Search results for "Tannin"
showing 10 items of 66 documents
In vitro bioactive properties of phlorotannins recovered from hydrothermal treatment of Sargassum muticum
2016
Abstract The present work addresses the potential of different adsorbents for the recovery of the phlorotannin fraction present in the liquid phase from the autohydrolysis of Sargassum muticum. Operating with the extract generated during autohydrolysis of alginate exhausted algae, the kinetics followed pseudo-second order and the equilibrium corresponded to Freundlich model. In batch configuration, up to 70% phlorotannins were adsorbed and up to 30% were desorbed with ethanolic solutions. Comparable performance was observed with the autohydrolysis extracts from the whole algae. The phloroglucinol content, the reducing and ABTS antiradical capacities of the desorbed product increased by 2–4 …
Sicilian Myrtle Diversity: Evaluation of Leaf Total Phenols Content and Antioxidant Properties
2017
Myrtle (Myrtus communis L.) is an aromatic plant spontaneously growing and increasingly cultivated in Mediterranean area. Recently, interest on myrtle plant is growing due to the pharmacological and antioxidant properties since myrtle leaves are important sources of phenolic and antioxidant compounds with health-promoting effects. Plant genotype is the primary factor affecting antioxidant activity and phenol content. For this reason, a core collection of local selected myrtle accessions from Sicily was evaluated with the aim to identify genotypes with high antioxidant value. Thirty-six myrtle individuals belonging to seven populations were studied for leaf total phenols, tannins and antioxi…
Defoliation of two-wire vertical trellis: effect on grape quality
2017
ABSTRACTBasal leaves were removed from Cabernet Sauvignon vines trained to a two-wire vertical trellis at fruit set and at veraison. Leaf removal did not modify total soluble solids and titratable acidity at harvest. Defoliation at fruit set of lower cordon recovered the grape anthocyanin composition gap between upper and lower cordons and that produced a positive effect on anthocyanin synthesis. Hence, control of the upper cordon and defoliation of fruit set of the lower cordon treatments showed comparable values of anthocyanins. Defoliation at veraison did not produce any appreciable effect. This study shows that skin anthocyanin composition in a two-wire vertical trellis can be modified …
Effect of Sunlight Exposure on Anthocyanin and Non-Anthocyanin Phenolic Levels in Pomegranate Juices by High Resolution Mass Spectrometry Approach
2020
Quali-quantitative analyses of anthocyanins and non-anthocyanin phenolic compounds performed with the use of liquid chromatography coupled with high resolution mass spectrometry, were evaluated in juice of pomegranate fruits (&lsquo
Influence of pre-fermentative addition of aqueous solution tannins extracted from oak wood (Quercus petraea) on the composition of Grillo wines
2021
AbstractIn this research, the chemical characterization of fixed and volatile compounds of two different tannins in aqueous solution (Pratiko® L-Harvest and L-Fruit) extracted from oak wood, has been studied. The influence of the above tannins, at different concentrations, on the alcoholic fermentation kinetics and on the composition and sensorial characteristics of a white wine were then evaluated. The wines added tannins in aqueous solution compared to control wines showed significant differences in fixed compounds (colloids, polyphenols and ellagitannins) and volatile compounds (phenolic aldehydes, volatile phenols, furanic and piranic compounds). The differences of aqueous solution tann…
How to Deal with Uninvited Guests in Wine: Copper and Copper-containing Oxidases
2020
Copper is one of the most frequently occurring heavy metals in must and wine. It is introduced by pesticides, brass fittings, and as copper sulphate for treatment of reductive off-flavors. At higher concentrations, copper has harmful effects on the wine. It contributes to the oxidation of wine ingredients, browning reactions, cloudiness, inhibition of microorganisms, and wine fermentation. Last but not least, there is also a danger to the consumer. At present, some physicochemical methods exist to reduce the copper content in must and wine, but they all have their shortcomings. A possible solution is the biosorption of metals by yeasts or lactobacilli. Copper can also reach must and wine in…
Impact of Oak Wood Barrel Tannin Potential and Toasting on White Wine Antioxidant Stability
2019
International audience; Wines aged in oak wood barrels with various uniform tannin contents (which were classified according to their total ellagitannins contents as predicted by Near Infrared Spectroscopy on the untoasted wood) and different toasting levels (high precision toasting by radiation) were distinguished according to their overall abilities to resist against oxidation. Wine trials were carried out on two different vintages (2015, 2016) and three grape varieties (Sauvignon blanc, Sémillon, Chardonnay). Regardless of the vintage and the wine matrix, a relationship was established between wine oxidative stability (based on EPR spin trapping methodology) and oak barrel tannin potenti…
From Norway Spruce Bark to Carbon Foams : Characterization, and Applications
2020
Fresh bark from spruce Picea abies was milled and extracted with hot water. The extracts were purified in a number of steps in order to get tannin-extracts pure enough to prepare tannin-based carbon foams. The chemical composition of the extracts were analyzed. The foams were maturated and thermally treated to obtain desired properties, such as specific surface area, porosity, and compressive strength. It was possible to produce carbon foams even if they contained carbohydrate impurities. Differences in the properties of the carbon foams such as compressive strength, specific surface areas, and pore size distributions might be related to the compositions of the extracts. The foams were fina…
Plant polyphenols, chemoreception, taste receptors and taste management
2019
International audience; Purpose of review Polyphenols display beneficial health effects through chemopreventive actions on numerous chronic diseases including cancers, metabolic disorders, reproductive disorders and eating behaviour disorders. According to the principle of chemoreception, polyphenols bind cellular targets capable of accepting their stereochemistry, namely metabolizing enzymes and protein receptors, including taste receptors. The extraoral expression of taste receptors and their pharmacological interest in terms of novel drug therapies open up new perspectives on the potential use of these compounds and their interactions with other chemicals in cells. These new perspectives…
Ellagitannin-rich cloudberry inhibits hepatocyte growth factorinduced cell migration and phosphatidylinositol 3-kinase/AKT activation in colon carcin…
2016
// Anne-Maria Pajari 1, 2 , Essi Paivarinta 1 , Lassi Paavolainen 3 , Elina Vaara 1 , Tuuli Koivumaki 4 , Ritu Garg 5 , Anu Heiman-Lindh 1 , Marja Mutanen 1 , Varpu Marjomaki 3 , Anne J. Ridley 2, 5 1 Department of Food and Environmental Sciences, Division of Nutrition, University of Helsinki, Helsinki, Finland 2 University College London, Ludwig Institute for Cancer Research, London, UK 3 Department of Biological and Environmental Science / Nanoscience Center, University of Jyvaskyla, Jyvaskyla, Finland 4 Department of Food and Environmental Sciences, Division of Food Chemistry, University of Helsinki, Helsinki, Finland 5 Randall Division of Cell & Molecular Biophysics, King’s College Lond…