http://hdl.handle.net/10366/137252 2026-04-24T15:56:44Z http://hdl.handle.net/10366/165890 [EN]The phenolic composition of the extractable fraction of Zalema grape pomace has been analyzed by HPLC-DADMS and consisted of mainly flavanols and flavonols (122.75 and 23.11 mg/100 g dry pomace, respectively). The antioxidant activity has been determined by in vitro FRAP, ABTS, and ORAC assays (11.7, 34.9, and 63.6 mmol of Trolox equivalents (TE) per 100 g of dry pomace, respectively) and in vivo using the model organism Caenorhabditis elegans. Cultivation of C. elegans in media containing 100 μg/mL dry pomace extract increased the survival of worms submitted to thermally induced oxidative stress, whereas a decrease in the rate of worm survival was found for 300 μg/mL extract. Interestingly, the levels of reactive oxygen species (ROS) were significantly decreased in stressed worms treated with the pomace extract at the two concentration levels. Further studies are required to explain this unexpected behavior, as well as to determine the compounds and mechanisms involved in the observed effects. 2013-01-01T00:00:00Z http://hdl.handle.net/10366/165889 [EN]Cigarette smoking has been associated with an increase in oxidative stress (OS) and is considered a predisposing factor to chronic noncommunicable diseases, whilst dietary antioxidants has been proposed as an alternative to cope with this oxidative stress. In this study, 20 smokers and 20 non-smokers were studied with the aim of determining their antioxidant status, as well as the ability of an infusion of 23 medicinal plants, to counteract the damage caused by OS. The plasma, red blood cells (RBCs) and polymorphonuclear cells (PBMCs) of both groups were incubated or not with the horchata infusion extract and then the OS markers, genotoxicity, nanostructure of RBCs membrane and genes related to oxidative responses and cellular functionality were evaluated. Up to 33 different compounds, mainly quercetin glycosides, were identified in the extract. A significant deterioration in the antioxidant status in smokers compared to non-smokers was found. The horchata infusion extract improved the nanostructure of RBCs and DNA damage, as well as the activity of the endogenous antioxidant enzymes and markers of oxidative damage to lipid, and proteins in plasma, RBCs and PBMCs in both groups, whilst no significant changes were found in the expression of different genes related to OS response. 2020-01-01T00:00:00Z http://hdl.handle.net/10366/165844 We tested whether the administration procedure of quercetin affects its metabolite profile and antihypertensive activity. Spontaneously hypertensive rats (SHR) were randomly assigned to four experimental treatments: (1) 1 mL of 1% methylcellulose by oral gavage and 2% DMSO i.p. (control group); (2) 10 mg kg-1 quercetin by oral gavage once daily and 2% DMSO i.p.; (3) 10 mg kg-1 quercetin by oral gavage divided in two daily doses (5 + 5 at 12 h intervals) and 2% DMSO i.p.; (4) 1 mL of 1% methylcellulose by oral gavage and 10 mg kg-1 quercetin i.p. injection. Rats were treated daily for 5 weeks. Single dose and two daily doses, in a long-term oral treatment were equally efficient, both restoring the impaired aortic endothelium-dependent vasodilatation and reducing mesenteric contractile response to phenylephrine, systolic blood pressure, heart rate, and heart and kidney hypertrophy. Attenuation of vascular NADPH oxidase-driven O2- production was also found in orally treated rats. Intraperitoneal administration reduced, to lesser extent than oral administration, the increased systolic blood pressure, being without effect to the endothelial dysfunction and vascular oxidative stress. In contrast, greater levels of metabolites were quantified following intraperitoneal compared to oral administration at any time point, except for higher plasma methylated quercetin aglycone in oral as compared to intraperitoneal administration at 2 but not at 8 h. In conclusion, oral quercetin was superior to intraperitoneal administration for the protection from cardiovascular complications in SHR. No differences were found between the oral administration as a single daily dose or divided into two daily doses. 2012-01-01T00:00:00Z http://hdl.handle.net/10366/165818 [EN] Background: Anthocyanins are a major class of plant phenolic pigments, responsible for the red, purple or blue color of leaves, flowers, tubers, fruits and certain vegetables. They are considered the largest and most important group of water-soluble pigments in nature and have been described to have multiple health-promoting properties. However, the bioavailability of anthocyanins is reportedly extremely low, affected by factors inherent to the molecule's characteristics, as well as by the effect of food processing, transformations during the digestive process and their levels in fruits. Scope and approach: This review aims to discuss current knowledge regarding the effects of technological processes used in the food industry on the stability, bioavailability and biological effect of anthocyanins. In addition, a review of new trends in the improvement of anthocyanin production in plants is presented, which outlines what has been reported about genes involved in the regulation and its expression. Key findings and conclusions: The alterations that anthocyanins suffer, which can affect their bioavailability and biological effects, do not take place solely during the digestion process, caused mainly by pH and intrinsic and bacterial enzymes, but also during the different processing methods that food-containing anthocyanins can undergo. Factors such as thermal and non-thermal processing, storage, oxidative degradation and encapsulation systems have been shown to closely influence anthocyanins' stability and biological effects. In recent times, genetic manipulation aiming at upregulating the gene expression of metabolic pathways has been used to improve fruit quality and anthocyanin content in plant foods, and may also contribute towards counteracting some of the indicated limitations.; [ES] Fondo: Las antocianinas son una clase importante de pigmentos fenólicos vegetales , responsables del color rojo, morado o azul de hojas, flores, tubérculos, frutas y ciertas verduras. Se consideran el grupo más grande e importante de pigmentos hidrosolubles en la naturaleza y se les han descrito múltiples propiedades beneficiosas para la salud. Sin embargo, se ha informado que su biodisponibilidad es extremadamente baja, afectada por factores inherentes a las características de la molécula, así como por el efecto del procesamiento de los alimentos, las transformaciones durante el proceso digestivo y sus niveles en las frutas. Alcance y enfoque: Esta revisión tiene como objetivo analizar el conocimiento actual sobre los efectos de los procesos tecnológicos empleados en la industria alimentaria en la estabilidad, la biodisponibilidad y el efecto biológico de las antocianinas. Además, se presenta una revisión de las nuevas tendencias en la mejora de la producción de antocianinas en plantas, que describe lo que se ha reportado sobre los genes implicados en su regulación y expresión . Hallazgos y conclusiones clave: Las alteraciones que sufren las antocianinas, que pueden afectar su biodisponibilidad y efectos biológicos, no ocurren únicamente durante el proceso de digestión, causado principalmente por el pH y las enzimas intrínsecas y bacterianas , sino también durante los diferentes métodos de procesamiento a los que pueden someterse las antocianinas que contienen alimentos. Se ha demostrado que factores como el procesamiento térmico y no térmico, el almacenamiento, la degradación oxidativa y los sistemas de encapsulación influyen estrechamente en la estabilidad y los efectos biológicos de las antocianinas. Recientemente, la manipulación genética con el objetivo de regular positivamente la expresión génica de las vías metabólicas se ha utilizado para mejorar la calidad de la fruta y el contenido de antocianinas en alimentos vegetales, y también puede contribuir a contrarrestar algunas de las limitaciones indicadas. 2021-01-01T00:00:00Z http://hdl.handle.net/10366/165817 [EN] Quercetin is a major flavonoid in the human diet and the most commonly used in studies of biological activity. Most of the knowledge about its biological effects has originated from in vitro studies while in vivo data are scarce. Quercetin mostly occurs in foodstuffs as glycosides that are deglycosylated during absorption and further submitted to different conjugation reactions. Methylation to isorhamnetin (quercetin 3'-O-methylether) or tamarixetin (quercetin 4'-O-methylether) seems to be an important conjugation process in quercetin metabolism. In this work, the effects of quercetin and its 3'-and 4'-O-methylated metabolites on the phenotypic characteristics, stress oxidative resistance, thermotolerance and lifespan of the model organism Caenorhabditis elegans have been assessed. The three assayed flavonols significantly prolonged the lifespan of this nematode with an increase from 11% to 16% in the mean lifespan with respect to controls. However, only quercetin significantly increased the reproductive capacity of the worm and enlarged the body size. Exposure to the assayed flavonols also increased significantly the resistance against thermal and juglone-induced oxidative stress, although differences were found depending on the stage of development of the worm. Thus, quercetin offered greater protection when thermal stress was applied in the 1st day of adulthood, whereas tamarixetin was more efficient in worms submitted to stress in the 6th day of adulthood. Similarly, significantly greater protection was provided by quercetin than by its methylated derivatives at the 1st day of adulthood, whilst quercetin and isorhamnetin were equally efficient when the oxidative stress was induced in the 6th of day of adulthood. Further evidence of antioxidant protection was obtained checking the oxidation status of proteins by the OxyBlot detection kit. Analyses by HPLC-DADESI/MS confirmed that the three flavonols were taken up by C. elegans leading to the formation of some glycosylated, sulfated and methylated metabolites, and that demethylation of these latter to quercetin was also produced. Quantification of the levels of quercetin, isorhamnetin and tamarixetin, as well as their detected metabolites indicated a greater uptake of quercetin than its methylated derivatives by the nematode.; [ES] La quercetina es un flavonoide importante en la dieta humana y el más comúnmente utilizado en estudios de actividad biológica. La mayor parte del conocimiento sobre sus efectos biológicos proviene de estudios in vitro, mientras que los datos in vivo son escasos. La quercetina se encuentra principalmente en alimentos como glicósidos que se desglicosilan durante la absorción y posteriormente se someten a diferentes reacciones de conjugación. La metilación a isorhamnetina (quercetina 3'-O-metiléter) o tamarixetina (quercetina 4'-O-metiléter) parece ser un proceso de conjugación importante en el metabolismo de la quercetina. En este trabajo, se han evaluado los efectos de la quercetina y sus metabolitos 3' y 4'-O-metilados sobre las características fenotípicas, la resistencia oxidativa al estrés, la termotolerancia y la longevidad del organismo modelo Caenorhabditis elegans. Los tres flavonoles analizados prolongaron significativamente la vida útil de este nematodo, con un aumento del 11% al 16% en la vida media con respecto a los controles. Sin embargo, solo la quercetina incrementó significativamente la capacidad reproductiva del gusano y aumentó su tamaño corporal. La exposición a los flavonoles analizados también aumentó significativamente la resistencia al estrés oxidativo inducido por juglona y térmico, aunque se observaron diferencias según la etapa de desarrollo del gusano. Así, la quercetina ofreció mayor protección cuando se aplicó estrés térmico en el primer día de edad adulta, mientras que la tamarixetina fue más eficaz en gusanos sometidos a estrés en el sexto día de edad adulta. De igual manera, la quercetina proporcionó una protección significativamente mayor que sus derivados metilados en el primer día de edad adulta, mientras que la quercetina y la isorhamnetina fueron igualmente eficaces cuando el estrés oxidativo se indujo en el sexto día de edad adulta. Se obtuvo evidencia adicional de protección antioxidante al verificar el estado de oxidación de las proteínas con el kit de detección OxyBlot™. Los análisis por HPLC-DAD-ESI/MS confirmaron que los tres flavonoles fueron absorbidos por C. elegans, lo que dio lugar a la formación de algunos metabolitos glicosilados, sulfatados y metilados, y que estos últimos también se desmetilaron a quercetina. La cuantificación de los niveles de quercetina, isorhamnetina y tamarixetina, así como de sus metabolitos detectados, indicó una mayor absorción de quercetina por el nematodo que de sus derivados metilados. 2011-01-01T00:00:00Z http://hdl.handle.net/10366/165795 [EN] This study investigates the protective effect of the Sveva strawberry polyphenol-rich extract on human dermal fibroblasts against AAPH-induced oxidative stress. The HPLC-DAD/ESI-MS analysis was used for evaluating the phenolic composition of the fruits. Sveva strawberry presented a high anthocyanin content (639.79 mg per kg fresh fruit), representing 86.08% of the total phenolic content, with Pg-3-glc as the most abundant representative (611.18 mg per kg fresh fruit). Only one ellagitannin (agrimoniin) was identified, while two quercetins, three kaempherol derivates, and three ellagic acid derivatives were detected and quantified. Strawberry pre-treatment (0.5 mg/mL) markedly increased human dermal fibroblast viability, with a significant reduction of apoptotic and dead cells, and suppressed AAPH-induced ROS generation, after only 30 minutes of incubation with the oxidizing agent, and lipid peroxidation, against a range of AAPH concentrations tested. Notably, the strawberry extract also improved the mitochondrial functionality: the basal respiratory performance after treatment was 1.59-fold higher compared to control cells, while pre-treatment with strawberry extract before oxidative damage increased 2.70-fold compared to stressed cells. Our results confirm that the strawberry possesses antioxidant properties, and may be useful for the prevention of free radical-induced skin damage.; [ES] Este estudio investiga el efecto protector del extracto de fresa Sveva, rico en polifenoles, sobre fibroblastos dérmicos humanos contra el estrés oxidativo inducido por AAPH. Se utilizó el análisis HPLC-DAD/ESI-MS para evaluar la composición fenólica de las frutas. La fresa Sveva presentó un alto contenido de antocianinas (639,79 mg por kg de fruta fresca), lo que representa aproximadamente el 86,08 % del contenido fenólico total, siendo Pg-3-glc el más abundante (611,18 mg por kg de fruta fresca). Solo se identificó un elagitanino (agrimoniina), mientras que se detectaron y cuantificaron dos quercetinas, tres derivados de kaempferol y tres derivados de ácido elágico. El pretratamiento con fresa (0,5 mg ml⁻¹) aumentó notablemente la viabilidad de los fibroblastos dérmicos humanos, con una reducción significativa de las células apoptóticas y muertas, y suprimió la generación de ROS inducida por AAPH, tras tan solo 30 minutos de incubación con el agente oxidante, así como la peroxidación lipídica, frente a un rango de concentraciones de AAPH analizadas. Cabe destacar que el extracto de fresa también mejoró la funcionalidad mitocondrial: el rendimiento respiratorio basal tras el tratamiento fue aproximadamente 1,59 veces superior al de las células control, mientras que el pretratamiento con extracto de fresa antes del daño oxidativo aumentó aproximadamente 2,70 veces en comparación con las células estresadas. Nuestros resultados confirman que la fresa posee propiedades antioxidantes y podría ser útil para la prevención del daño cutáneo inducido por radicales libres. 2014-01-01T00:00:00Z http://hdl.handle.net/10366/165782 The aim of the present work was to analyze the phenolic extracts from two monofloral Cuban honeys for their in vitro total antioxidant capacity, phenolic compounds content and free radical scavenging activity. The phenolic extracts, rich in lipophilic compounds, were tested further for their ability to inhibit AAPH-induced oxidative damage (hemolysis, lipid peroxidation and cytosolic depletion of reduced glutathione and decrease of superoxide dismutase activity) in erythrocytes. Results indicate an important total antioxidant capacity measured by TEAC and ORAC assays, as well as a relevant radical scavenging activity performed by EPR. Moreover, 13 phenolic compounds were identified using HPLC–LC/MS with quercetin as the most abundant flavonoid. The results also show that both extracts were able to inhibit erythrocytes oxidative damage, and that this may likely be due to their incorporation into cell membranes and their ability to cross it and reach the cytosol. In fact, flavonoid uptake by erythrocytes was further confirmed by testing quercetin, which efficiently incorporated into erythrocytes. Overall, this study indicates that honey contains relevant antioxidant compounds responsible, at least in part, for its biological activity and that uptake of its flavonoids may provide defense and promote cell functions in erythrocytes. 2012-01-01T00:00:00Z http://hdl.handle.net/10366/165073 [EN] Strawberries are an important fruit in the Mediterranean diet because of their high content of essential nutrients and beneficial phytochemicals, which seem to exert beneficial effects in human health. Healthy volunteers were supplemented daily with 500 g of strawberries for 1 month. Plasma lipid profile, circulating and cellular markers of antioxidant status, oxidative stress and platelet function were evaluated at baseline, after 30 days of strawberry consumption and 15 days after the end of the study. A high concentration of vitamin C and anthocyanins was found in the fruits. Strawberry consumption beneficially influenced the lipid profile by significantly reducing total cholesterol, low-density lipoprotein cholesterol and triglycerides levels (−8.78%, −13.72% and −20.80%, respectively; P<.05) compared with baseline period, while high-density lipoprotein cholesterol remained unchanged. Strawberry supplementation also significant decreased serum malondialdehyde, urinary 8-OHdG and isoprostanes levels (−31.40%, −29.67%, −27.90%, respectively; P<.05). All the parameters returned to baseline values after the washout period. A significant increase in plasma total antioxidant capacity measured by both ferric reducing ability of plasma and oxygen radical absorbance capacity assays and vitamin C levels (+24.97%, +41.18%, +41.36%, respectively; P<.05) was observed after strawberry consumption. Moreover, the spontaneous and oxidative hemolysis were significant reduced (−31.7% and −39.03%, respectively; P<.05), compared to the baseline point, which remained stable after the washout period. Finally, strawberry intake significant decrease (P<.05) the number of activated platelets, compared to both baseline and washout values. Strawberries consumption improves plasma lipids profile, biomarkers of antioxidant status, antihemolytic defenses and platelet function in healthy subjects, encouraging further evaluation on a population with higher cardiovascular disease risk.; [ES]Las fresas son una fruta importante en la dieta mediterránea debido a su alto contenido de nutrientes esenciales y fitoquímicos beneficiosos , que parecen ejercer efectos beneficiosos en la salud humana. Voluntarios sanos fueron suplementados diariamente con 500 g de fresas durante 1 mes. El perfil lipídico plasmático , los marcadores circulantes y celulares del estado antioxidante, el estrés oxidativo y la función plaquetaria se evaluaron al inicio, después de 30 días de consumo de fresas y 15 días después del final del estudio. Se encontró una alta concentración de vitamina C y antocianinas en las frutas. El consumo de fresas influyó beneficiosamente en el perfil lipídico al reducir significativamente los niveles de colesterol total, colesterol de lipoproteínas de baja densidad y triglicéridos (−8,78%, −13,72% y −20,80%, respectivamente; P < ,05) en comparación con el período inicial, mientras que el colesterol de lipoproteínas de alta densidad se mantuvo sin cambios. La suplementación con fresas también disminuyó significativamente los niveles séricos de malondialdehído , 8-OHdG urinario e isoprostanos (−31,40%, −29,67%, −27,90%, respectivamente; P < ,05). Todos los parámetros volvieron a los valores basales después del período de lavado. Se observó un aumento significativo en la capacidad antioxidante total del plasma medida tanto por la capacidad reductora férrica del plasma como por los ensayos de capacidad de absorción de radicales de oxígeno y los niveles de vitamina C (+ 24,97%, + 41,18%, + 41,36%, respectivamente; P < ,05) después del consumo de fresas. Además, la hemólisis espontánea y oxidativa se redujeron significativamente (−31,7% y −39,03%, respectivamente;P< ,05), en comparación con el punto basal, que permaneció estable después del período de lavado. Finalmente, la ingesta de fresas disminuyó significativamente (P< ,05) el número de plaquetas activadas, en comparación con los valores basales y de lavado. El consumo de fresas mejora el perfil lipídico plasmático, los biomarcadores del estado antioxidante, las defensas antihemolíticas y la función plaquetaria en sujetos sanos, lo que fomenta una mayor evaluación en una población con mayor riesgo de enfermedad cardiovascular. 2014-01-01T00:00:00Z http://hdl.handle.net/10366/161886 Numerous residues, such as the coffee pulp, are generated throughout coffee processing. This by-product is a source of antioxidant phytochemicals, including phenolic compounds and caffeine. However, the antioxidant properties of the phenolic compounds from the coffee pulp are physiologically limited to their bioaccessibility, bioavailability, and biotransformation occurring during gastrointestinal digestion. Hence, this study explored the phenolic and caffeine profile in the coffee pulp flour (CPF) and extract (CPE), their intestinal bioaccessibility through in vitro digestion, and their potential bioavailability and colonic metabolism using in silico models. The CPE exhibited a higher concentration of phenolic compounds than the CPF, mainly phenolic acids (protocatechuic, chlorogenic, and gallic acids), followed by flavonoids, particularly quercetin derivatives. Caffeine was found in higher concentrations than phenolic compounds. The antioxidant capacity was increased throughout the digestive process. The coffee pulp matrix influenced phytochemicals’ behavior during gastrointestinal digestion. Whereas individual phenolic compounds generally decreased during digestion, caffeine remained stable. Then, phenolic acids and caffeine were highly bioaccessible, while flavonoids were mainly degraded. As a result, caffeine and protocatechuic acid were the main compounds absorbed in the intestine after digestion. Non-absorbed phenolic compounds might undergo colonic biotransformation yielding small and potentially more adsorbable phenolic metabolites. These results contribute to establishing the coffee pulp as an antioxidant food ingredient since it contains bioaccessible and potentially bioavailable phytochemicals with potential healthpromoting properties. 2022-01-01T00:00:00Z http://hdl.handle.net/10366/161885 Melatonin is a multifunctional antioxidant neurohormone found in plant foods such as lentil sprouts. We aim to evaluate the e ect of lentil sprout intake on the plasmatic levels of melatonin and metabolically related compounds (plasmatic serotonin and urinary 6-sulfatoxymelatonin), total phenolic compounds, and plasmatic antioxidant status, and compare it with synthetic melatonin. The germination of lentils increases the content of melatonin. However, the phenolic content diminished due to the loss of phenolic acids and flavan-3-ols. The flavonol content remained unaltered, being the main phenolic family in lentil sprouts, primarily composed of kaempferol glycosides. Sprague Dawley rats were used to investigate the pharmacokinetic profile of melatonin after oral administration of a lentil sprout extract and to evaluate plasma and urine melatonin and related biomarkers and antioxidant capacity. Melatonin showed maximum concentration (45.4 pg/mL) 90 min after lentil sprout administration. The plasmatic melatonin levels increased after lentil sprout intake (70%, p < 0.05) with respect to the control, 1.2-fold more than after synthetic melatonin ingestion. These increments correlated with urinary 6-sulfatoxymelatonin content (p < 0.05), a key biomarker of plasmatic melatonin. Nonetheless, the phenolic compound content did not exhibit any significant variation. Plasmatic antioxidant status increased in the antioxidant capacity upon both lentil sprout and synthetic melatonin administration. For the first time, we investigated the bioavailability of melatonin from lentil sprouts and its role in plasmatic antioxidant status. We concluded that their intake could increase melatonin plasmatic concentration and attenuate plasmatic oxidative stress. 2020-01-01T00:00:00Z http://hdl.handle.net/10366/161882 In this study, we have evaluated by HPLC-DAD, DLS and MALDI-TOF a synergic effect of the coexistence of two salivary-PRP fractions (basic-PRPs and acidic PRPs) on the interaction with flavanols. Results obtained showed noticeable enhancement of the interaction between (epi)catechin and PRPs when both types of proteins are blended. Up to 30 soluble aggregates have been tentatively identified with molecular weight from 4680 to 35,851. (epi)Catechins seem to bind preferentially bPRPs than aPRPs, although the medium size aggregates flavanol-bPRPs formed could favour the interaction with aPRPs giving rise to soluble mixed aggregates. 2019-01-01T00:00:00Z http://hdl.handle.net/10366/161881 In this work, the phenolic compounds of four Andean tubers grown in Ecuador, such as yacon (Smallantus sonchifolius), mashua (Tropaeolum tuberosum), melloco (Ullucus tuberosus) and purple-sweet potato (Ipomea batatas) were analyzed by HPLC–DAD–ESI/MSn. Non-flavonoid compounds, such as hydroxycinnamic derivatives were identified in yacon, purple sweet potato and melloco samples, accounting for 100, 26 and 15% of the total of phenolic compounds, respectively. Mashua sample revealed the presence of flavan-3-ol monomers that were not found in the other samples, being (-)-epicatechin the most abundant (9.22 μg/g DM). Quercetin-3-O-rutinoside (40.6 μg/g DM), kaempferol-O-dirhamnosil-hexoside (29.5 μg/g DM) and kaempferol-O-dihexoside (46.22 μg/g DM) were the main flavonols present in mashua, melloco and purple sweet potato, respectively, being this last specie which presented the highest concentration in flavonols (89.32 μg/g DM). Purple sweet potato also had anthocyanins (157.16 μg/g DM), not detected in the other samples. The presence of these compounds and the consideration of the total phenolic content suggest the use of these Andean tubers as promising sources of natural antioxidants of wide use in the food industry. Therefore, these tubers could be considered as novel and inexpensive sources of bioactive compounds for their potential use in functional foods and nutraceuticals. 2019-01-01T00:00:00Z http://hdl.handle.net/10366/161879 Teff is currently being incorporated into a range of foodstuffs, especially gluten-free flakes and extruded products. The main objective of this work was to assess the effects of different treatments (industrial milling, formation of flakes and extrusion) on the phenolic composition of two types of teff grains differing in their colour (white and brown). Fifty-nine phenolic compounds were detected by HPLC-DAD-MSn. C-glycosyl flavones accounted for more than 90% of the total phenolic contents in both teff types. White teff mostly contained apigenin- derived flavones (86–92%), whereas luteolin derivatives prevailed in brown teff (91–94%). The industrial processes, mainly flaking and extrusion, caused marked changes in the phenolic composition, some of which were dependent on the teff type. In both teff types, processing changed the phenolic profiles similarly by increasing C-monoglycosyl flavones and decreasing acylated derivatives. However, the total content was increased in flakes and extruded products made only from brown teff grains. 2021-01-01T00:00:00Z http://hdl.handle.net/10366/161878 The objective of this study was to assess how in vitro gastrointestinal digestion influenced the bioaccessibility and potential bioavailability of phenolic compounds and methylxanthines in the cocoa shell (CS) in the form of flour (CSF) and aqueous extract (CSE). To comprehend how these phytochemicals behaved during gastrointestinal digestion, we also modeled in silico the colonic microbial biotransformation of the phenolic compounds in the CS. Different groups of phenolic compounds (mainly gallic and protocatechuic acids, and catechin) and methylxanthines (theobromine and caffeine) could be found in the CS. Methylxanthines and phenolic compounds were released differently during gastrointestinal digestion. Whereas digestion triggered the release of hydroxybenzoic acids (67–73%) and flavan-3-ols (73–88%) during the intestinal phase, it also caused the degradation of flavonols and flavones. Besides, the release of phytochemicals was significantly influenced by the CS matrix type. Phenolic compounds were protected by the CSF matrix. Phenolic acids from CSF were more bioaccessible in the intestinal (1.2-fold, p < 0.05) and colonic (1.3-fold, p < 0.05) phases than those from the CSE. Methylxanthines were also more bioaccessible in the intestinal (1.8-fold, p < 0.01) and colonic phases (1.3-fold, p < 0.001) and bioavailable (1.8-fold, p < 0.001) in the CSF. Colonic metabolism demonstrated that the gut microbiota could biotransform non-absorbed phenolic compounds into other lower molecular weight and more bioavailable metabolites. These findings support the CS’s potential as a source of bioaccessible, bioavailable, and active phytochemicals. 2022-01-01T00:00:00Z http://hdl.handle.net/10366/161853 [EN] The disappearance of the C-glycosidic ellagitannins over time can occur even in absence of oxygen and their disappearance rate seems to be affected by the presence of other ellagitannins in the media. The objective of this work was to study the influence of the presence of other ellagitannins and/or oxygen on the individual evolution of the main oak ellagitannins in simple model systems in order to understand their behaviours in more complex media, such as wine. In all the studied conditions, vescalagin disappeared faster than castalagin, highlighting its greater reactivity. Oxygen increased the individual disappearance rate, as also occurred when more than one type of ellagitannin was present, above all if the additional ellagitannin(s) contained the same conformation in C1 as vescalagin. Experimental data were fitted to a kinetic model considering both the oxygen-dependent and oxygen-independent reactions, making possible the comparison between individual compounds in different scenarios. 2019-07-01T00:00:00Z http://hdl.handle.net/10366/161803 [EN] One of the main consequences of the advancement of harvest date associated to global climate change is that the phenolic maturity of grapes can be delayed in relation to their technological maturity. As a consequence, wines made from these grapes can be poor in phenolic compounds or possess an unbalanced phenolic composition, affecting their global quality. The combined post-fermentative addition of seeds and an astringency-modulator mannoprotein (MP) might be a potential strategy to solve this problem, since seeds might supply flavanols and improve wine chemical stability and the mannoprotein might modulate the changes induced in astringency by the addition of seeds and improve wine colloidal stability. The present study aimed at monitoring at different moments of winemaking and ageing the effects and side-effects of this combined strategy on the detailed flavanol, flavonol and anthocyanin compositions and on colour of wines made from Syrah grapes. Seeds were obtained from Pedro Ximénez overripe grapes. Flavanol composition and flavonol and anthocyanin compositions were determined by HPLC-MSn-MRM and HPLC-DAD-MSn analyses, respectively. Colour changes caused by these additions were studied from CIELAB parameters as well as the ability of these techniques to protect colour from bleaching agents, such as SO2. In general, the addition of seeds initially increased the levels of flavanols and anthocyanins. However, during bottle ageing a reduction in the levels of flavanols, flavonols and anthocyanins could be observed in seed treated wines, which might be related to the greater formation of flavanol aggregates associated with greater levels of flavanols. This effect was partially solved for most of the flavonoids studied with the additional MP treatment. Treated and control wines showed colour differences that were visible to human eye, although they were reduced over time. At the end of the study, treated wines showed colour parameters corresponding to younger wines than those observed in control wines. A greater resistance against SO2 bleaching was also observed in treated wines, which can be mainly associated to the greater percentages of polymeric pigments caused by seed treatment and to the improvement of the colloidal stability of SO2-resistant pigments caused by the addition of the MP. 2019-12-01T00:00:00Z