Person:
Gómez Mejía, Esther

First Name

Esther

Last Name

Gómez Mejía

URI

https://hdl.handle.net/20.500.14352/86234

Affiliation

Universidad Complutense de Madrid

Faculty / Institute

Ciencias Químicas

Department

Química Analítica

Identifiers

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Now showing 1 - 10 of 22

Project number: 202
ODS con mucha ciencia: Hacia una enseñanza STEM y más allá
(2022) Gracia Lor, Emma; Blanco Asenjo, Miriam; Espada Bernabé, Elena; Fernández Bautista, Tamara; Gómez Castro, Emilio; Gómez Mejía, Esther; Gómez Gómez, Beatriz; Lorente Arévalo, Álvaro; Moreno Martín, Gustavo; Muñoz Olivas, María Riansares; Muñoz San Martín, Cristina; Oro Carretero, Paloma de; Pérez Corona, María Teresa; Romero Sánchez, Iván; Sacristán Navarro, Iván; Vicente Zurdo, David
Memoria del proyecto de innovación titulado "ODS con mucha ciencia: Hacia una enseñanza STEM y más allá" de la convocatoria 2021-2022. El proyecto se ha centrado en fomentar el interés de los estudiantes de ESO y Bachillerato por la ciencia, proporcionándoles herramientas para que desarrollen competencias STEM a través de charlas de divulgación, talleres experimentales y sesiones de mentoría.
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; ELSEVIER
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.
Valorization of prunus seed oils: fatty acids composition and oxidative stability
(Molecules, 2023) Rodríguez-Blázquez, Sandra; Gómez Mejía, Esther; Rosales Conrado, Noelia; León González, María Eugenia De; García-Sánchez, Beatriz; Miranda Carreño, Rubén
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.
A combined analytical-chemometric approach for the in vitro determination of polyphenol bioaccessibility by simulated gastrointestinal digestion
(Analytical and Bioanalytical Chemistry, 2022) Gómez Mejía, Esther; Rosales Conrado, Noelia; León González, María Eugenia; Valverde de la Fuente, Alejandro; Madrid Albarrán, Yolanda
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.
Valorization of citrus reticulata blanco peels to produce enriched wheat bread: phenolic bioaccessibility and antioxidant potential
(ANTIOXIDANTS, 2023) Gómez Mejía, Esther; Sacristán, Iván; Rosales Conrado, Noelia; León González, María Eugenia De; Madrid Albarrán, María Yolanda
The fortification of foods with bioactive polyphenols aims to improve their functional properties and to provide health benefits. Yet, to exert their benefits, phenolic compounds must be released from the food matrix and absorbed by the small intestine after digestion, so assessing their bioaccessibility is crucial to determine their potential role. This work aims to incorporate Citrus reticulata Blanco peel extracts into wheat bread as a promising opportunity to increase their bioactive potential, along with supporting the sustainable management of citrus-industry waste. A control and a wheat bread enriched at 2% and 4% (w/v) with a phenolic extract from mandarin peels were prepared and analyzed for antioxidant activity and phenolic composition using LC-MS and UV-Vis spectrophotometry. In addition, in vitro digestion was performed, and the digested extracts were analyzed with HPLC-MS/MS. The results showed a significant increase in total flavonoid content (TFC, 2.2 ± 0.1 mg·g−1), antioxidant activity (IC50 = 37 ± 4 mg·g−1), and contents of quercetin, caffeic acid, and hesperidin in the 4% (w/v) enriched bread. Yet, most polyphenols were completely degraded after the in vitro digestion process, barring hesperidin (159 ± 36 μg·g−1), highlighting the contribution of citrus enrichment in the development of an enriched bread with antioxidant potential.
Phenolic profile, safety, antioxidant and anti-inflammatory activities of wasted Bunium ferulaceum Sm. aerial parts
(Food Research International, 2022) Deghima, Amirouche; Righi, Nadjat; Rosales Conrado, Noelia; León González, María Eugenia De; Baali, Faiza; Gómez Mejía, Esther; Madrid Albarrán, María Yolanda; Bedjou, Fatiha; ELSEVIER
The pharmaceutical and nutraceutical industries benefit greatly from recycling and transforming non-utilized parts of medicinal plants from agro-industrial operations into value added products. Hence, the aim of this work was to study the potential nutraceutical and pharmaceutical applications of Bunium ferulaceum Sm. aerial parts, in order to maximize their value. The phenolic profile of their hydromethanolic extract was determined and its antioxidant activity was evaluated in vitro and in vivo alongside with its anti-inflammatory activity and safety profile. The extract exerted an in vitro antioxidant activity mainly through radical scavenging (DPPH IC50: 14.0 ± 0.3 μg/ml) and iron chelating ability (24 ± 2 μg/ml), while, in vivo, the extract did not cause any mortality or visible signs of acute toxicity at high dose (2000 mg/kg body weight). The supplementation of the extract at different doses improved mice liver redox state by increasing catalase and reduced glutathione levels and reducing lipid peroxidation, without causing any toxicity. Moreover, the extract efficiently inhibited xylene induced ear inflammation (62 %). These different bioactivities were linked to the phenolic compounds present in the extract, particularly, chlorogenic acid (78 ± 6 mg/g extract), rutin (44 ± 2 mg/g extract) and hesperidin (56 ± 9 mg/g extract). However, further studies should be carried out on the isolated major compounds found in the extract to correlate the activity with these compounds or their mixture. The wasted aerial parts of Bunium ferulaceum Sm. proved to be a valuable source of polyphenols and exhibited interesting health promoting effects with no toxicity. Thus, Bunium ferulaceum Sm. aerial parts can be included in nutraceutical formulations or used as functional food and the extracted compounds may be used as an alternative food preservative.
A Comprehensive Analytical Review of Polyphenols: Evaluating Neuroprotection in Alzheimer’s Disease
(International Journal of Molecular Sciences, 2024) Vicente Zurdo, David; Gómez Mejía, Esther; Rosales Conrado, Noelia; León González, María Eugenia De
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.
Effect of Storage and Drying Treatments on Antioxidant Activity and Phenolic Composition of Lemon and Clementine Peel Extracts
(Molecules, 2023) Gómez Mejía, Esther; Sacristán Navarro, Iván; Rosales Conrado, Noelia; León González, María Eugenia De; Madrid Albarrán, María Yolanda
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-DADMS, 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.
Screening the extraction process of phenolic compounds from pressed grape seed residue: Towards an integrated and sustainable management of viticultural waste
(LWT - Food Science and Technology, 2022) Gómez Mejía, Esther; Vicente Zurdo, David; Rosales Conrado, Noelia; León González, María Eugenia; Madrid Albarrán, Yolanda
The integrated valorisation of waste from the food chain to obtain value-added compounds with biological functionality will facilitate the transition to the era of a sustainable bioeconomy. To this end, an efficient matrix solid-phase dispersion (MSPD) extraction method was developed and optimized, using experimental factorial design and response surface methodology, for polyphenols recovery from pressed grape seeds obtained after the extraction of essential oils by cold pressing. Gallic, dihydroxybenzoic, p-coumaric and trans-ferulic acid, naringin, resveratrol, quercetin and kaempferol were quantified at 2.1–295 μg g−1 by capillary liquid chromatography coupled to a diode array detector and a mass analyser (cLC-DAD-MS). Furthermore, total antioxidant activity, free radical scavenging and lipid peroxidation suppression, together with the inhibition of beta-amyloid (Αβ42) protein aggregation, considered one of the main pathological effects of Alzheimer's disease, were evaluated. Potent lipid peroxidation inhibition (IC50 0.238 ± 0.003 ng g−1) was observed, along with the reduction of Αβ42 fibril width (9.4–54.8%) and aggregation. The results presented proved that the MSPD extraction method could be considered as an efficient and sustainable methodology to produce phenolic-rich extracts that may serve as an alternative antioxidant and neuroprotective ingredient for the food or pharmaceutical formulations, leading to the cascade valorisation of winery by-products.
Aprendizaje-Servicio para trasladar los resultados desarrollo sostenible: del laboratorio a la sociedad
(2021) Gracia Lor, Emma; Gómez Mejía, Esther; Moreno Martín, Gustavo; Gómez Gómez, Beatriz; Vicente Zurdo, David; Pérez Corona, María Teresa; Muñoz Olivas, María Riansares; Gómez Castro, Emilio
El objetivo general planteado en este proyecto ha sido comunicar y concienciar a los estudiantes de secundaria y bachillerato sobre la necesidad de un desarrollo sostenible, con el fin de que sean capaces de comprender e identificar las problemáticas asociadas a los objetivos planteados en la Agenda 2030 y asociarlas con actividades propias de la vida cotidiana. De esta manera, los alumnos podrán adquirir herramientas de gran utilidad para el desarrollo de su futura vida personal y profesional. Para lograr dichos objetivos se han llevado a cabo una serie de actividades (charlas de divulgación científica, debates, uso de la aplicación Kahoot) en diferentes centros educativos no universitarios, en concreto, en tres institutos de educación secundaria y bachillerato (IES) y en un centro de educación de personas adultas (CEPA). Los temas tratados se encuadran dentro de los Objetivos de Desarrollo Sostenible (ODS) de la Agenda 2030, concretamente los ODS 2, 3 y 12.