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Montpellier, France

Koffi E.N.,Nangui Abrogoua University | Meudec E.,CNRS Sciences for Enology | Adje F.A.,Laboratoire Of Procedes Industriels | Lozano P.R.,CIRAD - Agricultural Research for Development | And 2 more authors.
Journal of Applied Research on Medicinal and Aromatic Plants | Year: 2015

Tectona grandis leaf extracts obtained at pilot scale processes (ultrasound-assisted extraction, cross-flow microfiltration, reverse osmosis concentration) contains phenolic compounds that exhibit antioxidant properties. The final reverse osmosis concentrate extract presented higher content of polyphenol (21,080 ± 117 μmolg-1 GAE) and antioxidant capacity (8490 ± 29 μmolg-1 TE) comparatively to crude extract (1300 ± 12 μmolg-1 GAE for polyphenol and 430 ± 2 μmolg-1 TE for antioxidant activity) or cross flow microfiltration extract (1170 ± 10μmolg-1 GAE for polyphenol and 400 ± 10 μmolg-1 TE for antioxidant). The concentration factors of polyphenol and antioxidant capacity were 18 and 21, respectively. High-performance liquid chromatography (HPLC) coupled to electrospray ionization mass spectrometry (ESI-MS) detection negative ion mode has been used to identify and characterized polyphenols in the concentrate extract of T. grandis leaves. Seven phenolic acids and flavonoids were characterized. Verbascoside (phenolic acid) was described as the most abundant phenolic compounds in this concentrate extract. Two drying technologies (freeze-drying and spray-drying) were used to obtained stable powder from concentrate extract. The effect of these drying technologies on phenolic compounds and antioxidant activity were studied. Freeze-drying presented a good recovery of phenolic compounds and antioxidant capacity. This drying technology could be used for preservation of T. grandis extract. © 2015 Elsevier GmbH.

Zago E.,CIRAD - Agricultural Research for Development | Durand E.,CIRAD - Agricultural Research for Development | Barouh N.,CIRAD - Agricultural Research for Development | Lecomte J.,CIRAD - Agricultural Research for Development | And 2 more authors.
Journal of Agricultural and Food Chemistry | Year: 2015

4-Vinyl guaiacol (2) was lipophilized through the electrophilic addition of peracids to its vinylic double bond. Those peracids were formed in situ, by the Candida antarctica lipase-B-assisted perhydrolysis of carboxylic acids ranging from C2 to C18, in hydrogen peroxide solution. The addition of peracids with 4-8 carbons in their alkyl chains led to the formation of two regioisomers, with the prevalence of hydroxyesters bearing a primary free hydroxyl (4c-4e). This prevalence became more pronounced when peracids with longer alkyl chains (C10-C18) were used. In this case, only isomers 4f-4h were formed. The antioxidant activity of the resulting hydroxyesters was assessed by means of the conjugated autoxidizable triene (CAT) assay, and it was found out that the 4-vinyl guaiacol antioxidant activity was significantly increased by grafting alkyl chains with 2-8 carbons. © 2015 American Chemical Society.

Almeida P.,New University of Lisbon | Barbosa R.,New University of Lisbon | Zalar P.,University of Ljubljana | Imanishi Y.,Kanto Gakuin University | And 10 more authors.
Molecular Ecology | Year: 2015

The domestication of the wine yeast Saccharomyces cerevisiae is thought to be contemporary with the development and expansion of viticulture along the Mediterranean basin. Until now, the unavailability of wild lineages prevented the identification of the closest wild relatives of wine yeasts. Here, we enlarge the collection of natural lineages and employ whole-genome data of oak-associated wild isolates to study a balanced number of anthropic and natural S. cerevisiae strains. We identified industrial variants and new geographically delimited populations, including a novel Mediterranean oak population. This population is the closest relative of the wine lineage as shown by a weak population structure and further supported by genomewide population analyses. A coalescent model considering partial isolation with asymmetrical migration, mostly from the wild group into the Wine group, and population growth, was found to be best supported by the data. Importantly, divergence time estimates between the two populations agree with historical evidence for winemaking. We show that three horizontally transmitted regions, previously described to contain genes relevant to wine fermentation, are present in the Wine group but not in the Mediterranean oak group. This represents a major discontinuity between the two populations and is likely to denote a domestication fingerprint in wine yeasts. Taken together, these results indicate that Mediterranean oaks harbour the wild genetic stock of domesticated wine yeasts. © 2015 John Wiley & Sons Ltd.

Rienth M.,Montpellier SupAgro | Torregrosa L.,Montpellier SupAgro | Sarah G.,Montpellier SupAgro | Ardisson M.,Montpellier SupAgro | And 2 more authors.
BMC Plant Biology | Year: 2016

Background: Fruit composition at harvest is strongly dependent on the temperature during the grapevine developmental cycle. This raises serious concerns regarding the sustainability of viticulture and the socio-economic repercussions of global warming for many regions where the most heat-tolerant varieties are already cultivated. Despite recent progress, the direct and indirect effects of temperature on fruit development are far from being understood. Experimental limitations such as fluctuating environmental conditions, intra-cluster heterogeneity and the annual reproductive cycle introduce unquantifiable biases for gene expression and physiological studies with grapevine. In the present study, DRCF grapevine mutants (microvine) were grown under several temperature regimes in duly-controlled environmental conditions. A singly berry selection increased the accuracy of fruit phenotyping and subsequent gene expression analyses. The physiological and transcriptomic responses of five key stages sampled simultaneously at day and nighttime were studied by RNA-seq analysis. Results: A total of 674 millions reads were sequenced from all experiments. Analysis of differential expression yielded in a total of 10 788 transcripts modulated by temperature. An acceleration of green berry development under higher temperature was correlated with the induction of several candidate genes linked to cell expansion. High temperatures impaired tannin synthesis and degree of galloylation at the transcriptomic levels. The timing of malate breakdown was delayed to mid-ripening in transgressively cool conditions, revealing unsuspected plasticity of berry primary metabolism. Specific ATPases and malate transporters displayed development and temperature-dependent expression patterns, besides less marked but significant regulation of other genes in the malate pathway. Conclusion: The present study represents, to our knowledge the first abiotic stress study performed on a fleshy fruits model using RNA-seq for transcriptomic analysis. It confirms that a careful stage selection and a rigorous control of environmental conditions are needed to address the long-term plasticity of berry development with respect to temperature. Original results revealed temperature-dependent regulation of key metabolic processes in the elaboration of berry composition. Malate breakdown no longer appears as an integral part of the veraison program, but as possibly triggered by an imbalance in cytoplasmic sugar, when efficient vacuolar storage is set on with ripening, in usual temperature conditions. Furthermore, variations in heat shock responsive genes that will be very valuable for further research on temperature adaptation of plants have been evidenced. © 2016 The Author(s).

Koffi E.N.,CIRAD - Agricultural Research for Development | Koffi E.N.,Nangui Abrogoua University | Le Guerneve C.,CNRS Sciences for Enology | Lozano P.R.,CIRAD - Agricultural Research for Development | And 4 more authors.
Industrial Crops and Products | Year: 2013

Water extracts of Justicia secunda leaves are used by village communities in southern countries to prepare traditional medicines at home. The beverage is usually obtained by boiling the plant in water. On a pilot plant scale, water extracts were processed using an extraction-concentration procedure achieved in a three-step process, including ultrasound-assisted water extraction followed by cross-flow microfiltration of the crude extract and its concentration by reverse osmosis. As the processing conditions were milder than for homemade preparations, the extract obtained was enriched in natural leaf flavonoids. At each step of the pilot plant process, the co-products obtained were analyzed for total polyphenol and total flavonoid contents by the UV-vis spectrophotometric method. The process allowed a better leaf water-extraction of polyphenol compounds than the homemade extraction. The crude extract was concentrated 28 times (v/v) at room temperature by membrane volume reduction, and the total content of polyphenol compounds of the concentrated extract was 17 times higher than those of the crude extract. Individual polyphenol compounds were characterized by HPLC-DAD analysis at λmax=325nm. Additional structure characterization was carried out for the two major flavonoid compounds found (65% of total HPLC-DAD peak area of the flavones-type compounds) in the water extracts by tandem mass spectrometry (LC-ESI-MS2) and by nuclear magnetic resonance (1H NMR, 13C NMR). They were identified as luteolin 7-O-[β-glucopyranosyl-(1→2)-β-rhamnosyl-(1→6)] β-glucopyranoside and luteolin 7-O-[β-apiofuranosyl-(1→2)]-β-xylopyranoside. © 2013 Elsevier B.V.

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