A novel procedure to measure the antioxidant capacity of Yerba maté extracts

Yerba maté extracts have in vitro antioxidant capacity attributed to the presence of polyphenolic compounds, mainly chlorogenic acids and dicaffeoylquinic acid derivatives. DPPH is one of the most used assays to measure the antioxidant capacity of pure compounds and plant extracts. It is difficult to compare the results between studies because this assay is applied in too many different conditions by the different research groups. Thus, in order to assess the antioxidant capacity of yerba maté extracts, the following procedure is proposed: 100 µL of an aqueous dilution of the extracts is mixed in duplicate with 3.0 mL of a DPPH 'work solution in absolute methanol (100 µM.L-1), with an incubation time of 120 minutes in darkness at 37 ± 1 °C, and then absorbance is read at 517 nm against absolute methanol. The results should be expressed as ascorbic acid equivalents or Trolox equivalents in mass percentage (g% dm, dry matter) in order to facilitate comparisons. The AOC of the ethanolic extracts ranged between 12.8 and 23.1 g TE % dm and from 9.1 to 16.4 g AAE % dm. The AOC determined by the DPPH assay proposed in the present study can be related to the total polyphenolic content determined by the Folin-Ciocalteu assay

Sexuelle Belästigung, Gewalt und Gewaltschutz in Werkstätten für behinderte Menschen (WfbM) - Langfassung; Eine Untersuchung des Instituts für empirische Soziologie (IfeS) im Auftrag des Bundesministeriums für Familie, Senioren, Frauen und Jugend (BMFSFJ) und des Bundesministeriums für Arbeit und Soziales (BMAS)

Menschen mit Behinderungen sind einem hohen Risiko ausgesetzt, Gewalt in verschiedenen Lebensbereichen zu erfahren. Im Hinblick auf den Schutz vor Gewalt sind sie strukturell und rechtlich in einer besonders schwierigen Lage, vor allem wenn sie in Einrichtungen der Behindertenhilfe leben und arbeiten. Aus diesem Grund hat das Institut für empirische Soziologie (IfeS) im Auftrag des Bundesministeriums für Arbeit und Soziales (BMAS) und des Bundesministeriums für Familie, Senioren, Frauen und Jugend (BMFSFJ) eine Studie zu sexueller Belästigung und Gewalt in Werkstätten für behinderte Menschen (WfbM) durchgeführt. Der Abschlussbericht in Kurz- und Langfassung enthält die Ergebnisse der quantitativen und qualitativen Befragungen sowie Handlungsempfehlungen und Beispiele guter Praxis für einen verbesserten Gewaltschutz in WfbM

Gewalt und Gewaltschutz in Einrichtungen der Behindertenhilfe - Kurzfassung; Eine Untersuchung des Instituts für empirische Soziologie (IfeS) im Auftrag des Bundesministeriums für Familie, Senioren, Frauen und Jugend (BMFSFJ) und des Bundesministeriums für Arbeit und Soziales (BMAS)

Menschen mit Behinderungen sind einem hohen Risiko ausgesetzt, Gewalt in verschiedenen Lebensbereichen zu erfahren. Im Hinblick auf den Schutz vor Gewalt sind sie strukturell und rechtlich in einer besonders schwierigen Lage, vor allem wenn sie in Einrichtungen der Behindertenhilfe leben. Aus diesem Grund hat das Institut für empirische Soziologie (IfeS) im Auftrag des Bundesministeriums für Arbeit und Soziales (BMAS) und des Bundesministeriums für Familie, Senioren, Frauen und Jugend (BMFSFJ) eine Studie zu Gewalt gegen Menschen mit Behinderungen in Einrichtungen durchgeführt, die stationäre und ambulante Betreuungssettings umfasst. Der Abschlussbericht in Kurz- und Langfassung enthält die Ergebnisse der quantitativen und qualitativen Befragungen sowie Handlungsempfehlungen und Beispiele guter Praxis für einen verbesserten Gewaltschutz in Einrichtungen

School-based interventions modestly increase physical activity and cardiorespiratory fitness but are least effective for youth who need them most: an individual participant pooled analysis of 20 controlled trials

Objectives: To determine if subpopulations of students benefit equally from school-based physical activity interventions in terms of cardiorespiratory fitness and physical activity. To examine if physical activity intensity mediates improvements in cardiorespiratory fitness.Design: Pooled analysis of individual participant data from controlled trials that assessed the impact of school-based physical activity interventions on cardiorespiratory fitness and device-measured physical activity.Participants: Data for 6621 children and adolescents aged 4–18 years from 20 trials were included.Main outcome measures: Peak oxygen consumption (VO2Peak mL/kg/min) and minutes of moderate and vigorous physical activity.Results: Interventions modestly improved students’ cardiorespiratory fitness by 0.47 mL/kg/min (95% CI 0.33 to 0.61), but the effects were not distributed equally across subpopulations. Girls and older students benefited less than boys and younger students, respectively. Students with lower levels of initial fitness, and those with higher levels of baseline physical activity benefitted more than those who were initially fitter and less active, respectively. Interventions had a modest positive effect on physical activity with approximately one additional minute per day of both moderate and vigorous physical activity. Changes in vigorous, but not moderate intensity, physical activity explained a small amount (~5%) of the intervention effect on cardiorespiratory fitness.Conclusions: Future interventions should include targeted strategies to address the needs of girls and older students. Interventions may also be improved by promoting more vigorous intensity physical activity. Interventions could mitigate declining youth cardiorespiratory fitness, increase physical activity and promote cardiovascular health if they can be delivered equitably and their effects sustained at the population level

Production of dried yerba mate extracts with high polyphenol content and antioxidant capacity

El objetivo de la tesis fue obtener un producto en polvo para consumo con elevada capacidad antioxidante a partir de yerba mate. Para ello se abordaron una serie de objetivos particulares: seleccionar y adaptar técnicas de evaluación del contenido de polifenoles y de la capacidad antioxidante de los extractos; evaluar la influencia de la materia prima mediante la comparación de diferentes fracciones y procedencias geográficas; y optimizar la obtención de los extractos y su posterior secado. El contenido de polifenoles y la capacidad antioxidante se determinaron mediante los métodos de Folin-Ciocalteu y del radical DPPH, usando principalmente ácido clorogénico y Trolox como estándares. El uso de la fracción de hojas del material cosechado durante el inicio del periodo de cosecha permitió obtener extractos con alto contenido de polifenoles y alta capacidad antioxidante, ya que la fracción hojas posee mayor concentración de polifenoles totales que la fracción palos. En cuanto a las soluciones extractivas, tanto el agua como soluciones acuosas binarias de metanol y de etanol mostraron ser eficaces en la extracción de dichos compuestos fenólicos, lográndose extracciones cercanas al 55 % del valor máximo posible. La pérdida de polifenoles durante el secado spray usando maltodextrinas como agentes de secado fue despreciable, sugiriéndose que los compuestos que contribuyen al valor del contenido de polifenoles del producto en polvo son muy estables a las temperaturas ensayadas, o sus posibles productos de hidrólisis durante el proceso de secado mantienen su capacidad antioxidante. Los resultados confirman la potencialidad del mate soluble como un alimento funcional. Palabras Claves: yerba mate; antioxidantes; extracción; mate soluble; Illex paraguariensisThis thesis was aimed to obtain a powder for human consumption with high antioxidant capacity from yerba mate. Specific objectives included the selection and adaptation of techniques to measure phenol content and antioxidant capacity of the extracts; choosing the more adequate raw material by comparing different fractions and geographical origins; and finally optimizing the extraction and drying conditions. Total polyphenol content and antioxidant capacity were measured by Folin-Ciocalteu method and DPPH assay respectively, using mainly chlorogenic acid and Trolox as standards. The use of leaf fraction harvested during the early harvest was found to be the most convenient for obtaining yerba mate extracts rich in polyphenols with high antioxidant capacity, due to the higher polyphenol content of this fraction compared with the stick one. Water and aqueous binary solutions of methanol and ethanol were found to be suitable for extraction of total polyphenols, reaching around 55% of the maximum value possible to achieve. Loss of polyphenolic compounds during spray-drying was negligible, suggesting that polyphenols compounds present in maté extracts were stable during spray drying or their hydrolysis products were still reactive to the Folin–Ciocalteu reagent. These results confirmed the potentiality of the soluble mate as a functional food. Keywords: yerba mate; antioxidants; extraction, soluble mate; IllexparaguariensisFil:Hartwig, Vanessa Graciela. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina

Optimization of the Extraction of Antioxidants and Caffeine from Maté (Ilex paraguariensis) Leaves by Response Surface Methodology

Optimal conditions for the industrial extraction of total polyphenols from maté (Ilex paraguariensis) were determined using response surface methodology, with two independent variables: ethanol percentage of the extraction solution and liquid to solid ratio. Response variables were total polyphenol content, antioxidant capacity, concentration of total polyphenols and caffeine content. The optimal conditions found were a liquid to solid ratio from 8 - 9 w w-1 and ethanol percentage of the extraction solution from 30 -50 % w w-1. Under these conditions the main predicted values corresponding to leaf extracts were 40 μg chlorogenic acid equivalents mL-1 of original extract, 13 g chlorogenic acid equivalents per 100 g dry matter for total polyphenol content, 22 g Trolox equivalents and 15.5 g ascorbic acid equivalents per 100 g dry matter for antioxidant capacity. The total polyphenol content of twig extracts was 36% lower than that in the leaf extracts