1,293 research outputs found
An Exogenous Pre-Storage Melatonin Alleviates Chilling Injury in Some Mango Fruit Cultivars, by Acting on the Enzymatic and Non-Enzymatic Antioxidant System
Melatonin (MT) treatment (100 M, 2 h) was applied to four mango fruit cultivars (‘Langra’,
‘Chaunsa’, ‘Dashehari’, and ‘Gulab Jamun’), before being stored at 5 1 C for 28 d, in order
to alleviate chilling injury (CI). Maximum CI reduction was observed in ‘Langra’ mangoes, and
minimum in ‘Gulab Jamun’ mangoes. This positive effect on quality preservation was associated with
an increased concentration of endogenous MT, which prevented the accumulation of reactive oxygen
species (H2O2 and O2
) and stimulated non-enzymatic antioxidants (total phenolic compounds
and total flavonoids), possibly due to higher activity of phenylalanine ammonia lyase and tyrosine
ammonia lyase. Increased antioxidant activity was also documented in MT-treated ‘Langra’ mangoes,
according to four different assays (DPPH, TEAC, FRAP, and CUPRAC) and higher activity of six
antioxidant enzymes (superoxide dismutase, catalase, peroxidase, ascorbate peroxidase, glutathione
reductase, and dehydroascorbate reductase). In contrast, ‘Gulab Jamun’ mangoes showed minimal
or no positive effects on the aforementioned variables in response to the exogenous MT application.
‘Chaunsa’ and ‘Dashehari’ mangoes had some intermediate effects on their antioxidant system
(enzymatic and non-enzymatic) and alleviation of CI, when treated with exogenous MT.We conclude
that exogenous MT exerts a cultivar-dependent stimulating effect on the antioxidant system of
mangoes, which results in an increase in the fruits’ resistance to low temperature
In vitro studies on the relationship between the antioxidant activities of some berry extracts and their binding properties to serum albumin
The aim of this study was to investigate the possibility to use the bioactive components from cape gooseberry (Physalis peruviana), blueberry (Vaccinium corymbosum), and cranberry (Vaccinium macrocarpon) extracts as a novel source against oxidation in food supplementation. The quantitative analysis of bioactive compounds (polyphenols, flavonoids, flavanols, carotenoids, and chlorophyll) was based on radical scavenging spectrophometric assays and mass spectrometry. The total phenolic content was the highest (P < 0.05) in water extract of blueberries (46.6 ± 4.2 mg GAE/g DW). The highest antioxidant activities by 2,2-diphenyl-1-picrylhydrazyl radical scavenging assay and Cupric reducing antioxidant capacity were in water extracts of blueberries, showing 108.1 ± 7.2 and 131.1 ± 9.6 μMTE/g DW with correlation coefficients of 0.9918 and 0.9925, and by β-carotene linoleate assay at 80.1 ± 6.6 % with correlation coefficient of 0.9909, respectively. The water extracts of berries exhibited high binding properties with human serum albumin in comparison with quercetin. In conclusion, the bioactive compounds from a relatively new source of gooseberries in comparison with blueberries and cranberries have the potential as food supplementation for human health. The antioxidant and binding activities of berries depend on their bioactive compounds
The Extrusion Process as an Alternative for Improving the Biological Potential of Sorghum Bran: Phenolic Compounds and Antiradical and Anti-Inflammatory Capacity
Approximately 80% of sorghum phenolic compounds are linked to arabinoxylans by ester bonds, which are capable of resisting the digestion process in the upper gastrointestinal tract, compromising their bioaccessibility and biological potential. The aim of this study was to evaluate the effect of the extrusion process on the content of phenolic compounds in sorghum bran and its impact on phenolic compounds and antiradical and anti-inflammatory capacity. Results revealed that the extrusion process increased total phenol content in sorghum bran compared to nonextruded sorghum, particularly for extrusion at 180°C with 20% moisture content (2.0222±0.0157 versus 3.0729±0.0187 mg GAE/g +52%), which positively affected antiradical capacity measured by the DPPH and TEAC assays. The percentage of inhibition of nitric oxide (NO) production by RAW cells due to the presence of extruded sorghum bran extract was significantly higher than that of nonextruded sorghum bran extract (90.2±1.9% versus 76.2±1.3%). The results suggest that extruded sorghum bran could be used as a functional ingredient and provide advantages to consumers by reducing diseases related to oxidative stress and inflammation
In vitro Inhibition of Pancreatic Lipase by Polyphenols: A Kinetic, Fluorescence Spectroscopy and Molecular Docking Study
Svrha je ovog istraživanja bila ispitati molekulsko uklapanje i inhibicijski učinak četiri fenolna spoja pronađena u ljutim papričicama, i to: kavene kiseline, p-kumarne kiseline, kvercetina i kapsaicina, na aktivnost lipaze izolirane iz svinjske gušterače. Najjači inhibicijski učinak imao je kvercetin (IC50=(6.1±2.4) μM), zatim p-kumarna (170.2±20.6) μM) i kavena kiselina (401.5±32.1) μM), dok su kapsaicin i ekstrakt ljute papričice imali iznimno slab učinak. Svi polifenolni spojevi imali su inhibicijski učinak miješanog tipa. Mjerenjem fluorescencije utvrđeno je da su polifenolni spojevi ugasili prirođenu fluorescenciju lipaze izolirane iz gušterače, i to pomoću statičkog mehanizma. Sekvencija Stern-Volmerove konstante bila je: kvercetin, kavena kiselina, te p-kumarna kiselina. Rezultati ispitivanja molekulskih uklapanja pokazali su da se kavena kiselina, kvercetin i p-kumarna kiselina vežu blizu, za razliku od kapsaicina koji se veže daleko od aktivnog mjesta. Vodikove veze i hidrofobne pi-interakcije glavni su načini međusobnog povezivanja polifenolnih spojeva u lipazi izoliranoj iz gušterače.The inhibitory activity and binding characteristics of caffeic acid, p-coumaric acid, quercetin and capsaicin, four phenolic compounds found in hot pepper, against porcine pancreatic lipase activity were studied and compared to hot pepper extract. Quercetin was the strongest inhibitor (IC50=(6.1±2.4) μM), followed by p-coumaric acid ((170.2±20.6) μM) and caffeic acid ((401.5±32.1) μM), while capsaicin and a hot pepper extract had very low inhibitory activity. All polyphenolic compounds showed a mixed-type inhibition. Fluorescence spectroscopy studies showed that polyphenolic compounds had the ability to quench the intrinsic fluorescence of pancreatic lipase by a static mechanism. The sequence of Stern-Volmer constant was quercetin, followed by caffeic and p-coumaric acids. Molecular docking studies showed that caffeic acid, quercetin and p-coumaric acid bound near the active site, while capsaicin bound far away from the active site. Hydrogen bonds and π-stacking hydrophobic interactions are the main pancreatic lipase-polyphenolic compound interactions observed
Yield, Quality and Phytochemicals of Organic and Conventional Raspberry Cultivated in Chihuahua, Mexico
Raspberry production represents an alternative for farmers in the temperate zones of Mexico. Due to the environmental impact caused by conventional agriculture, there is currently greater demand for organic food in the national and international market. To achieve this need, new fertilization techniques based on organic amendments are being tested. In the present study, yields and quality were evaluated over a 3-year period (2015, 2016 and 2017) as well as the phytochemical compounds of the production in 2017, with management of organic versus conventional fertilization of raspberry crop in open field in Cuauhtémoc, Chihuahua, Mexico. During the three years of study, the conventional fertilization system obtained higher yields, compared to the organic one, with values of 2,698 and 2,351 g per linear meter in 2015, 2,423 and 1,301 g per linear meter in 2016 and the data for 2017 were 3,077 and 2,550 g per linear meter, respectively. Regarding quality, the results showed no statistical differences between the two systems of production about colour, firmness, total soluble solids, titratable acidity and pH of the fruit. Differently the composition of phytochemicals, phenols, flavonoids, total anthocyanins and antioxidant capacity was better under the organic management. In conclusion, the conventional system showed higher yields, the quality of the fruits was not different between the two systems, while the levels of phytochemicals were higher with the organic farming. Therefore, it is important to continue the research in order to improve soil fertility and achieve higher yields under the organic management
Antimicrobial and antioxidant properties of byproduct extracts of mango fruit
Byproducts of fruit processing could have higher content of phenolic compounds that can act as antimicrobial and antioxidant agents. In this context, the main objective of this study was to obtain extracts from peel, seed, and unused flesh of Haden, Ataulfo and Tommy Atkins mango varieties, in order to measure their antioxidant and antimicrobial properties. The extraction was performed using different methods, such as methanolic-polar, methanolic-non-polar, ethanolic-polar, ethanolic-non-polar and water infusion. The total phenolic content of the ethanolic-non-polar extract from seed of mango Haden showed 875.06 mg/g, DPPH EC50: 0.04 mg/mL, cau-sing a 100 % inhibition of bacteria pathogens applying 25 mg/mL and inhibition of 89.78 % against Alternaria applying 6.25 mg/mL. The flesh always showed the lowest content and bioactivity of the tested parameters. These results demonstrate the antimicrobial and antioxidant potential uses of fruit byproducts as sources of bioactive compounds
Antioxidant and Antimicrobial Capacity of Phenolic Compounds of Mango (Mangifera indica L.) Seed depending upon the Extraction Process
The extraction method is critical for the recovery of phenolic compounds. The main goal was to evaluate the effect of an extraction process from mango seed on their phenolic profile, antioxidant and antimicrobial capacities. Phenolic extraction was performed in different steps: maceration, alkaline hydrolysis, acid/alkaline hydrolysis, polar and non-polar fraction of an ethyl acetate separation.The macerated extract showed a higher variety of polyphenols from mango seed:gallic (138.36 µg/g dry weight), coumaric (65.36 µg/g), ferulic (1376.67 µg/g) , chlorogenic (57.75 µg/g) anddicaffeoylquinic (219.29 µg/g) acids, catechin (16.78 µg/g) and rutin (6678.62µg/g). In alkaline hydrolyzed extract most of these compounds were lost, ferulic acid decreased 1356.77 µg/g dw and gallic acid increased 1383.89 µg/g dw. Gallic and chlorogenic acids increased 165 and 969. 45 µg/g dw respectively in acid/alkaline hydrolyzed, 109.57 and 841.38 µg/g dw respectively in non-polar and 277.15 and 77.88 µg/g dw respectively in polar extracts related to the macerated extract. Rutin was found only in acid/hydrolyzed and non-polar extract in lesser amount (87.62 and 78.51 µg/g dw) compared to macerated extract. The content of phenolic compounds was higher for the macerated extract (phenols=484.42 mg GAE/g and flavonoids=86.59 mg QE/g) than for the other steps. Acid/alkaline hydrolysis increased the antioxidant activity (1787.67 μmol TE/g for DPPH and 3692.86 μmol TE/g for TEAC); while the alkaline hydrolysis increased the antimicrobial effectivity (MIC=2.5 mg/mL for bacteria and 0.5 mg/mL for yeast). Results indicate that the acid or alkaline hydrolysis yields a stronger antioxidant and antimicrobial extract
Leptonic CP Violation and Neutrino Mass Models
We discuss leptonic mixing and CP violation at low and high energies,
emphasizing possible connections between leptogenesis and CP violation at low
energies, in the context of lepton flavour models. Furthermore we analyse weak
basis invariants relevant for leptogenesis and for CP violation at low
energies. These invariants have the advantage of providing a simple test of the
CP properties of any lepton flavour model.Comment: 26 pages, no figures, submitted to the Focus Issue on `Neutrino
Physics` edited by F. Halzen, M. Lindner and A. Suzuki, to be published in
New Journal of Physic
La investigación biomédica en España (II). Evaluación del Fondo de Investigación Sanitaria (FIS) a través de los proyectos de investigación financiados en el período 1988-1995 a centros de investigación, facultades y escuelas
En un trabajo previo, publicado en esta misma revista, los autores han estudiado los resultados generados por los proyectos de investigación financiados por el Fondo de Investigación Sanitaria (FIS) a las Instituciones Sanitarias Asistenciales (hospitales) y los procedentes de los cuestionarios de encuestas remitidos a los investigadores responsables de tales proyectos y a los directores gerentes de los hospitales en los que se realizaron los mismos.
En el presente trabajo, se continúa el proceso de evaluación del FIS, centrándose la atención en la distribución de los proyectos de investigación concedidos a los centros de investigación, facultades y escuelas, y en los resultados obtenidos a través de los cuestionarios de encuesta cumplimentados por los investigadores principales pertenecientes a estas instituciones o entidades.La realización de este trabajo ha sido posible gracias a la financiación otorgada por el FIS al proyecto de investigación 96/1803.Peer reviewe
Search for coherent elastic neutrino-nucleus scattering at a nuclear reactor with CONNIE 2019 data
The Coherent Neutrino-Nucleus Interaction Experiment (CONNIE) is taking data
at the Angra 2 nuclear reactor with the aim of detecting the coherent elastic
scattering of reactor antineutrinos with silicon nuclei using charge-coupled
devices (CCDs). In 2019 the experiment operated with a hardware binning applied
to the readout stage, leading to lower levels of readout noise and improving
the detection threshold down to 50 eV. The results of the analysis of 2019 data
are reported here, corresponding to the detector array of 8 CCDs with a
fiducial mass of 36.2 g and a total exposure of 2.2 kg-days. The difference
between the reactor-on and reactor-off spectra shows no excess at low energies
and yields upper limits at 95% confidence level for the neutrino interaction
rates. In the lowest-energy range, 50-180 eV, the expected limit stands at 34
(39) times the standard model prediction, while the observed limit is 66 (75)
times the standard model prediction with Sarkis (Chavarria) quenching factors.Comment: 23 pages, 14 figure
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