Person: Rosales Conrado, Noelia
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First Name
Noelia
Last Name
Rosales Conrado
Affiliation
Universidad Complutense de Madrid
Faculty / Institute
Ciencias Químicas
Department
Química Analítica
Area
Química Analítica
Identifiers
7 results
Search Results
Now showing 1 - 7 of 7
Item Determination of phenolic compounds in residual brewing yeast using matrix solid-phase dispersion extraction assisted by titanium dioxide nanoparticles(Journal of Chromatography A, 2019) Gómez Mejía, Esther; Rosales Conrado, Noelia; León González, María Eugenia De; Madrid Albarrán, María Yolanda; ELSEVIERA simple and efficient low-cost matrix solid-phase dispersion (MSPD) extraction based on TiO2nanopar-ticles (NPs) and diatomaceous earth has been developed for the recovery of phenolic compounds fromresidual brewing yeast. Experimental conditions for MSPD extraction were optimized by an experimen-tal design approach. A screening factorial design plus replicates at the center point, followed by surfaceresponse analysis were used. The simultaneous identification and quantification of eleven main nat-ural polyphenols: caffeic, chlorogenic, p-coumaric, 3,4-dihydroxibenzoic, trans-ferulic and gallic acids,kaempferol, myricetin, naringin, quercetin and rutin, was possible by combining MSPD and capillaryliquid chromatography couple to a diode array detection system (cLC-DAD) and liquid chromatogra-phy couple to a triple quadrupole analyzer (LC–MS/MS). Moreover, residual brewing yeast extracts wereevaluated in terms of DPPH (1,1-diphenyl–2 picrylhydrazyl) free radical scavenging activity. Polyphenol-nanoparticle interaction was studied by UV–vis spectroscopy and electron transmission microscopy(TEM), pointing out a stable interplay that assists phenolic isolation. The extracted polyphenol quan-tities were within the 3.2-1,500 g g−1range, and the high antioxidant activity estimated suggested thatdeveloped MSPD is a successful, simple, efficient and rapid method for the extraction and recovery of bioactive phenolic compounds, which promotes the reuse and re-evaluation of brewing yeast agri-foodby-products.Item Extraction of polyphenols and synthesis of new activated carbon from spent coffee grounds(Scientific Reports, 2019) Ramón-Gonçalves, Marina; Alcaraz, Lorena; Pérez-Ferreras, Susana; León González, María Eugenia De; Rosales Conrado, Noelia; López, Félix A.; Nature ResearchA valorization process of spent coffee grounds (SCG) was studied. Thus, a two-stage process, the first stage of polyphenols extraction and synthesis of a carbonaceous precursor and a subsequent stage of obtaining activated carbon (AC) by means of a carbonization process from the precursor of the previous stage, was performed. The extraction was carried out with a hydro-alcoholic solution in a pressure reactor, modifying time, temperature and different mixtures EtOH:H2O. To optimize the polyphenols extraction, a two-level factorial experimental design with three replicates at the central point was used. The best results were obtained by using a temperature of 80 °C during 30 min with a mixture of EtOH:H2O 50:50 (v/v). Caffeine and chlorogenic acid were the most abundant compounds in the analysed extracts, ranging from 0.09 to 4.8 mg∙g−1 and 0.06 to 9.7 mg∙g−1, respectively. Similarly, an experimental design was realized in order to analyze the influence of different variables in the AC obtained process (reaction time, temperature and KOH:precursor ratio). The best results were 1 h, 850 °C, and a mixture of 2.5:1. The obtained activated carbons exhibit a great specific surface (between 1600 m2∙g−1 and 2330 m2∙g−1) with a microporous surface. Finally, the adsorption capacity of the activated carbons was evaluated by methylene blue adsorption.- Project number: 47
Item Integración de los enfoques AICLE y CTIM en las actividades experimentales del grupo bilingüe de la Facultad de Educación(2019) Peña Martínez, Juan; Rosales Conrado, Noelia; Sánchez Gómez, Pedro; García Núñez, Iván; Herrero Ojalvo, Ignacio GilbertoEn el presente proyecto se han rediseñado las prácticas de Física del grupo bilingüe para que los estudiantes apliquen el doble enfoque Ciencia-Tecnología-Ingeniería-Matemáticas (CTIM) y Aprendizaje Integrado de Ciencias en Lengua Extranjera (AICLE). Asimismo, se ha recabado su valoración para futuros trabajos. Item Residual brewing yeast as a source of polyphenols: Extraction, identification and quantification by chromatographic and chemometric tools(Food Chemistry, 2018) León González, María Eugenia De; Gómez Mejía, Esther; Rosales Conrado, Noelia; Madrid Albarrán, María YolandaA method combining aqueous extraction, reversed-phase high-performance capillary liquid chromatography with photodiode array detection (cLC-DAD) and chemometric tools, was developed to determine phenolic compounds in residual brewing yeast. The effect of temperature, nature of extraction solvent and method for separation of extract solution were studied to optimize the extraction conditions on the basis of total phenolic content (TPC), total flavonoids content (TFC) and antioxidant capacity. Polyphenols were determined by cLC-DAD. Flavonols as rutin and kaempferol, flavonoids as naringin, phenolic acids as gallic acid and antioxidants as trans-ferulic and p-coumaric acids were found and quantified in the brewing residue. Data were subjected to evaluation using multifactor ANOVA and principal component analysis (PCA), both showing that lyophilization pretreatment affects the content of individual polyphenols and that residual brewing yeast contains higher polyphenol amounts than the liquid beer waste. The obtained results suggest that residual brewing yeast could be a source of polyphenols.Item Extraction, identification and quantification of polyphenols from spent coffee grounds by chromatographic methods and chemometric analyses(WASTE MANAGEMENT, 2019) Ramón-Gonçalves, Marina; Gómez Mejía, Esther; Rosales Conrado, Noelia; León González, María Eugenia De; Madrid, YolandaA solid-liquid extraction method using ethanol-water mixtures was combined with cLC-DAD, LC-MS/MS and chemometric analyses for establishing the optimum extraction conditions of valuable polyphenols from spent coffee grounds. Chlorogenic and p-coumaric acids were the most abundant polyphenols found, ranging from 0.02 to 4.8 mg g−1 and 0.173–0.50 mg g−1, respectively. In addition, total polyphenol content (9–29 mg GAE g−1 DW), total flavonoid content (11–27 mg QE g−1 DW), total antioxidant activity (0.3–7 mg GAE g−1 DW) and free radical scavenging ability (DPPH assay, 64–927 µg extract g−1 at EC50) of obtained extracts were determined. Response surface methodology allowed obtaining predictive models for the extraction of each individual polyphenol. On the other hand, multifactorial ANOVA was used to establish differences between coffee and spent coffee ground extracts. Principal component analysis was also employed to relate antioxidant activities, total polyphenol and total flavonoid contents with both the polyphenols extracted and the residue coffee type. The overall results suggested that spent coffee grounds could be reused as a promising, inexpensive and natural source of bioactive polyphenols with potential industrial applications, thus minimizing the waste disposal and environmental impact.- Project number: 81
Item El enfoque STEM en la Formación Inicial de Maestros: pilas de combustible microbióticas(2018) Peña Martínez, Juan; Martínez Aznar, María Mercedes; Rosales Conrado, Noelia; Sánchez Gómez, Pedro; Rosa Novalbos, David; García Núñez, Iván; Sánchez Martín, Lorenzo Santiago; Rodríguez Arteche, ÍñigoEn el presente proyecto se introduce la metodología STEM en la formación inicial de maestros de Educación Primaria, a través de un conjunto de actividades experimentales de cinemática, dinámica, termología, ondas y electricidad/electrónica. Los experimentos han sido diseñados para expandir el uso de las tecnologías de la información y la comunicación (TIC) al tiempo que se fomenta el desarrollo de competencias, en ciencias y matemáticas, y el trabajo colaborativo. Para aumentar el bagaje en las TIC se emplea la plataforma Raspberry Pi, que se introduce progresivamente desde análisis estadístico de datos experimentales hasta uso de simuladores de fenómenos de ondas sonoras y de luz; y la tarjeta Arduino, que incluye un microcontrolador que puede programarse, para una mejor comprensión de los circuitos eléctricos. Además, se presentan en la sesión dedicada a la electricidad/electrónica, las pilas de combustible microbianas. Estos dispositivos pueden ilustrar el trabajo interdisciplinar de los científicos que luchan contra los cambios globales mundiales en términos de desarrollo sostenible. Es más, representan un excelente ejemplo para promover una correcta racionalidad ambiental. Item Citrus peels waste as a source of value-added compounds: Extraction and quantification of bioactive polyphenols(FOOD CHEMISTRY, 2019) Gómez Mejía, Esther; Rosales Conrado, Noelia; León González, María Eugenia De; Madrid Albarrán, María YolandaA method combining solid-liquid extraction based on ethanolic aqueous solution, cLC-DAD and chemometrics, was performed to extract and quantify polyphenols from citrus peels. LC-MS/MS was also employed for chemical profiling. The effect of extraction variables on the recovery was examined by experimental factorial design. Data were evaluated using multifactorial-ANOVA, response surface analysis and Principal Component Analysis. trans-Ferulic and p-coumaric antioxidants were found in lower quantities (<1.4 mg·g−1) in all peel extracts. Narangin flavonoid was also identified in all samples, while rutin flavonol was determined in the concentration range of 3.3–4.7 mg·g−1. The most abundant polyphenol in the extracts obtained from all evaluated citrus samples was the flavanone hesperidin (280–673 mg·g−1). Furthermore, peel extracts were evaluated in terms of total polyphenol and flavonoid content, total antioxidant activity and DPPH free radical scavenging. The obtained results suggested that evaluated citrus peel by-products could be reused as a source of polyphenols and transformed into value-added products.