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International audience; Grenache, Syrah, Carignan Noir, Mourvedre, Counoise and Alicante Bouchet grape seeds and skins, harvested in 2009 and 2010 in the Rhone valley area of France, and their respective pomaces remaining after vinification, were analyzed for their phenolic composition and antioxidant activity. The polyphenol content was quantified by HPLC and the Folin-Ciocalteu assay. The antioxidant potential was measured with four different assays: ORAC, FRAP, ABTS and DPPH. Seeds contained higher amounts of total polyphenols, up to 44.5 mg of gallic acid equivalent [GAE]/g dry weight in Alicante pomace, than skin extracts. The maximum total phenolic in skins was 31.6 mg GAE/g dry weight detected in 2010 Alicante pomace. Seeds also had the highest antioxidant capacity. HPLC analysis revealed that, despite the vinification process, pomaces still contained an appreciable amount of proanthocyanidins as well as several anthocyanin glycosides. Alicante and Syrah proved to be the varieties of most interest in terms of their potential development for nutraceutical purposes.

Grape (Vitis vinifera) is one of the most cultivated fruit crops in the world, with an approximate annual production of ∼64 million metric tons in 2010 (OIV, 2011). Grapes composition in polyphenols and their extractability which is far from complete and typically reaching only 30–40% depend on grape varieties, vineyard location and the technological parameters during wine making process including destemming, crushing, maceration and pressing. Therefore, grape pomace potentially constitutes a very abundant and relatively inexpensive source of a wide range of polyphenols including monomeric and oligomeric flavan3-ols (proanthocyanidins) as well as anthocyanins (glucosides, acetylated glucosides and coumarylic glucosides). Moreover, it has been evaluated as a potential source of antioxidant polyphenols which could be used as nutraceuticals or food additives. Actually, phenolic compounds are known to have some health benefits such as a chemopreventive role toward cardiovascular, cancer, and degenerative diseases. In order to valorize wine by-products from Rhone Valley area, grape and pomace seeds and skins from red wine cultivars at maturity from the vintage 2009 and 2010 (Grenache, Syrah, Carignan, Mourvedre, Counoise and Alicante) have been characterised for their phenolic contents (total phenol contents, tannin and anthocyanin contents total and individuals; quantification of monomeric and oligomeric proanthocyanidins as well as some anthocyanins (glucosides, acetylated glucosides and coumarylic glucosides)). Ratio of initial phenolic compounds from grape to pomace was also estimated. The comparison of several wine industry by-products with their respective grapes provided evidence that grape seed and skin pomace extracts still contained appreciable amounts of flavanol-3-ols and anthocyanins even after the fermentation process. Quantitative and qualitative distribution of polyphenols in grape pomaces showed significant differences through varieties. Seed extracts from grapes and pomaces contain exceptionally high amounts of total polyphenols than skin’s extracts. This study evidenced seeds from Grenache, Syrah and Alicante and skins from Syrah, Carignan and Alicante as the most interesting fractions to be valorized because of their richest contents in polyphenols compared to the other assessed fractions and varieties. This work further supports that grape pomaces obtained after vinification still retained a significant amount of polyphenols of which level depends largely on the vintage. The use of this by-product would constitute a promising natural source of available polyphenols which could be included in nutraceutical formulation. Activity effects of grape by-products on a chronic disease model with hypertension are given. ∗Corresponding author: Pierre-louis Teissedre, Universite Bordeaux Segalen, Institut des Sciences de la Vigne et du Vin, EA 4577USC Oenologie 1366 INRA-UBS-IPB, 210, chemin de Leysotte, CS 50008, 33882 Villenave d’Ornon Cedex, France. E-mail: p.teissedre@u-bordeaux2.fr.

Background and Aims: The impact of grey mould (Botrytis cinerea (B. cinerea)) was quantified on chemical, phenolic and sensory qualities of grapes, derived musts and wines. Methods and Results: Analyses were carried out by using naturally or artificially infected grape berries at ripeness or overripeness. In grape seeds, chemical analyses revealed no major differences between healthy and rotten grapes. In grape skins of Botrytis-affected berries, concentrations of all the phenolic compounds (anthocyanins and proanthocyanidin monomers, dimers and trimer) decreased drastically. Mean degree of polymerization of the proanthocyanidin polymeric fraction was also affected in skins. Chemical analyses of musts and wines made with different percentages of rotten berries showed a moderate impact of the pathogen on their phenolic composition. Nevertheless, sensory analyses underlined a loss of wine sensory quality perceptible from a threshold as low as 5% of Botrytis-affected grapes onwards. Conclusion: Phenolic variations and the associated negative impact in grapes, derived musts and wines may be related to oxidation phenomena from B. cinerea. The main effects of severity/age of grey mould and the level of berry maturity are also discussed. Significance of the Study: B. cinerea drastically affects the phenolic and organoleptic properties of grape skins and derived wines. Therefore, prophylactic actions early in the vineyard, evaluation of the sanitary status of the harvested grapes and berry sorting are primordial even under low disease pressure.

Background and Aims: The impact of Esca, a cryptogamic disease affecting woody tissues of grapevines (trunk, branches and shoots), was investigated on phenolic and sensory qualities of Cabernet Sauvignon grapes, derived musts and wines. Methods and Results: Global phenolic analyses revealed no major difference between healthy and affected grapes whereas high-performance liquid chromatography analyses showed decreases in the skin concentrations of catechin and epicatechin and of anthocyanins for the two vintages assessed. Proanthocyanidin characteristics, and particularly mean degree of polymerisation, were strongly decreased in skin proanthocyanidin polymeric fractions. Chemical analyses of wines made with different percentages of fruit from Esca infected grapevines confirmed the moderate impact of Esca on phenolic composition. Nevertheless, sensory analyses revealed a loss of wine sensory quality perceptible with as little as 5% of affected fruit in wines. Conclusions: Phenolic variations in grapes and in derived wines may be related to changes to grapevine physiology caused by Esca fungi that impact on flavonoid metabolism. The chemical and sensory variations between wines can also be related to the delayed ripening delay of fruit from Esca infected grapevines. Significance of the Study: Esca moderately affected the phenolic composition of grapes and decreased the sensory quality of wines, suggesting a dramatic increase in the economic importance of Esca if no control methods are found.

International audience; The proanthocyandin composition of skins and seeds of Bordeaux Merlot (M) and Cabernet Sauvignon (CS) grapes was evaluated by HPLC-UV-fluorescence for four consecutive vintages (2006 to 2009). The results indicated a strong vintage effect on the tannin profile of each variety. However, and in spite of the vintage effect, some tannin characteristics such as mDP, %G and %P allow discrimination of both Bordeaux varieties. The same analyses were carried out for the 2009 vintage of five Mediterranean grape varieties (Syrah, Grenache, Mourvedre, Carignan and Counoise). The results demonstrated differences among these five varieties. Syrah appeared to exhibit the highest concentrations of flavanol monomers and dimmers, especially in skins. The comparison study between Bordeaux and Mediterranean grape varieties for the same vintage (2009) revealed that mDP and %G for seed extracts were parameters specific to each vineyard area.

Observational studies indicate that the intake of polyphenol-rich foods improves vascular health, thereby significantly reducing the risk of hypertension and cardiovascular disease (CVD). Therefore, the aim of this study was to analyse the remained potential of grape by-products from important Rh&ocirc, ne Valley red wine cultivars: Grenache, Syrah, Carignan, Mourv&egrave, dre and Alicante. For that, six different extracts from grape pomaces, selected by their antioxidant activity, were studied in vivo during six weeks with spontaneously hypertensive rats (SHR). Extracts used in SHR1, SHR2 and SHR6 groups presented a &laquo, rebound effect &raquo, on systolic blood pressure, whereas the other extracts do not change it significantly. The bioavailability of Grenache (GRE1) (EA70) seed pomace extract (SHR1 group), Mouvendre (MOU) (EA70) skin pomace extract (SHR5 group) and Alicante (ALI) (EA70) skin pomace extract (SHR6 group) was studied by High Performance Liquid Chromatography with Photodiode Array detector and Electrospray Ionization Mass Spectrometer (HPLC-PDA-ESI-MSn) in urine, plasma and tissues to search differences on the metabolism of the different extracts intake.

cope The role of colonic microbiota in the breakdown of hesperetin, naringenin, and ferulic acid, compounds found as glycosides in orange juice, was investigated using an in vitro fermentation model. Methods and results Test compounds were incubated with human fecal slurries cultured under anaerobic conditions, and the production of phenolic acid catabolites were monitored by GC-MS and HPLC-MS2. Hesperetin was converted to 3-(3′-hydroxy-4′-methoxyphenyl)propionic acid, 3-(3′,4′-dihydroxyphenyl)propionic acid, and 3-(3′-hydroxyphenyl)propionic acid while 3-(phenyl)propionic acid was the major end product derived from naringenin. The data obtained are compared to our previously published data on urinary excretion of phenolic and aromatic acids after acute orange juice consumption (Pereira-Caro et al. Am. J. Clin. Nutr. 2014, 100, 1385–1391). Catabolism pathways are proposed for events occurring in the colon and those taking place postabsorption into the circulatory system with particular reference to the excretion of 3-(3′-hydroxy-4′-methoxyphenyl)hydracrylic acid, which is not formed in fecal incubations. Ferulic acid was also degraded by the colonic microflora being converted principally to 3-(3′-methoxy-4′-hydroxyphenyl)propionic acid, a phenolic acid that appears in urine after orange juice consumption. Conclusion The study provides novel information on the potential involvement of the colonic microbiota in the overall bioavailability of orange juice (poly)phenols through the production of phenylpropionic acids and subsequent hepatic conversions that lead to hippuric acid and its hydroxylated analogues.

National audience

National audience; Étude de l'impact de Botrytis cenerea sur la composition chimique de raisins de Merlot, de moûts et vins vinifiés à partir de différents pourcentages de raisins affectés par le Botrytis.

International audience; Grape and wine phenolics are structurally diverse, from simple molecules to oligomers and polymers usually designated as tannins. They have an important impact on the organoleptic properties of wines, that's why their analysis and quantification are of primordial importance. The extraction of phenolics from grapes and from wines is the first step involved in the analysis. Then, several analytical methods have been developed for the determination of total content of phenolic, while chromatographic and spectrophotometric analyses are continuously improved in order to achieve adequate separation of phenolic molecules, their subsequent identification and quantification. This review provides a summary of evolution of analysis of polyphenols from grapes, wines and extracts.

International audience; A rapid and simple reverse-phase liquid chromatography coupled with fluorescence detection is proposed for the rapid simultaneous analysis of three monomeric flavanols and six procyanidins (i.e., five dimers and one trimer) in wine. Good resolution and low detection limits were obtained for (+)-catechin, (-)-epicatechin, (-)-epicatechin 3-O-gallate, dimers B1, B2, B3, B4 and B2-gallate and trimer C1. The method has been validated for linearity, precision and accuracy. Good performances in terms of selectivity and sensitivity have been also achieved. Moreover, new fluorimetric method has been developed in order to achieve the quantification of (-)-epicatechin 3-O-gallate and procyanidin B2-gallate by fluorescence detection.

M. A. Silva I. Ky M. Jourdes P.-L. Teissedre (&) Unite de Recherche Oenologie, EA 4577, USC 1219 INRA, Faculte d’Oenologie, Institut des Sciences de la Vigne et du Vin, Universite Bordeaux Segalen, 210 chemin de Leysotte, CS 50008, 33882 Villenave d’Ornon Cedex, France e-mail: p.teissedre@u-bordeaux2.fr Table 2 Validation parameters determined for the proanthocyanidins liquid chromatography coupled with fluorescence detection method