Helene FULCRAND - Academia.edu (original) (raw)

Papers by Helene FULCRAND

HAL (Le Centre pour la Communication Scientifique Directe), 2023

HAL is a multidisciplinary open access archive for the deposit and dissemination of scientific re... more HAL is a multidisciplinary open access archive for the deposit and dissemination of scientific research documents, whether they are published or not. The documents may come from teaching and research institutions in France or abroad, or from public or private research centers. L'archive ouverte pluridisciplinaire HAL, est destinée au dépôt et à la diffusion de documents scientifiques de niveau recherche, publiés ou non, émanant des établissements d'enseignement et de recherche français ou étrangers, des laboratoires publics ou privés.

Neuroscience Letters, 1992

The effects of the endopeptidase 24.11 ('enkephalinase') inhibitor thiorphan, the... more The effects of the endopeptidase 24.11 ('enkephalinase') inhibitor thiorphan, the aminopeptidase inhibitor bestatin and a novel metallopeptidase inhibitor JMV 390-1 on the K(+)-evoked release of immunoreactive neurotensin and neuromedin N (iNT and iNN) from mouse hypothalamic slices were examined. (JMV 390-1 inhibits several metallopeptidases including endopeptidases 24.11, 24.15 and 24.16, and aminopeptidase N equipotently with Ki values around 50 nM.) Thiorphan increased the recovery of released iNT nearly 2-fold and had no effect on iNN. Bestatin produced a 4-fold increase in iNN recovery and was inactive on iNT. Finally, iNT and iNN recoveries were increased up to 4- and 5-fold, respectively, by JMV 390-1. These results show that in the mouse hypothalamus endopeptidase 24.11 participates with other metalloendopeptidases to the degradation of endogenously released NT while endogenously released NN is principally degraded by aminopeptidase(s).

Journal of Agricultural and Food Chemistry, 2009

The consumption of red wine can provide substantial concentrations of antioxidant polyphenols, in... more The consumption of red wine can provide substantial concentrations of antioxidant polyphenols, in particular grape anthocyanins (e.g., malvidin-3-O-β-D-glucoside (1)) and specific red wine pigments formed by reaction between anthocyanins and other wine components such as catechin (3), ethanol, and hydroxycinnamic acids. In this work, the antioxidant properties of red wine pigments (RWPs) are evaluated by the DPPH assay and by inhibition of the heme-induced peroxidation of linoleic acid in acidic conditions (a model of antioxidant action in the gastric compartment). RWPs having a 1 and 3 moieties linked via a CH 3-CH bridge appear more potent than the pigment with a direct 1-3 linkage. Pyranoanthocyanins derived from 1 reduce more DPPH radicals than 1 irrespective of the substitution of their additional aromatic ring. Pyranoanthocyanins are also efficient inhibitors of the heme-induced lipid peroxidation, although the highly hydrophilic pigment derived from pyruvic acid appears less active.

Revue française d'oenologie, 2015

Rapid Communications in Mass Spectrometry, 2019

RationaleThe analysis of tannins is currently usually done by liquid chromatography after the che... more RationaleThe analysis of tannins is currently usually done by liquid chromatography after the chemical depolymerization of tannins. However, one of the main limitations of this method is the difficulty in specifically detecting each constitutive tannin monomer in a complex matrix, as numerous compounds co‐elute with the monomers, thereby compromising the analysis.MethodsThe depolymerization of tannins under acidic conditions and in the presence of thioglycolic acid releases the various constitutive monomers, either as terminal units or as extension units. The tannin subunits were then quantified using extracted‐ion chromatogram (EIC) mass spectrometry, which required the determination of the ionization efficiency of the monomers. Thus, we used AgBF4‐assisted coupling for the hemisynthesis of the noncommercial epicatechin gallate dimer.ResultsThe EIC showed that the derivatives of the extension units were twice as ionized as the terminal units. Unlike the UV chromatograms, this new E...

Journal of Food Measurement and Characterization, 2019

Proanthocyanidins (PAs) and anthocyanins contents of four different red grape pomaces (GPs) from ... more Proanthocyanidins (PAs) and anthocyanins contents of four different red grape pomaces (GPs) from Morocco were analysed using chromatographic methods. The GP skin pigments characteristics were determined using spectroscopic methods while their antioxidant activities were determined using both spectroscopic methods as ABTS and DPPH radical cations, ferric reducing/antioxidant power (FRAP) and electrochemical technique: cyclic Voltammetry (CV). The PA of seeds extracts varied significantly among the types of GP and ranged from 56.1 ± 0.3 mg g −1 dry weight (DW) in Cot to 88.4 ± 2.3 mg g −1 DW in non-fermented Cabernet Sauvignon (CSNF). The skins of CSNF contained the highest levels of PAs (22.1 ± 0.3 mg g −1 DW). The PAs average degree of polymerization distribution ranged from 2 to 45 subunits for the skins and from 2 to 12 subunits for the seeds. The maximum anthocyanins amounts and antioxidant activities were measured in Cot skin extracts (32.8 mg g −1 DW, DPPH: 0.23 mmol Trolox mg g −1 DW; ABTS: 0.38 mmol Trolox mg g −1 DW and CV: 1.73 × 10 −3 mA V) followed by Arinarnoa skin extracts which had the maximum corrected pigments (14.8 ± 0.1) and color power (152.4 ± 4.6 Unit color). The principal components analysis (PCA) of GP skins showed three different groups relevant to anthocyanins, PAs content, color and antioxidant properties.

Journal of Food Chemistry and Nanotechnology, 2017

Red press wine is collected after pressing solid parts (seed and skin) of grapes pomaces. Higher ... more Red press wine is collected after pressing solid parts (seed and skin) of grapes pomaces. Higher pressure induces more colorful, astringent, bitter and rustic wines. This is caused by the presence of undesirable phenolic compounds. To overcome this problem, the most common practice used in wine industry is the oenological treatment which enhances the clarity, stability and the wine taste. In the present work, press wines were separately submitted to four different treatments: micro-oxygenation and the addition of three fining agents: gelatin, polyvinylpolypyrrolidone (PVPP) and pea protein. The phenolic total index decreased (8%) significantly (P<0.05) for gelatin treatment, the PVPP based formulation treatment led to the largest loss (8%) in color intensity, (12%) in redness (a*), (9%) in polymeric pigments and increasing to 9% lightness (L*). Unlike micro-oxygenation which has decreased (5%) the color intensity. For the monomeric anthocyanins, the greatest reduction of acylated and coumaroylated anthocyanins at bottling and glucoside anthocyanidins after five months of storage was observed for both basic PVPP and gelatin.

LWT - Food Science and Technology, 2017

To improve the sensory quality of Moroccan red press wines, press wines were separately submitted... more To improve the sensory quality of Moroccan red press wines, press wines were separately submitted to micro-oxygenation and three fining agents (gelatin, Polyvinylpolypyrrolidone (PVPP) based formulation and pea protein) treatments at the winery CHATEAU ROSLANE, Morocco. The results showed that each treatment has a distinct behavior in relation with interactions and precipitation monomeric flavan-3-ol and fractions apparent and total condensed tannins. The fining agent corresponding to the vegetable protein has a greater affinity with the fraction of oligomeric condensed tannins with apparent aDP: 3.2. However, gelatin and PVPP based fining agent have an affinity with the catechin and epicatechin as well as with the fraction of polymeric tannins (apparent aDP: 6.6). For the structural parameters of proanthocyanidins, no significant differences were found out in global aDP and percentage of prodelphinidin between the different treatments. The global percentage of galloylation appeared slightly affected, while the global percentage of oxidized proanthocyanidins increased (9%) significantly (P<0,05) for micro-oxygenation treatment, unlike the fining agent has basic vegetable protein has decreased 36% the percentage of oxidation. For the Saliva Precipitation Index (SPI) and sensory analysis, the greatest reduction of SPI, bitterness and astringency was observed for both basic PVPP and vegetable protein fining agents.

HAL (Le Centre pour la Communication Scientifique Directe), Jun 15, 2011

Dans le cadre de l'élaboration de résines époxy biosourcées nous avons cherché à synthétiser des ... more Dans le cadre de l'élaboration de résines époxy biosourcées nous avons cherché à synthétiser des prépolymères époxy biosourcés à base de tanins. Nous avons dans un premier temps étudié l'époxydation des tanins et pour cela étudié la réactivité de la catéchine, molécule modèle des tanins, dans le cadre d'une réaction d'époxydation avec l'épichlorohydrine afin de former des éthers de glycidyl. Le glycidyl éther de catéchine (GEC) a ensuite été formulé avec un durcisseur amine et les propriétés des résines obtenues ont été comparées à celles d'une résine commerciale. Par exemple, lorsqu'on incorpore du GEC dans une résine à base de diglycidyl éther de bisphénol A (DGEBA) à hauteur de 50%, le GEC ne modifie pas la température de transition vitreuse. De plus les taux de gonflement des résines contenant du GEC sont plus faibles que le taux de gonflement d'une résine 100% DGEBA, ce qui traduit un taux de réticulation plus élevé et des distances entre les noeuds du réseau plus faibles. Parallèlement à cette étude, le développement d'un matériau composite basé sur des ressources renouvelables a fait l'objet de travaux en vue de son utilisation pour les profilés de fenêtres. Des profilés plats à plus de 60% volumique de fibres ont ainsi été réalisés par pultrusion de fibres végétales de lin et de polyester. Toutefois, la pultrusion du lin avec des résines époxy s'est révélée moins évidente. La rigidité du matériau UP/lin est de 35 GPa et sa conductivité thermique est de 0,3W/m.K.

HAL (Le Centre pour la Communication Scientifique Directe), Jun 17, 2019

Food Chemistry, Nov 1, 2010

The impact of moderate oxygen exposure after bottling on wine phenolic composition and colour pro... more The impact of moderate oxygen exposure after bottling on wine phenolic composition and colour properties has been investigated on four Grenache red wines showing high and low phenolic contents, obtained by flash release (FR) and traditional soaking (Trad), respectively, and processed with (Mox, 4.6mgl−1 O2) or without (noMox) micro-oxygenation. Four oxygen transfer rate (OTR) conditions (0.8, 1.9, 8.0, and 11.9μl oxygen/bottle/day) were ensured by using synthetic closures with controlled oxygen permeability and storage under controlled atmosphere. Wine phenolic composition and colour were monitored by triplicate analysis of bottles sampled at bottling (T0) and after 5 and 10months of ageing. Phenolic composition was determined by reverse-phase HPLC-DAD–MS analysis, performed directly on the wines and after phloroglucinolysis for proanthocyanidins. Colour was evaluated by UV–visible spectrophotometry and tristimulus colorimetry. At T0, FR wines contained larger amounts of catechins, proanthocyanidins and hydroxycinnamic acids and slightly lower amounts of anthocyanins than the Trad wines while the Mox wines showed higher levels of some derived pigments, especially carboxypyranoanthocyanins, resulting from reactions of anthocyanins with pyruvate. During ageing, a progressive decrease of proanthocyanidins and hydroxycinnamic acid concentrations was observed, independently of OTR. In contrast, the loss of free SO2, flavan-3-ol monomers and the conversion rate of anthocyanins to new pigments, especially into sulphite bleaching resistant pigments, increased with OTR levels. Among derived pigments, carboxypyranoanthocyanins levels increased both with micro-oxygenation and with OTR and can be considered as oxidation markers while flavan-3-ol–anthocyanin adducts were formed in larger amounts with lower oxygen exposure.

Journal of Agricultural and Food Chemistry, Apr 29, 2005

A red wine, made from Cabernet Sauvignon (60%) and Tannat (40%) cultivars, was fractionated by hi... more A red wine, made from Cabernet Sauvignon (60%) and Tannat (40%) cultivars, was fractionated by high speed countercurrent chromatography (HSCCC). The biphasic solvent system consisting of tert-butyl methyl ether/n-butanol/acetonitrile/water (2/2/1/5, acidified with 0.1% trifluoroacetic acid) was chosen for its demonstrated efficiency in separating anthocyanins. The different native and derived anthocyanins were identified on the basis of their UV-visible spectra, their elution time on reversed-phase high-performance liquid chromatography (HPLC), and their mass spectra, before and after thiolysis. The HSCCC method allowed the separation of different families of anthocyanin-derived pigments that were eluted in different fractions according to their structures. The hydrosoluble fraction was almost devoid of native anthocyanins. Further characterization (glucose quantification, UV-visible absorbance measurements) indicated that it contained flavanol and anthocyanin copolymers in which parts of the anthocyanin units were in colorless forms. Pigments in the hydrosoluble fraction showed increased resistance to sulfite bleaching and to the nucleophilic attack of water.

Journal of Agricultural and Food Chemistry, Aug 15, 2007

Optimization of polyphenol extraction from grape skin, seed, and pulp was performed on Vitis vini... more Optimization of polyphenol extraction from grape skin, seed, and pulp was performed on Vitis vinifera L. cv. Pinot Noir, by response surface methodology using a Doehlert design. An acidified mixture of acetone/water/methanol was the best solvent for simultaneous extraction of major polyphenol groups from all berry parts, while optimum extraction times and solid-to-liquid ratios varied according to the part. The determined composition from the model agreed with independent experimental results. Analysis of the three Champagne grape varieties showed that proanthocyanidins were the major phenolic compounds in each part (60-93%). The total berry proanthocyanidin content was highest in Pinot Meunier (11 g kg-1) and lowest in Chardonnay (5 g kg-1), but Pinot Meunier pulp contained lower amounts of proanthocyanidins and phenolic acids (210 and 127 mg kg-1 berry, respectively) than that of the other two varieties. The berry anthocyanin content was equivalent in both Pinot Noir and Pinot Meunier (632 and 602 mg kg-1 , respectively).

HAL (Le Centre pour la Communication Scientifique Directe), Jun 14, 2001

Annals of Botany

Background and Aims Condensed tannins, responsible for berry and wine astringency, may have been ... more Background and Aims Condensed tannins, responsible for berry and wine astringency, may have been selected during grapevine domestication. This work examines the phylogenetic distribution of condensed tannins throughout the Vitaceae phylogenetic tree. Methods Green berries and mature leaves of representative true-to-type members of the Vitaceae were collected before ‘véraison’, freeze-dried and pulverized, and condensed tannins were measured following depolymerization by nucleophilic addition of 2-mercaptoethanol to the C4 of the flavan-3-ol units in an organic acidic medium. Reaction products were separated and quantified by ultrahigh pressure liquid chromatography/diode array detection/mass spectrometry. Key Results and Conclusions The original ability to incorporate epigallocatechin (EGC) into grapevine condensed tannins was lost independently in both the American and Eurasian/Asian branches of the Vitaceae, with exceptional cases of reversion to the ancestral EGC phenotype. This ...

Calyces of Hibiscus sabdariffa are traditionally used to prepare a red beverage rich in anthocyan... more Calyces of Hibiscus sabdariffa are traditionally used to prepare a red beverage rich in anthocyanins (delphinidinand cyanidin-3-O-sambubioside) by decoction in water. These molecules are subjected to degradation during storage leading to a undesirable color intensity decay and change from red to brown in few months. The chemical origins of this quality loss have been already identified as scission and mainly condensation reactions leading to uncolored or brown polymers of anthocyanins (Sinela et al., 2016). Scission and condensed products are known to be instable and/or of various molecular weight. Their concentration is therefore very difficult to get unless numerous time- and money-consuming analysis. An alternative of getting mecanistic and kinetic insigth into anthocyanin degradation during processing or storage is the UV-VIS spectra analysis with chemometric tools. Indeed, UV-VIS spectra are easy to get, but may be complex to interpret as they result from the contribution of al...

Journal of Biotechnology, 2021

Yarrowia lipolytica strains PGC01003 and PGC202 engineered for succinic acid production were stud... more Yarrowia lipolytica strains PGC01003 and PGC202 engineered for succinic acid production were studied and compared to the wild type strain W29. For the first time, these two strains were characterized in a chemically defined medium. Strain growth and organic acid production were investigated in fed-batch mode with glycerol as carbon and energy source. This study evaluated the impact of nitrogen deficiency strategy to redirect carbon flux toward succinic acid synthesis. Strain PGC01003 produced 19 g L-1 succinic acid with an overall yield of 0.23 g g-1 and an overall productivity of 0.23 g L-1 h-1, while strain PGC202 produced 33 g L-1 succinic acid with an overall yield of 0.12 g g-1 and a productivity of 0.57 g L-1 h-1. Nitrogen limitation effectively stopped biomass growth and increased succinic acid yield of PGC01003 and PGC202 by 18% and 62%, respectively. However, the specific succinic acid production rate was reduced by 77% and 66%, respectively.

Acta Horticulturae, 2019

Grape condensed tannins (proanthocyanidins) are phenolic substances of utmost importance in the s... more Grape condensed tannins (proanthocyanidins) are phenolic substances of utmost importance in the sensory characteristics of wine. Not only does their final concentration affect the fermentation process, but their structure also greatly influences the negative attribute of astringency. Determining the exact amount of proanthocyanidins in the grape pericarp is a real challenge, and a prerequisite in any breeding research program aimed at the improvement of the quality of grape berry tannins. We analyzed pericarp condensed tannins in four species of Asian and American wild grape vines in comparison with four accessions of the domestic grape vine, Vitis vinifera. The mass of tannins per berry ranged from 0.1 to 1.2% FW; however, the relative mole percentage of epigallocatechin in Asian species was 10 times lower than in American species and the domestic grape vine, while the tannin galloylation degree of American vines was 4 and 10 times higher than in domestic and Asian vines, respectively.

Food Chemistry, 2019

This study aims to monitor composition changes in an anthocyanin-rich beverage during storage by ... more This study aims to monitor composition changes in an anthocyanin-rich beverage during storage by the means of UV-VIS measurements associated with a multi-curve resolution procedure. Hibiscus sabdariffa extract was stored at 37°C for 50 days and UV-VIS spectra were measured on the extract and the fractions of the extract every 5 days. MCR was carried out in two steps, first with the fraction and then the extract spectra. The results enabled the main polyphenols initially present to be identified, anthocyanins and chlorogenic acid, but also found the nature of the main degradation products: the polymers from anthocyanin condensation and scission products. In addition, comparison with HPLC analysis results showed that the MCR procedure recovered the correct shapes of the concentration profiles particularly of anthocyanin and polymer kinetics during storage. This work gives perspective for the use of a rapid and efficient technique to monitor pigment-rich beverage processing or storage.