[Show abstract][Hide abstract] ABSTRACT: Background and Aims: Water deficit is known to influence berry development as well as flavonoid metabolism. The aim of this study was to investigate the influence of pre- and post-veraison water stress on the proanthocyanidin and anthocyanin accumulation on berry samples selected at comparable physiological maturity, especially after veraison while avoiding sugar influence.
Methods and Results: Three irrigation treatments were applied by a drip irrigation system on three rows of 30 vines from an experimental Shiraz vineyard. Pre-veraison water stress had no effect on total proanthocyanidin accumulation but increased accumulation of all anthocyanins except malvidin and p-coumaroylated derivatives, whereas post-veraison water stress enhanced the overall anthocyanin biosynthesis, particularly malvidin and p-coumaroylated derivatives.
Conclusions: Pre- and post-veraison water stress affected the anthocyanin composition differently, suggesting a differential regulation of the genes involved in the last steps of anthocyanin biosynthesis pathway.
Significance of the Study: The study identifies the effect of pre- and post-veraison water stress while avoiding sugar influence on anthocyanin accumulation which could be maximised since both stresses differently impacted hydroxylation and methylation of anthocyanins.
Australian Journal of Grape and Wine Research 01/2011; 17(1):90 - 100. DOI:10.1111/j.1755-0238.2010.00121.x · 1.82 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Flavan-3-ols make up a large group of flavonoid compounds, encountered in several tissues of plants and involved in reactions
against various biotic aggressions, such microbial pathogens (bacteria and fungi), insects and larger herbivores (Dixon et
al. 2005). They comprise monomers (often called catechins), and oligomers and polymers, called condensed tannins or proanthocyanidins
(PAC). In grapevine they are present in wood, stems, leaves, and in fruits (Boukharta et al. 1988, Souquet et al. 2000, Bogs
et al. 2005, Tesnière et al. 2006). They are quantitatively the most abundant secondary metabolites of grape berries. They
are extracted during winemaking and are a major qualitative factor in red wines because of their implication in colour stability,
astringency and bitterness.
[Show abstract][Hide abstract] ABSTRACT: An extraction method on grape berry was optimized for the total flavan-3-ol content measurement with regard to the nature of the sample and the duration of its extraction. This extraction was performed for the first time on the whole pericarp. Flavan-3-ol extractions were achieved on Shiraz ripe samples of pericarp versus skin within different durations: the best results were obtained for the whole pericarp and 1 h duration. Therefore, this more convenient protocol was used to investigate the flavan-3-ol content at different stages through berry development, in parallel with the abundance of transcripts involved in their biosynthesis. Furthermore, flavan-3-ol extractions on pericarp analysis confirmed their presence in both pulp and skin. For the first time, the flavan-3-ol biosynthesis in pulp was demonstrated with both biochemical and transcriptomic analyses since the presence of leucoanthocyanidin reductase (LAR2) and anthocyanin reductase (ANR) transcripts was revealed by real-time PCR. In addition, the percentage of epigallocatechin was different in pulp and skin.
Journal of Agricultural and Food Chemistry 08/2008; 56(14):5896-904. DOI:10.1021/jf800028k · 2.91 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: 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).
Journal of Agricultural and Food Chemistry 10/2007; 55(18):7224-33. DOI:10.1021/jf071301w · 2.91 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Flavor compounds from ripe mango puree were studied upon cross-flow microfiltration on microporous alumina membrane and subsequent concentration of the permeate by reverse osmosis. Terpene hydrocarbons, the major (−98%) volatiles of the puree, were qualitatively and quantitatively recovered in the pulpy microfiltration retentate. The more polar volatiles (−2%) were diversely affected. Most of the oxygenated terpene derivatives were also retained in the microfiltration retentate. C13 norisoprenoids and phenols increased, likely by chemical degradation of carotenoids and phenolic acids, respectively.
[Show abstract][Hide abstract] ABSTRACT: ABSTRACT Purple passion fruit were processed by flash vacuum-expansion in comparison with a single-strength juice. A puree was obtained with about 50%/fruit weight yield, which is 2-fold that obtained for the reference juice. Color and cell-wall polysaccharides of the products were analyzed, and their rheological properties were investigated. The red-purple puree was enriched in anthocyanins and alcohol-insoluble residue. The puree had higher consistency and viscosity, which was related to its alcohol-insoluble residue and starch contents.
[Show abstract][Hide abstract] ABSTRACT: Purple passion fruits were processed by the flash vacuum-expansion process. Volatile components were analyzed in purees from steam-heated fruits, steam-heated then vacuum-expanded fruits and their aromatic liquors, and fruit rind, in comparison with a reference single-strength juice. After steam heating, the puree was enriched in esters arising from the rind. Steam-heated then vacuum-expanded fruits yielded a puree impoverished in volatiles due to evaporation of approximately 10% of water. These volatile compounds were mostly recovered in aromatic liquors.
Journal of Agricultural and Food Chemistry 01/2001; 48(12):6210-4. DOI:10.1021/jf000645i · 2.91 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Ripe mango puree (Smith cultivar) was treated with fungal polysaccharidases containing pectinolytic, hemicellulolytic, and cellulolytic activities for 2 h at 50 degrees C. A loss of 30% of the cell wall material (CWM) was measured. CWM polysaccharides were hydrolyzed to varying degrees: 88, 65, and 65% of, respectively, galacturonic acid-, arabinose-, and rhamnose-containing polymers were hydrolyzed, whereas 50% of cellulose was degraded. After 30 min of treatment, the ethanol precipitation test on the serum was negative, indicating that pectic substances were rapidly hydrolyzed. Oligogalacturonic acids (degree of polymerization, 1-12) were observed in the serum. A viscosity drop of 90% was measured after 2 h, confirming the dominant role of pectic substances in puree viscosity.
Journal of Agricultural and Food Chemistry 08/2000; 48(7):2713-6. DOI:10.1021/jf990924+ · 2.91 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Free and glycosidically linked volatile components of four mango cultivars of polyembryonic (M'Bingué and Tête de Chat) and monoembryonic (Amélie and Palmer) seed origins were examined. Eighty-five free volatile components were identified in the four cultivars, of which 33 are newly described as mango volatile compounds. Terpene hydrocarbons (104, 139, 26, and 35 mg/kg of fresh pulp, respectively) were the major volatiles of all four cultivars (>90% of the total volatiles), the dominant terpenes being (Z,E)-ocimenes (70%) in Amélie and car-3-ene (80%) in the other cultivars. Free oxygenated volatiles, mainly represented by monoterpenoids, and C 13 norisoprenoids were present in all cultivars, the African Tête de Chat cultivar being by far the richest (12.3 mg/kg). Of the 29 aglycons characterized, 12 were identified for the first time as mango bound volatiles. Again, the Tête de Chat cultivar was the richest (2.1 mg/kg) with monoterpenoids and C 13 norisoprenoids as the main glycosidically linked volatile compounds.
Journal of Agricultural and Food Chemistry 03/1998; 46(3). DOI:10.1021/jf9705781 · 2.91 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Mature green fruits from monoembryonic (Amélie and Palmer) and polyembryonic (M'Bingue and Tête de Chat) mango cultivars were initiated to ripen with ethylene (10 ppm, 24 h) and then left to reach full ripeness (6 days). After elimination of skin and kernel, pulp was added with HEPES (1/5, w/w) and centrifuged. Soluble polysaccharides were obtained from the supernatant by precipitation with ethanol and freeze-drying. Cell wall material (CWM) was isolated from the pellet by the buffered phenol procedure and further enzymatically destarched. Soluble polysaccharides (0.5−0.8%/pulp fresh weight) were essentially highly esterified pectic substances (uronic acids content 50−60%; degree of methyl esterification 89−97%) and their molecular weights were higher in the polyembryonic cvs. CWM, 1%/pulp fresh weight, was mainly built of cellulose (20%) and highly esterified pectic substances (uronic acids 13−24%; degree of esterification 63−73%). Hemicellulosic glucans were more abundant in the monoembryonic (9%) than in the polyembryonic (4%) cultivars. Keywords: Mango; Mangifera indica L.; cultivars; pulp; soluble polysaccharides; cell wall material
Journal of Agricultural and Food Chemistry 09/1996; 44(9). DOI:10.1021/jf9507506 · 2.91 Impact Factor