Search results for "Polyphenols"
showing 10 items of 293 documents
Chromatographic Profiles of the main Secondary Metabolites in the Monarda fistulosa L. Aerial Part
2021
Two different methods of chromatographic analysis have been used in this study for the phytochemical evaluation of main secondary metabolites in the aerial part of bee balm (Monarda fistulosa L.) as the non-officinal medicinal plant of the Lamiaceae Martinov family. The high performance thin layer chromatography (HPTLC) fingerprinting method was developed for the qualitative analyses of phenolic and non-polar compounds in the bee balm herb after its maceration in the solvents of different polarity. Such polyphenols as rosmarinic, caffeic and chlorogenic acids were authentically identified in the methanol extract of herb using HPTLC. Aromatic monoterpenoid thymol was identified by the HPTLC …
COMPARISON BETWEEN TWO TYPES OF WINEMAKING TANKS FOR THE PRODUCTION OF QUALITY WINES CV. NERO D’AVOLA
2012
The aim of this work is to compare two types of winemaking tanks, horizontal and vertical, using Nero d’Avola grapes, in order to assess the capacity of extraction of phenolic compounds that determine the quality of red wines. The study shows that in wine made by horizontal winemaking tanks, both anthocyanins and polyphenols have a higher decrease in time compared to wine made by the vertical type. The higher values of polyphenols found in the horizontal type appear to show that wines produced by this type of winemaking tank have a better quality in terms of health for antimicrobial, antioxidant and antiinflammatory properties of these molecules.
The influence of two different pH levels on the antioxidant properties of flavonols, flavan-3-ols, phenolic acids and aldehyde compounds analysed in …
2011
Abstract The aim of this study is evaluate either the antioxidant or pro-oxidant behaviour of some typical polyphenolic compounds of red wine, to investigate the influence of two different pH levels on the antioxidant properties and to clarify their activity–structure relationship. The antioxidant activity of compounds in hydrophilic solutions at pH 3.5 and pH 7.4 were measured by a competition kinetic test, based on the crocin bleaching. The position and the number of substitution groups influence the magnitude of the antioxidant activity of the polyphenolic compounds, but their antioxidant properties are also strongly influenced by the pH conditions. Increasing the pH, a considerable incr…
Effects of postharvest partial dehydration and prolonged treatments with ethylene on transcript profiling in skins of wine grape berries.
2010
For certain food products, postharvest controlled stresses or treatments with specific elicitors are applied to induce desired physical/chemical changes and/or to positively affect phytochemical content. This is the case of wine grapes where both strategies, singularly applied or coupled, can be used to modulate berry composition and, as a consequence, affect wine quality traits. Since the knowledge of the effects of these postharvest treatments on berry metabolism and the regulation of gene expression is very limited, a large-scale transcriptome analysis has been carried out, using an oligo-based microarray (14,562 probes) on skins of wine grape (Vitis vinifera L.) berries subjected to deh…
Carob leaves polyphenols trigger intrinsic apoptosis pathway and induce cell cycle arrest in colon cancer cells
2016
IF 4.066; International audience
Influence of Temperature, Solvent and pH on the Selective Extraction of Phenolic Compounds from Tiger Nuts by-Products: Triple-TOF-LC-MS-MS Character…
2019
The aim of this study was to assess the effect of temperature, solvent (hydroethanolic mixtures) and pH on the recovery of individual phenolic compounds from &ldquo
Green and Quick Extraction of Stable Biophenol-Rich Red Extracts from Grape Processing Waste
2021
The extraction of grape processing waste (wine pomace) via microwave-hydrodiffusion and gravity (MHG) from three different cultivars grown in Sicily (Syrah, Perricone and Nero d’Avola) rapidly affords aqueous extracts highly concentrated in valued biophenols including flavonoids, anthocyanins and phenolic acids. The method does not employ organic solvent, acid or base and does not require grinding or freeze drying of the wine pomace nor separation of the grape skins from seeds and stem. All the extracts have a pronounced stability as shown by their red-violet color fully retained after storage for more than a year (15 months) in freezer under air. Concentrations of phenolics up to…
Behaviour of some compounds with lmax at 280 nm in determination of total flavonoids of grape skin extracts made from a hydroalcoholic SO2-rich solve…
2010
This paper reports the results of a study on the ambiguous behaviour of substances with lmax at 280 nm in the determination of total flavonoids in whole grape skin extracts made from a hydroalcoholic SO2-rich solvent, apparently not eluted with methanol after absorption on a C18 cartridge employed for sample pre-concentration and SO2 removal. After rejecting the hypothesis that they were irreversibly absorbed on the C18 cartridge, it seemed that they reacted with other phenolics during passage through the C18 cartridge and were totally eluted with methanol in this new combined form. This new hypothesis seems very probable and is in accord with the more recent acquisition about the synthesis…
Effect of different processing methods on the quality of obtained pomegranate juice
2019
Pomegranate juice has many health properties as the fruits contain anticarcinogenic, antimicrobial and antiviral compounds. Its consumption has greatly increased throughout the world in recent years due to the potential of its different components, polyphenols and anthocyanins mostly. Many studies have been performed on the pomegranate juice yield demonstrating its influence on the organoleptic and physicochemical properties of the juice. Commercial pomegranate juice production involves pressing the fruits. As a consequence, there is a need to investigate the pressing machine types and adjustment in order to maximize juice yield and enhance its health properties. The aim of this study was t…
Species-Specific Antioxidant Power and Bioactive Properties of the Extracts Obtained from Wild Mediterranean Calendula Spp. (Asteraceae)
2019
In this study we focused on four taxa of the genus Calendula (C. maritima, C. suffruticosa subsp. fulgida, C. arvensis, and the hybrid between the first two ones), collected in Mediterranean area (Sicily). Six extracts for each species were obtained using solvents with increasing polarity (hexane, ethanol 80%, acetone 70%, and water) and through extraction by supercritical fluids (SFE). It has been observed that the solvent with the highest extraction efficiency was ethanol 80% for all species. However, SFE extracts showed high antioxidant activity comparable to the ethanol 80% extract (polyphenol, DPPH, and reducing power method). These findings were confirmed by in vitro analysis (MTT ass…