14%) and emulsion pH (2–8), were optimized to obtain their maximal in vitro emulsifying properties. This procedure concluded that the emulsion prepared from the soy protein hydrolysate (degree of hydrolysis (DH) 6.5%, trypsin) at pH 8 presented an optimal combination of emulsifying properties (i.e., the emulsifying activity index and emulsifying stability index). For validation purposes, a fish oil-in-water emulsion was prepared under optimal conditions, evaluating its physical and oxidative stability for ten days of storage. This study confirmed that the use of soy protein hydrolysate as an emulsifier stabilized the droplet size distribution and retarded lipid oxidation within the storage period, compared to the use of a non-hydrolyzed soy protein isolate
Diseño y estabilización de lípidos funcionales
El objetivo de esta tesis doctoral es desarrollar procesos de estabilización de ácidos
grasos Omega-3 mediante técnicas de emulsionado y microencapsulado, empleando
para ello agentes emulsificantes-antioxidantes de naturaleza peptídica, procedentes de la
hidrólisis enzimática de proteínas alimentarias tales como lactosuero, soja y bacaladilla.
Para ello, esta investigación cuenta con los siguientes objetivos específicos que dividen
este trabajo en tres secciones diferenciadas:
1. Obtención de hidrolizados de proteínas alimentarias con actividad emulsificante y
antioxidante.
2. Estudio de la estabilidad física y oxidativa de emulsiones de aceites ricos en ácidos
grasos Omega-3 estabilizadas con hidrolizados de proteínas alimentarias.
3. Microencapsulación de emulsiones de aceites ricos en ácidos grasos Omega-3
estabilizadas con hidrolizados de proteínas alimentarias mediante secado por
atomización.Tesis Univ. Granada