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Alzheimer’s Disease (AD), a prevalent neurodegenerative disorder, is the primary cause of dementia. Despite significant advancements in neuroscience, a definitive cure or treatment for this debilitating disease remains elusive. A notable characteristic of AD is oxidative stress, which has been identified as a potential therapeutic target. Polyphenols, secondary metabolites of plant origin, have attracted attention due to their potent antioxidant properties. Epidemiological studies suggest a correlation between the consumption of polyphenol-rich foods and the prevention of chronic diseases, including neurodegenerative disorders, which underscores the potential of polyphenols as a therapeutic strategy in AD management. Hence, this comprehensive review focuses on the diverse roles of polyphenols in AD, with a particular emphasis on neuroprotective potential. Scopus, ScienceDirect, and Google Scholar were used as leading databases for study selection, from 2018 to late March 2024. Analytical chemistry serves as a crucial tool for characterizing polyphenols, with a nuanced exploration of their extraction methods from various sources, often employing chemometric techniques for a holistic interpretation of the advances in this field. Moreover, this review examines current in vitro and in vivo research, aiming to enhance the understanding of polyphenols’ role in AD, and providing valuable insights for forthcoming approaches in this context., Depto. de Química Analítica, Fac. de Ciencias Químicas, TRUE, pub

Se ha creado un espacio universitario donde, gracias a destacados especialistas en paz, desarrollo, seguridad y educación transformadora, se han aportado enfoques y prácticas para afrontar los desafíos de la convivencia social e impulsar la cultura de la paz, todo ello muy necesario para la formación inicial de maestros y maestras. Por otro lado, se ha facilitado y experimentado una propuesta didáctica orientada a promover el dialogo y respeto mutuo en el ámbito de la Didáctica de la Química. Finalmente, se ha llevado a cabo un estudio exploratorio sobre la actitud de los futuros docentes (estudiantes de la Facultad de Educación - Centro de Formación del Profesorado de la Universidad Complutense de Madrid) hacia la paz y la guerra.

A 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., Comunidad de Madrid Programa FEDER, Ministerio de Economía y Competitividad, Universidad Complutense de Madrid, Depto. de Química Analítica, Fac. de Ciencias Químicas, TRUE, pub

Due to the extensive use of Ranunculus macrophyllus Desf. roots for medicinal purposes, most of the leafy green parts are just wasted. The aim of this work is to valorize the leafy green parts and promote their application in different modern industries. Methods For this purpose, we studied the phenolic profile of R. macrophyllus Desf. (RM-B) using chromatographic and spectrophotometric methods and we tested the in-vitro antioxidant activity and the in-vivo effect of RM-B on plasma and liver antioxidant statuts. Results RM-B contained high amounts of polyphenols (675 mg GAE/100 g dry weigh dw) and flavonoids (105 mg QE/100 g dw). In-vitro, RM-B exhibited promising radical scavenging activity against 2,2′-azino-bis(3-éthylbenzothiazoline-6-sulphonique) (ABTS+·) (IC50: 247 µg/mL), hydrogen peroxide radicals (IC50: 626 µg/mL) and inhibited oxidative red blood cells hemolysis (IC50: 120 µg/mL), RM-B also showed strong reducing power (982 µM FeSO4/mg extract). In-vivo, RM-B improved the radical scavenging ability and reducing power of plasma and enhanced liver antioxidant status by increasing catalase and reduced glutathione levels and decreasing malondialdhyde levels without altering the key serum biochemical parameters reflecting liver and kidney functions. Polyphenols identified using capillary LC-DAD and LC–MS/MS analyses like hesperidin (131.2 mg/100 g dw), rutin (29.0 mg/100 g dw) and p-coumaric acid (5.8 mg/100 g dw), may be responsible for the health promoting effects of RM-B. Conclusion We may conclude that R. macrophyllus Desf. is a good source of beneficial polyphenols with strong antioxidant, anti-hemolytic and health-promoting effects, which promotes its use in pharmaceutical, medicinal and nutraceutical industries., Community of Madrid/ FEDER program, Ministry of Economy and Competitiveness, Depto. de Química Analítica, Fac. de Ciencias Químicas, TRUE, pub

Obtaining polyphenols from horticultural waste is an emerging trend that enables the valorization of resources and the recovery of value-added compounds. However, a pivotal point in the exploitation of these natural extracts is the assessment of their chemical stability. Hence, this study evaluates the effect of temperature storage (20 and −20 °C) and drying methods on the phenolic composition and antioxidant activity of clementine and lemon peel extracts, applying HPLC-DAD-MS, spectrophotometric methods, and chemometric tools. Vacuum-drying treatment at 60 °C proved to be rather suitable for retaining the highest antioxidant activity and the hesperidin, ferulic, and coumaric contents in clementine peel extracts. Lemon extracts showed an increase in phenolic acids after oven-drying at 40 °C, while hesperidin and rutin were sustained better at 60 °C. Hydroethanolic extracts stored for 90 days preserved antioxidant activity and showed an increase in the total phenolic and flavonoid contents in lemon peels, unlike in clementine peels. Additionally, more than 50% of the initial concentration was maintained up to 51 days, highlighting a half-life time of 71 days for hesperidin in lemon peels. Temperature was not significant in the preservation of the polyphenols evaluated, except for in rutin and gallic acid, thus, the extracts could be kept at 20 °C., Community of Madrid/FEDER program, Ministry of Science, Innovation and Universities, Depto. de Química Analítica, Fac. de Ciencias Químicas, TRUE, pub

A 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., Comunidad de Madrid Programa FEDER, Ministerio de Economía y Competitividad, Universidad Complutense de Madrid, Depto. de Química Analítica, Fac. de Ciencias Químicas, TRUE, pub

This paper introduces a captivating topic for upper-level analytical chemistry capstone projects, focusing on aquarium water analysis. This provides a more comprehensive understanding of the role of analytical chemistry towards sustainability and its environmental, economic, societal and education dimensions. Regarding the crucial role of maintaining optimal aquarium water quality for the welfare of aquatic life, students are tasked with envisioning and executing the measurement of key parameters, including pH, ammonium, nitrite, and nitrate contents. This hands-on experience not only engages students in real-world applications, but also allows them to delve into essential analytical chemistry principles. They carefully select measurement methods, considering factors such as instrument availability, ease of use, precision and sensitivity requirements, sample size, and matrix effects. Besides fostering the acquisition of technical and soft skills, one notable aspect of this type of project is the exceptionally high student satisfaction. Furthermore, the project’s outcomes have proven to be significant predictors of learning achievements. Additionally, it lays the foundation for exploring potential designs of aquaponics systems and fosters interdisciplinary projects, expanding the practical applications in the field of chemistry education. Overall, these projects exemplify enriching and engaging educational experiences that empower students with valuable skills and knowledge while encouraging them to explore novel avenues in analytical chemistry., Universidad Complutense de Madrid, Depto. de Química Analítica, Depto. de Didáctica de las Ciencias Experimentales , Sociales y Matemáticas, Fac. de Ciencias Químicas, Fac. de Educación, TRUE, pub

Prunus fruit seeds are one of the main types of agri-food waste generated worldwide during the processing of fruits to produce jams, juices and preserves. To valorize this by-product, the aim of this work was the nutritional analysis of peach, apricot, plum and cherry seeds using the official AOAC methods, together with the extraction and characterization of the lipid profile of seed oils using GC-FID, as well as the measurement of the antioxidant activity and oxidative stability using the 2,2-diphenyl-1-picrylhydrazyl (DPPH) free-radical scavenging method. Chemometric tools were required for data evaluation and the obtained results indicated that the main component of seeds were oils (30–38%, w). All seed oils were rich in oleic (C18:1n9c) and linoleic (C18:2n6c) acids and presented heart-healthy lipid indexes. Oil antioxidant activity was estimated in the range IC50 = 20–35 mg·mL−1, and high oxidative stability was observed for all evaluated oils during 1–22 storage days, with the plum seed oil being the most antioxidant and stable over time. Oxidative stability was also positively correlated with oleic acid content and negatively correlated with linoleic acid content. Therefore, this research showed that the four Prunus seed oils present interesting healthy characteristics for their use and potential application in the cosmetic and nutraceutical industries., Ministry of Science and Innovation, the state research agency and the European Union NextGenerationEU/PRTR, Depto. de Química Analítica, Fac. de Ciencias Químicas, TRUE, pub

A 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., Community of Madrid/FEDERprogram, Ministry ofEconomy and Competitiveness, Complutense University, Depto. de Química Analítica, Fac. de Ciencias Químicas, TRUE, pub

A 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., Spanish Commission of Science and Technology, Comunidad of Madrid and European funding from FSE and FEDER programs, Depto. de Química Analítica, Fac. de Ciencias Químicas, TRUE, pub

A 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., Comunidad de Madrid Programa FEDER, Ministerio de Economía y Competitivad, Depto. de Química Analítica, Fac. de Ciencias Químicas, TRUE, pub

The integrated valorization of food chain waste is one of the most promising alternatives in the transition to a sustainable bioeconomy. Thus, an efficient solid-phase matrix dispersion extraction method, using experimental factorial design and response surface methodology, has been developed and optimized for the recovery of polyphenols from defatted cherry seeds obtained after cherry liquor manufacture and subsequent fatty acid extraction, evaluating the effect of each processing step on the composition and phenolic content of sweet cherry residues. The phenolic extracts before fermentation showed the highest content of total polyphenols (TPC) and flavonoids (TFC) (3 ± 1 mg QE·g−1 and 1.37 ± 0.08 mg GAE·g−1, respectively), while the highest antioxidant capacity was obtained in the defatted seed extracts after both fermentation and distillation. In addition, high-performance liquid chromatography coupled to a quadrupole time-of-flight mass spectrometer (HPLC-ESI-QTOF-MS) was used to determine the phenolic profile. Dihydroxybenzoic acid, neochlorogenic acid, caffeic acid, and quercetin were the main phenolics found, showing differences in concentration between the stages of liquor production. The results underline the prospective of cherry by-products for obtaining phenol-rich bioactive extracts for possible use in different industrial sectors, offering a feasible solution for the cascade valorization of cherry agri-food waste., Depto. de Química Analítica, Depto. de Ingeniería Química y de Materiales, Fac. de Ciencias Químicas, TRUE, pub, Descuento UCM

Alzheimer’s disease (AD) is a devastating neurodegenerative disorder characterized by progressive cognitive decline and the accumulation of beta-amyloid plaques and tau tangles in the brain. Current therapies have limited efficacy, prompting the search for novel treatments. Selenium nanoparticles (SeNPs) have emerged as promising candidates for AD therapy due to their unique physicochemical properties and potential therapeutic effects. This review provides an overview of SeNPs and their potential application in AD treatment, as well as the main bioanalytical techniques applied in this field. SeNPs possess antioxidant and anti-inflammatory properties, making them potential candidates to combat the oxidative stress and neuroinflammation associated with AD. Moreover, SeNPs have shown the ability to cross the blood-brain barrier (BBB), allowing them to target brain regions affected by AD pathology. Various methods for synthesizing SeNPs are explored, including chemical,physical and biological synthesis approaches. Based on the employment of algae, yeast, fungi, and plants, green methods offer a promising and biocompatible alternative for SeNPs production. In vitro studies have demonstrated the potential of SeNPs in reducing beta-amyloid aggregation and inhibiting tau hyperphosphorylation, providing evidence of their neuroprotective effects on neuronal cells. In vivo studies using transgenic mousem models and AD-induced symptoms have shown promising results, with SeNPs treatment leading to cognitive improvements and reduced amyloid plaque burden in the hippocampus. Looking ahead, future trends in SeNPs research involve developing innovative brain delivery strategies to enhance their therapeutic potential, exploring alternative animal models to complement traditional mouse studies, and investigating multi-targeted SeNPs formulations to address multiple aspects of AD pathology. Overall, SeNPs represent a promising avenue for AD treatment, and further research in this field, Ministerio de Ciencia, Innovación y Universidades (España), Depto. de Química Analítica, Fac. de Ciencias Químicas, TRUE, pub

With the final objective of using computational and chemometrics tools in the chemistry studies, this paper shows the methodology and interpretation of the Principal Component Analysis (PCA) using pollution data from different cities. This paper describes how students can obtain data on air quality and process such data for additional information related to the pollution sources, climate effects, and social aspects over pollution levels by using a powerful chemometrics tool such as principal component analysis (PCA). The paper could also be useful for students interested in environmental chemistry and pollution interpretation; this statistical method is a simple way to display visually as much as possible of the total variation of the data in a few dimensions, and it is an excellent tool for looking into the normal pollution patterns., Depto. de Química Analítica, Fac. de Ciencias Químicas, TRUE, pub

Las enfermedades neurodegenerativas se caracterizan por un progresivo deterioro en los aspectos cognitivos, como la memoria, el lenguaje, el comportamiento y la capacidad ejecutiva, siendo el envejecimiento el principal factor de riesgo. Suponen un gran reto parala sociedad, ya que son el primer motivo de discapacidad y la segunda causa de muerte a nivel global. Actualmente, afectan a más de 50 millones de personas en todo el mundo, con solo el 25% de los pacientes diagnosticados oficialmente, y estando previsto que alcancen los 152 millones de afectados para el año 2050. Por el momento no hay tratamientos efectivos para estos desórdenes neurológicos, con el consiguiente elevado coste socioeconómico que ello conlleva. Las cuatro enfermedades neurodegenerativas más frecuentes son la enfermedad de Alzheimer (AD), la enfermedad de Parkinson (PD), la esclerosis lateral amiotrófica (ALS) y la enfermedad de Huntington (HD). De entre ellas, la AD es la más prevalente, representando un 80% del total de los casos de demencia..., Neurodegenerative diseases are characterised by a progressive impairment incognitive aspects such as memory, language, behaviour, and executive capacity, with ageing being the main risk factor. They represent a major challenge for society since they are the leading cause of disability and the second leading cause of death globally. Currently, they affect more than 50 million people worldwide, with only 25% of patients officially diagnosed, and projected to reach 152 million by 2050. Now, there are no effective treatments for these neurological disorders, with the resulting high socio-economic costs. The four most widespread neurodegenerative diseases are Alzheimer's disease (AD), Parkinson's disease (PD), amyotrophic lateral sclerosis (ALS) and Huntington's disease(HD). Among these, AD is the most prevalent, representing 80% of the total number of dementia cases..

Referencias bibliográficas: • Baepler, P.,Walker, J. D.,Driessen, M.. (2014). It’s not about seat time: Blending, flipping, and efficiency in active learning classrooms. Computers & Education. 78. 227 • Barkley, E.,Cross, K.,Howel, C.. (2007). Técnicas de Aprendizaje Colaborativo. Ediciones Morata. Madrid. • Bergmann, J.,Sams, A.. (2009). Remixing chemistry class. Learning & Leading With Technology. 36. 22 • Cañadas, I.,Sánchez, A.. (1998). Categorías de respuestas en escalas tipo Likert. Psicothema. 10. 621 • Castro, A. R.,Moreno, M. C.,Simonet, B. M.. (2012). Técnicas espectroscópicas en química analítica. Volumen I. Aspectos básicos y espectrometría molecular. Síntesis, S.A.. Madrid. • Castro, A. R.,Moreno, M. C.,Simonet, B. M.. (2012). Técnicas espectroscópicas en química analítica. Volumen II. Espectrometría atómica de iones y electrones. Síntesis, S.A.. Madrid. • Dafonte-Gómez, A.,Míguez-González, M. I.,Corbacho-Valencia, J. M.. (2017). La investigación internacional sobre flipped learning en revistas académicas. Estado de la cuestión. III Congreso Internacional de Educación Mediática y Competencia Digital. 2017. • Durán-García, M. E.,Durán-Aponte, A. A.. (2013). La termodinámica en los estudiantes de tecnología: una experiencia de aprendizaje cooperativo. Enseñanza de las ciencias. 31. 45-59 • (2014). Flipped Learning Network. The Four Pillars of F-L-I-P™. • Fornons, V.,Palau, R. F.. (2016). Flipped classroom en la asignatura de matemáticas de 3 de educación secundaria obligatoria. Edutec-e. Revista Electrónica de Tecnología Educativa. 55. • Fulton, K.. (2012). Upside down and inside out: Flip your classroom to improve student learning. Learning & Leading with Technology. 39. 12 • Galloway, K.R.,Malakpa, Z.,Lowery, S.. (2016). Investigating affective experiences in the undergraduate chemistry laboratory: student´s perceptions of control and responsibility. Journal of Chemical Education. 93. 227 • González Gómez, D.,Jeong, J. S.,Cañada Cañada, F.,Gallego Picó, En el presente trabajo se describe una experiencia didáctica en un curso de Bachillerato, perteneciente al Programa de Excelencia, de un centro escolar de la Comunidad de Madrid (España). Mediante un modelo de clase invertida o flipped classroom (de su traducción en inglés), se abordaron los fundamentos relacionados con las técnicas de análisis espectroscópico y se realizaron actividades experimentales como la preparación de un espectroscopio “casero”. Tras la intervención, se llevó a cabo una encuesta de satisfacción para conocer la percepción de los estudiantes sobre las actividades realizadas y sobre el modelo de enseñanza-aprendizaje aplicado. Los alumnos han valorado positivamente la nueva metodología, si bien, su aplicación ha generado un cierto desconcierto que puede generar dudas a la hora de aplicar el enfoque de clase invertida a otras asignaturas., A didactic experience addressed to a class of outstanding college students of Madrid (Spain) is presented in this work. The instruction was devoted to spectroscopy analysis techniques following a flipped classroom model i.e. some experimental activities such as a home spectroscope preparation were carried out. After the instruction, the students’ perception of the activities and the proposed learning-teaching model was analysed trough a satisfaction survey. Although there is a positive assessment of the new methodology, its application to other subjects must be reconsidered taking into account the confusion created in the students., Depto. de Didáctica de las Ciencias Experimentales , Sociales y Matemáticas, Fac. de Educación, TRUE, pub

Referencias bibliográficas: • Alonso, M. J.,Ortiz, Y.. (2005). Del cuaderno de equipo al método de proyectos. Cuadernos de Pedagogía. 345. 62 • Balocchi, E.,Modak, B.,Martínez-M., M.,Padilla, K.,Reyes-C, F.,Garritz, A.. (2005). Aprendizaje cooperativo del concepto ‘cantidad de sustancia’ con base en la teoría atómica de Dalton y la reacción química. Parte I. El aprendizaje cooperativo. Anexo: cuadernillo ‘La reacción química y su representación’. Educación Química. 16. 469 • Balocchi, E.,Modak, B.,Martínez-M., M.,Padilla, K.,Reyes-C, F.,Garritz, A.. (2005). Parte II: Concepciones alternativas de ‘reacción química’ Anexo: cuadernillo ‘Masas atómicas relativas de los elementos’. Educación Química. 16. 550 • Balocchi, E.,Modak, B.,Martínez-M., M.,Padilla, K.,Reyes-C, F.,Garritz, A.. (2006). Parte III: Concepciones acerca de la ‘cantidad de sustancia’ y su unidad ‘el mol’. Anexo: Cuadernillo ‘Cantidad de sustancia’. Educación Química. 17. 14-32 • Carbonell, F.,Furió, C.. (1987). Opiniones de los adolescentes respecto del cambio sustancial en las reacciones químicas. Enseñanza de las ciencias. 5. 3-9 • Cooper, M. M.. (1995). Cooperative Learning. An Approach for Large Enrolment Courses. Journal of Chemical Education. 72. 162 • De Prada, F. I.,Cañas, A.,Caamaño, A.. (2015). Física y Química. ESO. Savia. Grupo SM Educación. • Dávila, M. A.,Cañada, F.,Sánchez, J.,Mellado, V.. (2016). Las emociones en el aprendizaje de física y química en educación secundaria. Causas relacionadas con el estudiante. Educación Química. 27. 217 • Dávila, M. A.,Cañada, F.,Sánchez, J.. (2017). Aprendizaje cognitivo y emocional de las reacciones químicas. Alambique. Didáctica de las Ciencias Experimentales. 90. 27-36 • De Ita Cisneros, M. A.,González Vergara, E.. (2005). ¿H2O igual a agua?: Una experiencia de aprendizaje colaborativo en el aula o el laboratorio. Educación Química. 16. 39-43 • De Vos, W.,Verdonk, A. H.. (1985). A New Road to Reactions. Journal of Chemical Education. 62. 238 • Diaz, En el presente trabajo se propone una secuencia didáctica para la enseñanza de las reacciones químicas en educación secundaria, que incluye dos actividades diferentes de aprendizaje cooperativo. La primera, para trabajar la diferencia entre cambio físico y cambio químico y, la segunda, para consolidar la parte experimental que también se ha llevado a cabo en el laboratorio. Un total de 43 estudiantes valoraron la experiencia y la metodología empleada mediante un cuestionario. Los resultados muestran que aproximadamente un 80% están a favor de emplear el modelo de aprendizaje con grupos cooperativos. No obstante, un 30% de los estudiantes señalan que hay que asegurar que todos los miembros de los equipos participen y realicen el trabajo asignado. La metodología cooperativa se podría emplear en la enseñanza de las reacciones químicas., In this research, we propose a didactic sequence for teaching chemical reactions in secondary education, which includes two different cooperative learning activities. The first one aims to work the differences between physical change and chemical change, and the second activity intends to consolidate the experimental job that was carried out in the laboratory. A total of 43 students completed a questionnaire to assess the experience and the methodology used. Results show that around 80% of the participants are willing to learn in cooperative groups, nevertheless 30% of students pointed out that teachers should encourage that each team member equally participates and shares the workload. Cooperative strategies might be useful for teaching chemical reactions., Depto. de Didáctica de las Ciencias Experimentales , Sociales y Matemáticas, Fac. de Educación, TRUE, pub

CRUE-CSIC (Acuerdos Transformativos 2022), In this study, an integrated characterisation through polyphenol and cafeine content and antioxidant activity was combined with chemometric analysis to assess the efects of simulated in vitro gastrointestinal digestion on the bioaccessibility of these bioactive compounds from nine diferent tea infusions. Tea infusions were characterised based on total favonoids, total polyphenols and antioxidant activity, together with the determination of individual polyphenol content. Fourteen phenolic compounds, including phenolic acids, stilbenes and favonoids, were selected based on their reported bioactivity and high accessibility, attributed to their low molecular weight. Both polyphenols and cafeine were initially monitored in raw tea infusions and through the diferent digestion stages (salivary, gastric and duodenal) by capillary high performance liquid chromatography coupled to diode array detection (cHPLC-DAD) and/or HPLC coupled to a triple quadrupole mass analyser (HPLC–MS/MS). Multivariate analysis of the studied bioactives, using principal component analysis and cluster analysis, revealed that the decafeination process seems to increase the stability and concentration of the compounds evaluated during digestion. The greatest transformations occurred mainly in the gastric and duodenal stages, where low bioactivity indices (IVBA) were shown for resveratrol and cafeic acid (IVBA=0%). In contrast, the polyphenols gallic acid, chlorogenic acid and quercetin gave rise to their availability in white, green and oolong infusion teas (IVBA>90%). Furthermore, highly fermented black and pu-erh varieties could be designated as less bioaccessible environments in the duodenum with respect to the tested compounds., Ministerio de Ciencia e Innovación (MICINN), Comunidad de Madrid/FEDER, Universidad Complutense de Madrid, Depto. de Química Analítica, Fac. de Ciencias Químicas, TRUE, pub