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Localización de equipos Bess mediante algoritmos genéticos considerando criterios de estabilidad de voltaje
(Universidad de Chile, 2017)
investigación respecto de estos servicios para evaluar la relevancia de incorporar los equipos BESS en los sistemas eléctricos. En efecto, estos estudios han permitido demostrar que la flexibilidad que proveen estos medios de almacenamiento no solo es...
Evaluación de distintas técnicas de conservación en peras "Packham's Triumph" mínimamente procesadas
(Universidad de Chile, 2012)
Las operaciones unitarias involucradas en la obtención de frutas mínimamente procesadas en fresco (MPF) limitan su vida útil, debido a un aumento en la tasa respiratoria, respuesta y producción de etileno, y pardeamiento enzimático. En el presente...
New eating habits and current lifestyle with little time to prepare balanced meals, have caused a demand for natural, fresh, healthy and ready to consume products as minimally processed fruits (MPF), also known as fresh-cut fruits, becoming fresh-cut pears an interesting alternative. The unit operations involved in obtaining these products limit their life, due to an increase in respiratory rate, ethylene synthesis and response, and as well as initiate enzymatic browning reactions by the contact of enzymes with substrates located in different parts prior cutting. In the present study, fresh-cut pears dipping in: citric acid (CA) (2 g·L-1), ascorbic acid (AA) (2 g·L-1), L-cysteine (C) (2 g·L-1) and ethylenediaminetetraacetic acid (EDTA) (1 g·L-1) was evaluated, during 8 days at 5 °C. The treatments used were: control on water; CA + AA + C; CA + C + EDTA; AA + C + EDTA; CA + AA + EDTA; CA + AA + C + EDTA. Respiratory rate, firmness, chemical and color parameters, sensory quality and polyphenol oxidase activity (PPO) were evaluated. A completely randomized design was used, with six treatments and variance analyses with a 5 % of significance were used. After processing (1-4 h) all slices had higher respiration rates (23,2 to 36,2 mg CO2·kg-1·h-1) compared with the whole fruit (6,9 mg CO2·kg-1·h-1). After 6 days, there were not significant differences between treatments (6,7 to 10 mg CO2·kg-1·h-1). On day 1, slices control and CA + AA + EDTA (without C) presented lightness (L) values of 73,4 and 74 respectively. Slices with C presented higher values from 77,3 to 78,3. Then on day 8 slices control and CA + AA + EDTA, showed values of 73,8 and 70,8 respectively and slices with C had the highest values from 74,1 to 75,6. Similar behavior was observed in the PPO activity. Slices with C had the lowest activity with values ranging from 1,3 to 2,7 U·mg-1·prot-1, contrary to slices with C slices without C presented 3,4 to 3,9 U·mg-1·prot-1 values. On the visual aspect slices with AC + C + EDTA and AC + AA + C + EDTA were the better evaluated. Antibrowning agents did not influence the chemical and firmness parameters. And it was concluded that treatment with C, were most effective in reducing enzymatic browning....
New eating habits and current lifestyle with little time to prepare balanced meals, have caused a demand for natural, fresh, healthy and ready to consume products as minimally processed fruits (MPF), also known as fresh-cut fruits, becoming fresh-cut pears an interesting alternative. The unit operations involved in obtaining these products limit their life, due to an increase in respiratory rate, ethylene synthesis and response, and as well as initiate enzymatic browning reactions by the contact of enzymes with substrates located in different parts prior cutting. In the present study, fresh-cut pears dipping in: citric acid (CA) (2 g·L-1), ascorbic acid (AA) (2 g·L-1), L-cysteine (C) (2 g·L-1) and ethylenediaminetetraacetic acid (EDTA) (1 g·L-1) was evaluated, during 8 days at 5 °C. The treatments used were: control on water; CA + AA + C; CA + C + EDTA; AA + C + EDTA; CA + AA + EDTA; CA + AA + C + EDTA. Respiratory rate, firmness, chemical and color parameters, sensory quality and polyphenol oxidase activity (PPO) were evaluated. A completely randomized design was used, with six treatments and variance analyses with a 5 % of significance were used. After processing (1-4 h) all slices had higher respiration rates (23,2 to 36,2 mg CO2·kg-1·h-1) compared with the whole fruit (6,9 mg CO2·kg-1·h-1). After 6 days, there were not significant differences between treatments (6,7 to 10 mg CO2·kg-1·h-1). On day 1, slices control and CA + AA + EDTA (without C) presented lightness (L) values of 73,4 and 74 respectively. Slices with C presented higher values from 77,3 to 78,3. Then on day 8 slices control and CA + AA + EDTA, showed values of 73,8 and 70,8 respectively and slices with C had the highest values from 74,1 to 75,6. Similar behavior was observed in the PPO activity. Slices with C had the lowest activity with values ranging from 1,3 to 2,7 U·mg-1·prot-1, contrary to slices with C slices without C presented 3,4 to 3,9 U·mg-1·prot-1 values. On the visual aspect slices with AC + C + EDTA and AC + AA + C + EDTA were the better evaluated. Antibrowning agents did not influence the chemical and firmness parameters. And it was concluded that treatment with C, were most effective in reducing enzymatic browning....
Expansión generación-transmisión a largo plazo en Latinoamérica: horizonte 2040 con escenarios de energía solar en Chile y descarbonización
(Universidad de Chile, 2021)
El potencial en recursos energéticos renovables que tiene Latinoamérica y la diversidad territorial de la región motiva a explorar la complementariedad y aporte de dichos recursos. Esto se puede lograr mediante la interconexión entre los países que...
Acerca del poblamiento inicial de Rapa Nui. Una mirada desde los almidones adheridos a artefactos Líticos
(Universidad de Chile, 2014)
que contrasta
con la importante cantidad de datos que han sido generados sobre este tema para
el resto del Pacífico. Cabe señalar que, por un lado, nuestra comprensión de los
momentos tempranos de Rapa Nui ha sido fuertemente opacada por el...
procesos internos propios de la isla, en cambio, han sido abordados predominantemente desde temáticas como la arquitectura monumental, los patrones de asentamiento o el colapso ecológico y cultural, que han dado luces sobre momentos más tardíos de la...
procesos internos propios de la isla, en cambio, han sido abordados predominantemente desde temáticas como la arquitectura monumental, los patrones de asentamiento o el colapso ecológico y cultural, que han dado luces sobre momentos más tardíos de la...
Geocronología U/Pb en circones de la ignimbrita Pudahuel
(Universidad de Chile, 2015)
La Ignimbrita Pudahuel corresponde a un depósito asociado al Complejo Volcánico Maipo perteneciente la Zona Volcánica Sur de la Cordillera de los Andes, en la zona central de Chile. Su génesis es asociada a la formación de la Caldera Diamante y se...
Influencia de la latitud, variedad y estado de maduración en la evolución de los compuestos responsables del flavor (fenoles y volátiles) en aceite de oliva virgen extra
(Universidad de Chile, 2017)
En esta investigación se estudió la influencia del estado de maduración, variedad y zona de cultivo sobre la concentración de los compuestos fenólicos y volátiles de los AOVEs de las variedades Arbequina, Koroneiki y Arbosana, provenientes de dos...
In this research the influence of the ripening stage, variety and growing region on the concentration of phenolic and volatile compounds in EVOOs from Arbequina, Koroneiki and Arbosana varieties from two geographical areas of Chile: IV Region of Coquimbo (Limarí Valley) and VII Region of Maule (Molina) were studied. A characterization of the physicochemical quality of the oils was performed (free acidity, peroxide value, K232, K270, ΔK absorption and color) and fatty acid composition; all the samples were classified as EVOO according to the standards given by International Olive Oil Council. The determination of phenolic compounds through solid phase extraction (SPE) followed by high-performance liquid chromatography (HPLC) analysis led as result significant differences between varieties, the highest concentration was found in the Koroneiki variety, followed by ‘Arbosana’ and lastly ‘Arbequina’. The concentration of phenolic compounds was also affected by the ripening stage of the olive, with a tendency to decrease as the ripening level of the olive progresses, and by the geographical origin, finding oils with the highest phenolic content in the Limarí Valley in comparison to the Molina zone. The main phenolic compounds found in the three varieties corresponded to derivatives of oleuropein and ligstroside. The measurement of volatile compounds through soli-phase microextraction (SPME) followed by gas chromatography (GC), displayed that the main compounds found in the oils were Hexanal, E-2-hexenal and Hexanol. In general, the largest concentration of these three compounds was found in the oils from the Molina zone. In the Limarí Valley a defined tendency in which the Arbequina variety displayed a larger concentration of volatile compounds followed by ‘Arbosana’ and ‘Koroneiki’ was shown. On the other hand, the influence of the ripening stage was observed, in which the concentration of prevalent volatile compounds increased to the ripening stage E4 or E5 to subsequently to decrease or stay in the E6 and E7 stage...
In this research the influence of the ripening stage, variety and growing region on the concentration of phenolic and volatile compounds in EVOOs from Arbequina, Koroneiki and Arbosana varieties from two geographical areas of Chile: IV Region of Coquimbo (Limarí Valley) and VII Region of Maule (Molina) were studied. A characterization of the physicochemical quality of the oils was performed (free acidity, peroxide value, K232, K270, ΔK absorption and color) and fatty acid composition; all the samples were classified as EVOO according to the standards given by International Olive Oil Council. The determination of phenolic compounds through solid phase extraction (SPE) followed by high-performance liquid chromatography (HPLC) analysis led as result significant differences between varieties, the highest concentration was found in the Koroneiki variety, followed by ‘Arbosana’ and lastly ‘Arbequina’. The concentration of phenolic compounds was also affected by the ripening stage of the olive, with a tendency to decrease as the ripening level of the olive progresses, and by the geographical origin, finding oils with the highest phenolic content in the Limarí Valley in comparison to the Molina zone. The main phenolic compounds found in the three varieties corresponded to derivatives of oleuropein and ligstroside. The measurement of volatile compounds through soli-phase microextraction (SPME) followed by gas chromatography (GC), displayed that the main compounds found in the oils were Hexanal, E-2-hexenal and Hexanol. In general, the largest concentration of these three compounds was found in the oils from the Molina zone. In the Limarí Valley a defined tendency in which the Arbequina variety displayed a larger concentration of volatile compounds followed by ‘Arbosana’ and ‘Koroneiki’ was shown. On the other hand, the influence of the ripening stage was observed, in which the concentration of prevalent volatile compounds increased to the ripening stage E4 or E5 to subsequently to decrease or stay in the E6 and E7 stage...
Aproximaciones a la composición y al potenciamiento de elementos de la Identidad Boliviana
(Universidad de Chile, 2018)
entre los aymaras.
9
1.2.1 Problema sociocultural en Bolivia
Para comenzar a dialogar con la realidad sociocultural en bolivia, primero resulta
primordial indagar sobre los alcances de la construcción de una identidad nacional. Sobre...
, producto de la migración del campo a la ciudad y la pluriculturalidad de Bolivia. Álvaro García Linera en una entrevista sobre su libro Nación, Mestizaje y Plurinacionalidad publicado en el 12 año 2014, le preguntan: ¿Qué es...
, producto de la migración del campo a la ciudad y la pluriculturalidad de Bolivia. Álvaro García Linera en una entrevista sobre su libro Nación, Mestizaje y Plurinacionalidad publicado en el 12 año 2014, le preguntan: ¿Qué es...
Estrategias de despacho de una planta de concentración solar térmica con almacenamiento
(Universidad de Chile, 2017)
Chile tiene un enorme potencial de energías renovables, en particular en recursos solares en la zona norte de su país. En el mundo el costo de estas tecnologías ha disminuido considerablemente volviéndolas competitivas en el mercado. Sin embargo, su...
Relaciones de fases y distribución de plomo durante el tratamiento de mata de cobre compleja rica en impurezas mediante carburación
(Universidad de Chile, 2015)
La presente tesis fue desarrollada en el marco del proyecto FONDECYT Regular 1120341 denominado Relaciones de fase y distribución de arsénico, antimonio y plomo durante el tratamiento de materiales complejos de cobre ricos en impurezas mediante el...
Generación de energía hidroeléctrica en canales de regadío
(Universidad de Chile, 2012)
La escasa disponibilidad del agua es un tema de primera importancia a nivel nacional y mundial, es por este motivo que se evalúa el desarrollo de un proyecto de micro central de pasada de generación hidroeléctrica en el Fundo Santa Isidora de...