Search results for "Polyphenol"

Ultrasound-Assisted Extraction, Centrifugation and Ultrafiltration: Multistage Process for Polyphenol Recovery from Purple Sweet Potatoes

2016

This work provides an evaluation of an ultrasound-assisted, combined extraction, centrifugation and ultrafiltration process for the optimal recovery of polyphenols. A purple sweet potato (PSP) extract has been obtained using ultrasonic circulating extraction equipment at a power of 840 W, a frequency of 59 kHz and using water as solvent. Extract ultrafiltration, using polyethersulfone (PES), was carried out for the recovery of polyphenol, protein and anthocyanin. Pre-treatment, via the centrifugation of purple sweet potato extract at 2500 rpm over 6 min, led to better polyphenol recovery, with satisfactory protein removal (reused for future purposes), than PSP extract filtration without cen…

The antioxidant capacity of red wine in relationship with its polyphenolic constituents

2008

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 increase in a…

Inhibition of Folic Acid Uptake by Catechins and Tea Extracts in Caco-2 Cells

2006

In this present study it was aimed to determine whether the catechins contained in green tea and the whole extracts of Camellia sinensis (Theaceae) inhibit the uptake of folic acid by Caco-2 cell monolayers. Our results indicate that (-)-epigallocatechin 3-gallate (EGCG) and (-)-epicatechin 3-gallate (ECG) inhibit cellular folic acid uptake with IC50 values of 34.8 micromol/L and 30.8 micromol/L, respectively. Furthermore, green and black tea extracts were also found to inhibit folic acid uptake with IC50 values of approximately 7.5 and 3.6 mg/mL, respectively. According to these results, simultaneous intake of tea and folic acid may inhibit intestinal folic acid absorption. The consequence…

Influence of storage and in vitro gastrointestinal digestion on totqal antioxidant capacity of fruit beverages

2011

Eight fruit beverages containing grape, orange and apricot, with/without iron and/or zinc and with/without milk added were analyzed for total antioxidant capacity (ORAC and TEAC methods), ascorbic acid content, and total polyphenols. The influence of cold storage (2-4 degrees C) during the product shelf-life (135 days) and antioxidant capacity after an in vitro gastrointestinal digestion were evaluated. Antioxidant capacity for all beverages together increased significantly (p < 0.05) at the end of storage (16.4% and 12.8% for ORAC and TEAC, respectively), whereas ascorbic acid remained stable. Regarding in vitro digestion, antioxidant values of bioaccessible fractions of fruit beverages in…

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 …

Bioreactivity of Resveratrol Toward Inflammation Processes

2014

Grape polyphenols are abundant. They play essential roles in the vine’s life, particularly in its defense mechanisms. Interestingly, the grape, fresh or dried, is a widely consumed fruit by humans, as are its processed products, grape juice and wine. Moreover, they contain vast and highly varied quantities of polyphenols. Like other phytophenols, grape and wine resveratrol is considered a protective micronutrient like flavonoids, epicatechins in green tea and cocoa, quercetin in apples and onions, curcumin of the turmeric root, and hydroxytyrosol in olive oil. Resveratrol is a powerful natural antioxidant in vine. Interestingly, in humans, it protects low density lipoproteins against oxidat…

High Performance Liquid Chromatography Analysis of Grape and Wine Polyphenols

2008

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.

Polyphenol Oxidases from Wine Grapes

2017

Wine is produced from grapes which contain enzymes forming unfavorable dark polymers such as melanin, oxidizing proteins, and phenols which may influence their functions. Here we focus on the class of type-3 copper proteins presenting new insights on the structure, the occurrence during the ripening process and during wine making. Then, the reactivity of the enzymes on polyphenols from wine grapes are discussed and the possible consequences on health.

The phenolic compounds of olive oil: structure, biological activity and beneficial effects on human health

2005

AbstractThe Mediterranean diet is rich in vegetables, cereals, fruit, fish, milk, wine and olive oil and has salutary biological functions. Epidemiological studies have shown a lower incidence of atherosclerosis, cardiovascular diseases and certain kinds of cancer in the Mediterranean area. Olive oil is the main source of fat, and the Mediterranean diet's healthy effects can in particular be attributed not only to the high relationship between unsaturated and saturated fatty acids in olive oil but also to the antioxidant property of its phenolic compounds. The main phenolic compounds, hydroxytyrosol and oleuropein, which give extra-virgin olive oil its bitter, pungent taste, have powerful a…