53 research outputs found
Análisis de los métodos ergonómicos aplicados en el área de la postcosecha de la industria florícola
En Ecuador un amplio número de industrias dedicadas al sector florícola, en las cuales se
han realizado estudios ergonómicos, presentan un alto índice de enfermedades de tipo
ocupacional. Esta investigación presenta un análisis bibliográfico con un enfoque
cuantitativo-cualitativo, con diseño no experimental, descriptivo, para determinar la relación
entre los resultados obtenidos de las evaluaciones ergonómicas aplicadas específicamente
en el área de postcosecha de la industria florícola. La investigación está direccionada al
área de postcosecha de la industria florícola, partiendo de la definición de los puestos más
comunes que conforman esta área. La aplicación del método estadístico ANOVA, se
determinó y detalló la relación existente entre los resultados de las investigaciones
utilizadas, la variación de los niveles de riesgo, las condiciones de los puestos y los
métodos ergonómicos más aplicados. El estudio muestra que en los tres métodos aplicados
existe un nivel de riesgo medio, requiriendo una mejora del puesto, supervisión médica,
capacitación y entrenamiento para el operario. Además de un rediseño de las áreas de
trabajo y ejecución de las tareas, que deben ser adaptables a las limitaciones físicas del
trabajador. El sector florícola debe asumir nuevas estrategias de ergonomía en el trabajo,
enfocándose en métodos establecidos para realizar las actividades y sub-actividades, en
condiciones óptimas para el trabajador, no solo para reducir, sino también para prevenir
factores de riesgo laboral, de manera que se brinde capacitación técnica, seguridad y
comodidad, a fin de dignificar el trabajo, aumentando paralelamente la productividad de la
empresa.In Ecuador, a large number of industries dedicated to the floriculture sector, in which
ergonomic studies have been carried out, present a high rate of occupational illnesses. This
research presents a bibliographic analysis with a quantitative-qualitative approach, with a
non-experimental, descriptive design, to determine the relationship between the results
obtained from the ergonomic evaluations applied specifically in the post-harvest area of the
flower industry. The research is focused on the post-harvest area of the flower industry,
starting from the definition of the most common positions that make up this area. The
application of the ANOVA statistical method determined and detailed the relationship
between the results of the research used, the variation in risk levels, the conditions of the
jobs and the most commonly applied ergonomic methods. The study shows that in the three
methods applied there is a medium level of risk, requiring an improvement of the position,
medical supervision, training and training for the operator. In addition to a redesign of the
work areas and execution of the tasks, which must be adaptable to the physical limitations of
the worker. The floriculture sector must assume new ergonomic strategies at work, focusing
on established methods to carry out activities and sub-activities, considering the physical
limitations of the worker, not only to reduce, but also to prevent occupational risk factors, in
order to provide technical training, safety and comfort, in order to dignify work, increasing the
company's productivity at the same time.0000-0001-9416-522
Impacto del uso de tecnologías no térmicas sobre distintos parámetros nutricionales y de calidad en alimentos líquidos / Non-thermal technologies impact on nutritional and quality parameters in liquid foods
In the last decade have appeared in the Spanish market new products based on mixtures of fruit juices and milk as well as beverages mixtures of fruit and/or vegetables, which have a good acceptance by consumers and with a high nutritional value largely due to its high content in bioactive compounds as well as antioxidant capacity.
Traditionally, liquid food such as fruit and/or vegetables juices, as well as milk, have been preserved by thermal treatment such as pasteurization and sterilization. However these processes can cause loss of compounds responsible for the organoleptic and nutritional quality of food.
Currently there is a growing demand by the consumer for minimally processed food and which in turn are safe from the microbiological point of view, a fact that is driving the development of new conservation methods. Nonthermal processes such as high hydrostatic pressure, pulsed electric fields and ultrasound, which can be used with this goal without affecting the quality of food. Although the effectiveness of these treatments is known for safe food, is now when is possible to produce the greater technological advances for it to marketing.
In the present doctoral thesis, the main objective is to establish the conditions of nonthermal processing to obtain beverages with a high content in bioactive compounds as well as antioxidant capacity. In addition it is important to compare the effects of these treatments on the organoleptic and nutritional characteristics, with those occurring after the implementation of a traditional heat treatment.
Subsequently, also it was studied the degree of permeability of the cell membranes of blueberries using the extent of the impedance, to optimize the parameters of processing and use thermal and nonthermal processing in the extraction of bioactive compounds with antioxidant capacity.En la última década han aparecido en el mercado español nuevos productos basados en mezclas de zumos de frutas y leche así como bebidas mezclas de vegetales, que presentan una buena aceptación por parte del consumidor y con un gran valor nutricional, debido en gran parte a su alto contenido en compuestos bioactivos así como capacidad antioxidante.
Tradicionalmente los alimentos líquidos como zumos de fruta y/o vegetales, así como la leche, han sido conservados mediante técnicas por calor como la esterilización. Sin embargo estos procesos pueden provocar una pérdida de compuestos responsables de la calidad organoléptica y nutricional de los alimentos.
Actualmente existe una demanda creciente por parte del consumidor de alimentos mínimamente procesados y que a la vez sean seguros desde el punto de vista microbiológico, hecho que está impulsando el desarrollo de nuevos métodos de conservación. Procesos no térmicos como las altas presiones hidrostáticas, pulsos eléctricos de alta intensidad y ultrasonidos, pueden utilizarse con este objetivo sin que se vea afectada la calidad de los alimentos. Aunque la eficacia de estos tratamientos se conoce para obtener alimentos seguros, es ahora cuando se están produciendo los mayores avances tecnológicos para hacer posible su comercialización.
En la presente tesis doctoral, el objetivo principal es establecer las condiciones de procesado no térmico para obtener bebidas con un alto contenido en compuestos bioactivos así como capacidad antioxidante.
Además se comparan los efectos de estos tratamientos sobre las características nutricionales y organolépticas con los que se producen tras la aplicación de un tratamiento térmico tradicional.
Posteriormente, se estudia el grado de permeabilidad de las membranas celulares de arándanos utilizando la medida de la
impedancia, para optimizar los parámetros del procesamiento y poder utilizar los tratamientos térmicos y no térmicos en la extracción de compuestos bioactivos con capacidad antioxidante
Optical Spectroscopy of X-Mega targets in the Carina Nebula - VI. FO 15: a new O-Type double-lined eclipsing binary
We report the discovery of a new O-type double-lined spectroscopic binary
with a short orbital period of 1.4 days. We find the primary component of this
binary, FO 15, to have an approximate spectral type O5.5Vz, i.e. a
Zero-Age-Main-Sequence star. The secondary appears to be of spectral type
O9.5V. We have performed a numerical model fit to the public ASAS photometry,
which shows that FO 15 is also an eclipsing binary. We find an orbital
inclination of ~ 80 deg. From a simultaneous light-curve and radial velocity
solution we find the masses and radii of the two components to be 30 +/- 1 and
16 +/- 1 solar masses and 7.5 +/- 0.5 and 5.3 +/- 0.5 solar radii. These radii,
and hence also the luminosities, are smaller than those of normal O-type stars,
but similar to recently born ZAMS O-type stars. The absolute magnitudes derived
from our analysis locate FO 15 at the same distance as Eta Carinae. From
Chandra and XMM X-ray images we also find that there are two close X-ray
sources, one coincident with FO 15 and another one without optical counterpart.
This latter seems to be a highly variable source, presumably due to a
pre-main-sequence stellar neighbour of FO 15.Comment: 11 pages, 9 figures, 3 tables. Accepted for publication in MNRAS.
Higher resolution version available at
http://lilen.fcaglp.unlp.edu.ar/papers2006.htm
Rosmarinus officinalis L. essential oils impact on the microbiological and oxidative stability of Sarshir (Kaymak)
This study investigated the effect of Rosmarinus officinalis L. essential oil, REO (one, two and three percent) on the microbiological and oxidative stability of Sarshir during 20 days of refrigerated storage (4 °C). Initially, the chemical composition (gas chromatography/mass spectrometry, GC/MS), antimicrobial (paper disc diffusion) and antioxidant (DPPH) properties of REO were evaluated. Then, the microbial safety, oxidative stability (peroxide and anisidine values) and overall acceptability of the product after addition of REO to Sarshir and the subsequent storage period were determined. According to GC/MS analysis, the major components of REO were α-pinene (24.6%), 1,8-cineole (14.1%), camphor (13.5%), camphene (8.1%) and limonene (6.1%), respectively. Moreover, it was also found that Limosilactobacillus fermentum (inhibition zone (IZ) of 23.5 mm) and Salmonella Typhi (IZ of 16.4 mm) were the most sensitive and resistant spoilage and pathogenic bacteria against REO, respectively. In addition, the half-maximal inhibitory concentration (IC50) of the REO was measured at 24.8 mg/mL, while the IC50 value of butylated hydroxytoluene (BHT) was 16.6 mg/mL. The highest and lowest bacterial populations were detected in the control and the sample containing 3% REO, respectively. The control had the highest extent of lipid oxidation, while the lowest peroxide and anisidine values were measured in Sarshir containing 3% REO
Alfabetización a través de las tecnologías de la información y comunicación (TIC) en el futuro del aprendizaje
The research process aims to discuss the role and impact that information and communication technology (ICT) presents in the future of the existing form of instruction and teaching. Highlights the importance of achieving computer skills and being literate in ICT. The study is aimed at topics related to computers and education that are introduced in pedagogy and training to promote ICT literacy among educators and students. In particular, it covers the current trends in the development of Information Technologies and the diversification originated in the way of learning and teaching, as well as the influences that this brings in the future of literacy. The document is made through a bibliographic review that analyzes various theoretical frameworks and methodologies designed to address the progress of ICT in order to incorporate this method in education in order to understand the empowerment that this issue has generated in the last times.El proceso investigativo tiene como objetivo discutir el papel y el impacto que la tecnología de la información y la comunicación (TIC) presenta en el futuro de la forma existente de instrucción y enseñanza. Resalta la importancia de alcanzar destrezas informáticas y estar alfabetizado en las TIC. El estudio está encaminado a temas relacionados con la informática y la educación que se introducen en la pedagogía y la formación para impulsar la alfabetización en TIC entre educadores y alumnos. En particular, cubre las tendencias actuales en el desarrollo de las Tecnologías de la Información y las diversificaciones originadas en la de manera de aprender y enseñar, así como también, las influencias que esto trae en el futuro de la alfabetización. El documento se realiza a través de una revisión bibliográfica donde se analizan diversos marcos teóricos y metodologías diseñadas para hacer frente al progreso de las TIC con el propósito de incorporar este método en la educación en aras de comprender el empoderamiento que este tema ha generado en los últimos tiempos
Electronic sensor technologies in monitoring quality of tea: A review
Tea, after water, is the most frequently consumed beverage in the world. The fermentation of tea leaves has a pivotal role in its quality and is usually monitored using the laboratory analytical instruments and olfactory perception of tea tasters. Developing electronic sensing platforms (ESPs), in terms of an electronic nose (e-nose), electronic tongue (e-tongue), and electronic eye (e-eye) equipped with progressive data processing algorithms, not only can accurately accelerate the consumer-based sensory quality assessment of tea, but also can define new standards for this bioactive product, to meet worldwide market demand. Using the complex data sets from electronic signals integrated with multivariate statistics can, thus, contribute to quality prediction and discrimination. The latest achievements and available solutions, to solve future problems and for easy and accurate real-time analysis of the sensory-chemical properties of tea and its products, are reviewed using bio-mimicking ESPs. These advanced sensing technologies, which measure the aroma, taste, and color profiles and input the data into mathematical classification algorithms, can discriminate different teas based on their price, geographical origins, harvest, fermentation, storage times, quality grades, and adulteration ratio. Although voltammetric and fluorescent sensor arrays are emerging for designing e-tongue systems, potentiometric electrodes are more often employed to monitor the taste profiles of tea. The use of a feature-level fusion strategy can significantly improve the efficiency and accuracy of prediction models, accompanied by the pattern recognition associations between the sensory properties and biochemical profiles of tea
Pulsed electric field (PEF) recovery of biomolecules from Chlorella : Extract efficiency, nutrient relative value, and algae morphology analysis
This study investigated the effects of pulsed electric field (PEF) (3 kV/cm, 44 pulses, 99 kJ/kg), solvent (H2O or 50 % DMSO) and time (0, 10, 20, 30, 60, 90, 120 and 180 min) on the extraction of Chlorella antioxidant biomolecules and minerals. The results showed that PEF treatment increased the biomolecules recovery. For the extraction time of 120 min, more proteins and polyphenols were obtained using water, while more chlorophyll a and b, and carotenoids were obtained using 50 % DMSO as the extraction solvent. The extracts mineral concentration (PEF vs control) were analysed including Mg, P, Ca, Fe and Zn, and the Relative Nutrient Values results indicated that Chlorella H2O-extracts could be used as a mineral source for different populations. Finally, the fluorescence and scanning electron microscopy revealed the electroporation effect of PEF
Enhancing nutrient recovery and bioactive compound extraction from spirulina through supercritical fluid extraction : implications for SH-SY5Y cell viability
This work explores the efficiency of supercritical fluid extraction (SFE) to recover minerals, pigments, and antioxidant compounds from the spirulina microalgae. Moreover, the fatty acids and phenolic profiles of the extracts obtained were also investigated, and the effect of the extracts on SH-SY5Y cell viability was tested. The extraction of phycocyanin was improved by SFE compared to conventional extraction, from 2.838 ± 0.081 mg/g dry matter (DM) (control) to 6.438 ± 0.411 mg/g DM (SFE). SFE treatment also improved chlorophyll a and carotenoid recoveries increasing from 5.612 ± 0.547 to 8.645 ± 0.857 mg/g DM and from 0.447 ± 0.096 to 0.651 ± 0.120 mg/g DM, respectively. Regarding minerals, the SFE improved Mg recovery with 77% more than the control extraction. Moreover, palmitoleic, stearic, γ-linolenic, eicosadienoic and eicosatrienoic acids recovery was improved by SFE. Phenolic profiles were identified via triple-TOF-LC-MS-MS. Considering heavy metals, a higher rate of Pb extraction was observed for the SFE extract, while no significant differences were observed for Hg between both extractions. Finally, SFE extract improved cell viability compared to the control extract. Thus, SFE constitutes an interesting tool to sustainably extract high-added-value compounds; however, potential contaminants such as Pb need to be controlled in the resulting extracts
Water-soluble polysaccharides from Opuntia stricta Haw. fruit peels: Recovery, identification and evaluation of their antioxidant activities
Opuntia stricta Haw. is considered as one of the most common cactus plant growing in Tunisia. Extracting valuable compounds from its fruit peel, considered as by-product, is drawing more and more attention, making it on the verge of commercialization. Water-soluble polysaccharides were extracted from Opuntia stricta Haw. peels, and their chemical composition assessed using thin layer chromatography. The antioxidant activities of the extracted polysaccharides were assessed using 2,2-diphenyl-1-picrylhydrazyl free radical scavenging activity, total antioxidant activity and reducing power capacity. The extraction yield of water-soluble polysaccharides was 7.53±0.86%. The chemical composition revealed the presence of rhamnose, arabinose, glucose, mannose, galactose and galacturonic acid. The infra-red spectroscopic analysis showed a similar structure to that of Opuntia ficus-indica polysaccharide peels. Additionally, the extracted polysaccharides exhibited high antioxidant activities. In fact, the free radical scavenging activity (half inhibition concentration = 6.5 mg ml-1 with 94.9% inhibition at 50 mg ml-1), the total antioxidant activity (100 μg ascorbic acid equivalent at 50 mg polysaccharides) and the reducing power capacity (absorbance 700 nm = 0.7 at 50 mg ml-1), appeared to be interesting compared to natural and synthetic antioxidants. Therefore, water-soluble polysaccharides from Opuntia stricta Haw. fruit peels could be a natural alternative to replace synthetic antioxidants
Evaluation of Pulsed Electric Field-Assisted Extraction on the Microstructure and Recovery of Nutrients and Bioactive Compounds from Mushroom (Agaricus bisporus)
Pulsed electric field (PEF) is a sustainable innovative technology that allows for the recovery of nutrients and bioactive compounds from vegetable matrices. A. bisporus was chosen for its nutritional value and the effect of PEF pretreatment was evaluated using different conditions of electric field (2-3 kV/cm), specific energy (50-200 kJ/kg) and extraction time (0-6 h) to obtain the best conditions for nutrient and bioactive compound extraction. Spectrophotometric methods were used to evaluate the different compounds, along with an analysis of mineral content by inductively coupled plasma mass spectrometry (ICP-MS) and the surface was evaluated using scanning electron microscopy (SEM). In addition, the results were compared with those obtained by conventional extraction (under constant shaking without PEF pretreatment). After evaluating the extractions, the best extraction conditions were 2.5 kV/cm, 50 kJ/kg and 6 h which showed that PEF extraction increased the recovery of total phenolic compounds in 96.86%, carbohydrates in 105.28%, proteins in 11.29%, and minerals such as P, Mg, Fe and Se. These results indicate that PEF pretreatment is a promising sustainable technology to improve the extraction of compounds and minerals from mushrooms showing microporation on the surface, positioning them as a source of compounds of great nutritional interest
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