Evaluación de fibra dietética, isoflavonas y compuestos fenólicos con propiedades antioxidantes y antimicrobianas de quinoa (Chenopodium quinoa Willd.)

The consumption of quinoa (Chenopodium quinoa Willd.) has been steadily increasing due to its high nutritional value and health benefits associated with its high antioxidant capacity. The objective of this study was to determine the contents of dietary fiber, polyphenols, flavonoids and isoflavones, and how they contribute to the antioxidant and antimicrobial activity of six ecotypes of quinoa cultivated in three different zones of Chile. The ecotypes studied were: Ancovinto and Cancosa (Northern zone), Cáhuil and Faro (Central zone), and Regalona and Villarrica (Southern zone). The results indicate that all Chilean quinoa ecotypes could be considered as good sources of dietary fiber (12.23 g 100 g-1 dry matter) and polyphenols (161.32 mg Gallic Acid Equivalents (GAE) 100 g-1 dry matter). The North and Central ecotypes exhibited the highest isoflavone concentration. The Northern Cancosa was the ecotype that showed the highest flavonoid content (211.06 mg Catechin Equivalents (CAE) 100 g-1 dry matter). Based on the ORAC (Oxygen Radical Absorbance Capacity) assay, Ancovinto, Cancosa and Faro presented the highest antioxidant capacity (67.6 mmol Trolox Equivalents (TE) 100 g-1 dry matter). Regarding antimicrobial activity, Regalona ecotype showed the best performance against Saccharomyces cerevisiae and Listeria innocua. The bioactive compounds found in this study add new knowledge to the antioxidant and antimicrobial activity of Chilean quinoa seeds.El consumo de quinua (Chenopodium quinoa Willd.) está aumentando debido a su valor nutricional y beneficios para la salud relacionados con su capacidad antioxidante. El objetivo de presente estudio fue determinar los contenidos de fibra dietética, polifenoles, flavonoides e isoflavonas, y cómo estos compuestos contribuyen a la actividad antioxidante y antimicrobiana de seis ecotipos de quinua cultivados en tres zonas de Chile. Las muestras de quinua de la zona Norte se denominan Ancovinto y Cancosa, de la zona Centro se llaman Cáhuil y Faro, y de la zona Sur se denominan Regalona y Villarrica. Los resultados mostraron que todos los ecotipos de quinua chilena pueden considerarse buena fuente de fibra dietética (12,23 g 100 g-1 materia seca) y de polifenoles (161,32 mg de Equivalentes de Acido Gálico (EAG) 100 g-1 materia seca). Los ecotipos de la zona Norte y Centro mostraron la mayor concentración de isoflavonas. El ecotipo Cancosa, de la zona Norte, fue el que mostró el mayor contenido de flavonoides (211,06 mg Equivalentes de Catequina (ECA) 100 g-1 materia seca). Basado en el ensayo ORAC (del inglés Oxigen Radical Absorbance Capacity), los ecotipos Ancovinto, Cancosa y Faro, presentaron en promedio la mayor capacidad antioxidante (67,6 mmol de Equivalentes Trolox (ET) 100 g-1 materia seca). El ecotipo Regalona mostró la más alta actividad antimicrobiana frente a Saccharomyces cerevisiae y Listeria innocua. Los compuestos bioactivos encontrados en este estudio aportan nuevos conocimientos a la actividad antioxidante y antimicrobiana de las semillas de quinua chilena.Fil: Vega Gálvez, Antonio. Universidad de La Serena; ChileFil: Zura, Liliana. Universidad de La Serena; ChileFil: Lutz, Mariane. Universidad de Vlparaíso; ChileFil: Jagus, Rosa Juana. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Tecnologías y Ciencias de la Ingeniería "Hilario Fernández Long". Universidad de Buenos Aires. Facultad de Ingeniería. Instituto de Tecnologías y Ciencias de la Ingeniería "Hilario Fernández Long"; ArgentinaFil: Agüero, Maria Victoria. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Tecnologías y Ciencias de la Ingeniería "Hilario Fernández Long". Universidad de Buenos Aires. Facultad de Ingeniería. Instituto de Tecnologías y Ciencias de la Ingeniería "Hilario Fernández Long"; ArgentinaFil: Pastén, Alexis. Universidad de La Serena; ChileFil: Di Scala, Karina Cecilia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata; Argentina. Universidad Nacional de Mar del Plata. Facultad de Ingeniería; ArgentinaFil: Uribe, Elsa. Universidad de La Serena; Chil

Análisis geológico y numérico del flujo de lodo de la quebrada El Tejado del 31 de enero de 2022, Quito – Ecuador

El Distrito Metropolitano de Quito (DMQ), capital del Ecuador, está localizada en una cuenca a 2800 m.s.n.m. en el denominado Valle Interando. Se desarrolla en un contexto geológico marcado por la presencia de las laderas asociadas al complejo volcánico Pichincha al oeste y una serie de colinas, expresión de un sistema de fallas inversas al este. En el límite urbano occidental del DMQ existen cerca de 85 quebradas que se alimentan del agua de escorrentía del Complejo volcánico Pichincha, y a lo largo de la historia y desarrollo de la ciudad, han sido reemplazadas o modificadas por rellenos o alcantarillado (Fernández, 1990). La relación de la ciudad con las quebradas ha sido compleja debido a que son utilizadas como sitios para desalojo de basura, acumulación de escombros y la falta de políticas públicas o el incumplimiento de las mismas ha permitido un alto grado de exposición a fenómenos vinculados a la evolución y funcionamiento de dichos drenajes, como son movimientos en masa, hundimientos, flujos de lodo, inundaciones, entre otros. Desde el siglo XIX se ha documentado en la prensa escrita quiteña la afectación por flujos de lodo en sitios relacionados a drenajes intervenidos por el humano. Siendo uno de los más recordados el flujo de lodo o aluvión de La Gasca (sector residencial relacionado a la zona de estudio), del 25 de febrero de 1975, con un volumen aproximado de 52 000 m3, un espesor del depósito de 20 a 50 cm, que movilizó escombros, bloques de tamaño métricos, fragmentos de árboles y dejó como resultado dos muertos, destrucción parcial de varias viviendas, automóviles y la afectación a las vías del sector (Feininger, 1975). A finales de los años 90 y en la primera década del siglo XXI se realizaron intervenciones ingenieriles (obras estructurales de mitigación) a varios de los drenajes de las laderas del Pichincha, incluida la quebrada El Tejado, mediante la construcción de presas de embalse de cemento armado, presas de tierra, diques, rejillas para la retención de lodo, túneles de desvío de las aguas, canalización parcial de algunas quebradas, entre otras obras (Sierra, 2009). Desde el año 2019 la ciudad comenzó a enfrentar de nuevo la afectación directa por flujos de lodo generados en los drenajes intervenidos de las laderas del Pichincha, siendo el caso de mayor impacto por el número de víctimas mortales (más de 20) el ocurrido la tarde del 31 de enero de 2022, caso de estudio de la presente propuesta

Basil Seeds as a Novel Food, Source of Nutrients and Functional Ingredients with Beneficial Properties: A Review

Basil (Ocimum basilicum L.) is found worldwide and is used in the food, pharmaceutical, and cosmetic industries; however, the nutritional and functional properties of the seeds are scarcely known. Basil seeds contain high concentrations of proteins (11.4–22.5 g/100 g), with all the essential amino acids except S-containing types and tryptophan; dietary fiber (soluble and insoluble) ranging from 7.11 to 26.2 g/100 g lipids, with linoleic (12–85.6 g/100 g) and linolenic fatty acids (0.3–75 g/100 g) comprising the highest proportions; minerals, such as calcium, potassium, and magnesium, in high amounts; and phenolic compounds, such as orientine, vicentine, and rosmarinic acid. In addition, their consumption is associated with several health benefits, such as the prevention of type-2 diabetes, cardio-protection, antioxidant and antimicrobial effects, and anti-inflammatory, antiulcer, anticoagulant, and anti-depressant properties, among others. The focus of this systematic review was to study the current state of knowledge and explore the enormous potential of basil seeds as a functional food and source of functional ingredients to be incorporated into foods

Extraction Techniques for Bioactive Compounds and Antioxidant Capacity Determination of Chilean Papaya (Vasconcellea pubescens) Fruit

The aim of this work was to assess and compare different extraction methods by using high hydrostatic pressure (HHPE), ultrasound (UE), agitation (AE), and their combinations for the extraction of bioactive compounds of Chilean papaya. Extract antioxidant capacity was evaluated by three methods (i.e., DPPH, FRAP, and Voltammetry) and phenolic compounds and vitamin C were determined by HPLC. Papaya sample extraction was performed by HHPE at 500 MPa for 10 min and UE and AE for 30 min, respectively. The combined-extractions: HHPE-UE and HHPE-AE, were carried out for 5 min and 15 min, respectively. The highest values found were total phenolic 129.1 mg GAE/100 g FW, antioxidant capacity by DPPH 20.6 mM TE/100 g FW, and voltammetry 141.0 mM TE/100 g FW for HHPE-UE method in free compound extraction. Regarding vitamin C content, its highest value was found by HHPE-UE (74 mg/100 g FW) a combined extraction method. The phenolic compounds rutin and p-coumaric acid were found in all the extracts, both in free and bound forms, respectively. Besides, the combined techniques improved the extraction of bioactive compounds

Efects of infrared-assisted refractance window (TM) drying on the drying kinetics, microstructure, and color of physalis Fruit Purée

The objective of this work was to study the influence of the drying temperature, infrared (IR) radiation assistance, and the Mylar (TM) film thickness during Physalis fruit puree drying by the Refractance Window (TM) (RW (TM)) method. For this, a RW (TM) dryer layout with a regulated bath at working temperatures of 60, 75, and 90 degrees C, Mylar (TM) thicknesses of 0.19, 0.25, 0.30 mm and IR radiation of 250 W for assisting RW (TM) drying process was used. Experimental curves data were expressed in moisture ratio (MR) in order to obtain moisture effective diffusivities (non-assisted RW (TM): D-eff = 2.7-10.1 x 10(-10) m(2)/s and IR-assisted RW (TM): D-eff = 4.2-13.4 x 10(-10) m(2)/s) and further drying curves modeling (Page, Henderson-Pabis, Modified Henderson-Pabis, Two-Term, and Midilli-Kucuk models). The Midilli-Kucuk model obtained the best-fit quality on experimental curves regarding statistical tests applied (Coefficient of Determination (R-2), Chi-Square (chi(2)) and Root Mean Square Error (RMSE). Microscopical observations were carried out to study the RW (TM) drying conditions effect on microstructural changes of Physalis fruit puree. The main findings of this work indicated that the use of IR-assisted RW (TM) drying effectively accelerates the drying process, which achieved a decrease drying time around 60%. Thus, this combined RW (TM) process is strongly influenced by the working temperature and IR-power applied, and slightly by Mylar (TM) thickness.National Commission for Scientific and Technological Research-Chile (CONICYT) FONDECYT 117148

Effect of drying methods on drying kinetics, energy features, thermophysical and microstructural properties of Stevia rebaudiana leaves

BACKGROUND: Stevia leaves were subjected to convective hot-air, infrared and vacuum drying at 40, 60 and 80 °C, followed byan assessment of thermophysical properties and microstructure, along with drying kinetics modelling and evaluation of energyfeatures for all drying operations.RESULTS: Effective moisture diffusivity (Deff) showed dependency on temperature with values ranging from 1.08 × 10−12 to7.43 × 10−12 m2 s−1 for convective drying, from 0.71 × 10−12 to 6.60 × 10−12 m2 s−1 for infrared drying, and from1.29 × 10−12 to 5.39 × 10−12 m2 s−1 for vacuum drying. The thermal properties of the dried Stevia leaves under different dryingconditions showed values of density, specific heat, thermal diffusivity, thermal conductivity and thermal effusivity rangingfrom 95.6 to 116.2 kg m−3, 3050 to 3900 J kg−1 K−1, 4.28 × 10−7 to 5.60 × 10−7 m2 s−1, 0.16 to 0.23 W m−1 K−1 and 244 to305 W s0.5 m−2 K−1, respectively. As for microstructure, convective hot-air drying showed better preserved leaf characteristics,compared to infrared- and vacuum-drying, whereby scanning electron microscopy (SEM) image analysis also revealed noticeable differences at higher temperatures. Statistical analysis showed that the Midilli?Kuçuk model fitted best the experimentaldata of drying curves (0.961 < r2 < 0.999, 0.000064 < SSE < 0.005359, and 0.000074 < χ 2 < 0.006278). Comparison of thedrying methods with respect to energy features showed that convective drying at 80 °C led to lowest specific energy consumption (61.86 kW h kg−1) with highest efficiency (8.5%).CONCLUSION: The results of this study contribute to a better understanding of the drying behaviour and showed that thermophysical properties of dried Stevia leaves and energy features are affected by drying methods.Fil: Lemus Mondaca, Roberto. Universidad de Chile. Facultad de Ciencias Físicas y Matemáticas; ChileFil: Zura Bravo, Liliana. Universidad de Chile. Facultad de Ciencias Físicas y Matemáticas; ChileFil: Ah Hen, Kong. Universidad Austral de Chile; ChileFil: Di Scala, Karina Cecilia. Universidad Nacional de Mar del Plata. Facultad de Ingeniería. Departamento de Ingeniería Química. Grupo de Investigación en Ingeniería en Alimentos; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata; Argentin

Quality enhancement of chilled sardine (Sardina pilchardus) by employment of quinoa (Chenopodium quinoa Willd.) extract

Poster.-- WEFTA Seafood science for a change demand, held in Bilbao from the 9th to the 11th June 2014To extend the shelf life time during storage of fatty fish species, the employment of natural antioxidants represent a relevant choice. Recent efforts have focused on the positive role of antioxidant molecules present in different kinds of plant extracts. Quinoa (Chenopodium quinoa Willd.) is a native plant of the Andean region and has aroused great technological and commercial interest for both human and animal feeding because of the presence of high-protein content and a balanced amino acid presence. In the latest few years, this plant has attracted a great attention because of its antioxidant activity, playing an important role as functional and nutraceutical food. The present research was focussed on the quality loss of sardine (Sardina pilchardus) during its chill storage. Its basic objective was to investigate the effect of including an aqueous-ethanol extract of quinoa in the icing medium employed. For it, aqueous solutions of varying concentrations of quinoa extracts were individually tested as icing medium, being quality changes monitored for a 12-day chill storage of fish. A sensory quality enhancement was evident in sardine as a result of including increasing quinoa extract contents in the icing medium. Marked performances were obtained in sensory descriptors such as external odour and raw- and cooked-muscle odours; on the contrary, descriptors such as skin, consistency and muscle taste were hardly affected by the presence of plant extracts. Quinoa-treated fish were still acceptable at day 12, while control fish was found rejectable at this time. Concerning chemical assessments, an inhibitory effect of quinoa extracts on lipid damage development (free fatty acid and fluorescent compound assessments) and microbial activity (trimethylamine formation) was observed. However, the determination of peroxide value, thiobarbituric acid index, and total volatile base-nitrogen content did not imply a significant effect for the quinoa extract presence in the icing mediumN

Effect of temperature on rehydration kinetics, functional properties, texture and antioxidant activity of red pepper var. hungarian (capsicum annuum l.)

Dehydrated peppers at 60C were rehydrated at three temperatures (20, 40 and 60C) to analyze the effect of processing temperature on rehydration kinetics and quality attributes of final products. Several empirical and diffusive models were applied to simulate rehydration kinetics. Based on statistical results (sum of square error, root mean square error and chi-square), Weibull and exponential models obtained the best fit quality for the experimental data. Water holding capacity and rehydration ratio presented a maximum and minimum value at 40C, respectively, indicating structural modifications of pepper due to thermal processing. Based on the glass transition temperature of the dried samples, it could be inferred that peppers are susceptible to structural disruption during rehydration at the three working temperatures. Increasing rehydration temperatures lead to a reduction in the pepper firmness. The radical scavenging activity showed higher antioxidant activity at high temperatures (e.g., 60C) rather than at low temperatures (e.g., 20 and 40C).Fil: Zura Bravo, Liliana. Universidad de la Serena; ChileFil: Vega Gálvez, Antonio. Universidad de la Serena; ChileFil: Lemus Mondaca, Roberto. Universidad de la Serena; Chile. Universidad de Santiago de Chile; ChileFil: Ah-Hen, Kong Shun. Universidad Austral de Chile; ChileFil: Di Scala, Karina Cecilia. Universidad Nacional de Mar del Plata; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin

Rehydration Capacity of Chilean Papaya (Vasconcellea pubescens): Effect of Process Temperature on Kinetic Parameters and Functional Properties

Slabs of Chilean papaya hot air-dried at 60 °C were rehydrated at 20, 40, 60, and 80 °C to study the influence of process temperature on mass transfer kinetics during rehydration. Diffusive and empirical models were selected to simulate the experimental rehydration curves. All models parameters showed dependence with temperature, thus activation energy could be estimated according to an Arrhenius-type equation. Among the applied models, Weibull provided the best fit for each rehydration curve based on the statistical tests RMSE, SSE, and chi-square. According to these results, this model could be used to estimate the rehydration time of Chilean papaya. In addition, rehydration ratio and water-holding capacity were analyzed. Both indices showed a decrease with increasing rehydration temperature indicating modification of the papaya cell structure due to thermal treatment which resulted in a reduction of the rehydration ability, in particular at high rehydration temperatures.Fil: Zura, Liliana. Universidad de la Serena; ChileFil: Uribe, Elsa. Universidad de la Serena; ChileFil: Lemus Mondaca, Roberto. Universidad de la Serena; Chile. Universidad de Santiago de Chile; ChileFil: Saavedra Torrico, Jorge. Pontificia Universidad Catolica de Valparaiso; Chile. Centro Regional de Estudios en Alimentos Saludables; ChileFil: Vega Gálvez, Antonio. Universidad de la Serena; Chile. Universidad de la Serena; ChileFil: Di Scala, Karina Cecilia. Universidad Nacional de Mar del Plata. Facultad de Ingeniería; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin

Influence of air-drying temperature on drying kinetics, colour, firmness and biochemical characteristics of Atlantic salmon (Salmo salar L.) fillets

8 páginas, 2 tablas, 3 figurasIn this work the drying kinetics of Atlantic salmon (Salmo salar L.) fillets and the influence of air drying temperature on colour, firmness and biochemical characteristics were studied. Experiments were conducted at 40, 50 and 60 °C. Effective moisture diffusivity increased with temperature from 1.08 × 10−10 to 1.90 × 10−10 m2 s−1. The colour difference, determined as ΔE values (from 9.3 to 19.3), as well as firmness (from 25 to 75 N mm−1) of dried samples increased with dehydration temperature. The lightness value L∗ and yellowness value b∗ indicated formation of browning products at higher drying temperatures, while redness value a∗ showed dependence on astaxanthin value. Compared with fresh fish samples, palmitic acid and tocopherol content decreased in a 20% and 40%, respectively, with temperature. While eicosapentaenoic acid (EPA) content remained unchanged and docosahexaenoic acid (DHA) content changed slightly. Anisidine and thiobarbituric acid values indicated the formation of secondary lipid oxidation products, which is more relevant for longer drying time than for higher drying temperatures.Peer reviewe