Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 15 de 15
Filter
Add more filters










Publication year range
1.
J Agric Food Chem ; 68(47): 13331-13343, 2020 Nov 25.
Article in English | MEDLINE | ID: mdl-32066244

ABSTRACT

This work investigated the influence of grape variety, vineyard location, and grape harvest maturity, combined with different oxygen availability treatments, on red wine composition during bottle aging. Chemometric analysis of wine compositional data (i.e., wine color parameters, SO2, metals, and volatile compounds) demonstrated that the wine samples could be differentiated according to the different viticultural or bottle-aging factors. Grape variety, vineyard location, and grape maturity showed greater influence on wine composition than bottle-aging conditions. For most measured wine compositional variables, the evolution patterns adopted from the viticultural factors were not altered by oxygen availability treatment. However, contrasting evolution patterns for some variables were observed according to specific viticultural factors, with examples including dimethyl sulfide, phenylacetaldehyde, maltol, and ß-damascenone for vineyard locations, 2-methylbutanal, 1,4-cineole, and linalool for grape variety, and methanethiol, methional, and homofuraneol for grape maturity.


Subject(s)
Oxygen/analysis , Vitis/chemistry , Wine/analysis , Acetaldehyde/analogs & derivatives , Flavoring Agents/chemistry , Food Handling , Fruit/chemistry , Norisoprenoids/analysis , Pyrones/analysis , Sulfides/analysis , Time Factors
2.
Food Chem ; 309: 125698, 2020 Mar 30.
Article in English | MEDLINE | ID: mdl-31718838

ABSTRACT

Pre-fermentative juice substitution with water or early harvest wine has the potential to produce lower alcohol wines without critically modifying colour or tannin properties and only marginally changing volatile and sensory profiles. Whether this approach is suited to producing lower alcohol wines in the absence of excessive grape ripeness remained to be determined. The current study extends on pre-fermentative approaches to alcohol management under milder grape ripening conditions and builds on an existing study with McLaren Vale Cabernet Sauvignon fruit, allowing for a direct comparison under two distinct vintage conditions. Given its importance to Australia, Shiraz was also included and underwent the same consecutive harvest and juice substitution treatments. Cultivar-dependent implications on wine chemical properties were apparent and declines in wine colour and tannin were particularly evident in Shiraz wines, although impacts on overall wine quality and sensory parameters were minor when adjusting musts within the limit of 13.5 °Baumé.


Subject(s)
Taste/physiology , Vitis/chemistry , Wine/analysis , Adult , Australia , Chromatography, Gel , Color , Female , Fruit/chemistry , Fruit/metabolism , Gas Chromatography-Mass Spectrometry , Humans , Male , Tannins/analysis , Vitis/metabolism , Volatile Organic Compounds/analysis
3.
J Agric Food Chem ; 67(36): 10273-10284, 2019 Sep 11.
Article in English | MEDLINE | ID: mdl-31418566

ABSTRACT

Shiraz wine volatomes from two Australian geographical indications (GIs), that is, Orange and Riverina, were compared using comprehensive two-dimensional gas chromatography coupled to time-of-flight mass spectrometry. Shiraz wines were made in triplicate from grapes harvested at two harvest dates from six vineyards in the two GIs. A total of 133 compounds showed a significant trend between wines from the cooler Orange GI and warmer Riverina. Compounds associated with wines from the cooler climate were grape-derived volatiles, such as monoterpenes, sesquiterpenes, green leaf volatiles, and some norisoprenoids. Fermentation-derived compounds, such as esters and S-containing compounds, showed no specific trend related to grape origin. In addition, wines could be also clearly separated according to the harvest date, irrespective of the climate, with C6 compounds, higher alcohol acetates, and other esters contributing utmost to the differentiation of samples, whereas terpenoids and norisoprenoids did not have an influence. This study demonstrated the plasticity of wine volatome related to grape origin and also the maturity level (harvest date), irrespective of climate.


Subject(s)
Gas Chromatography-Mass Spectrometry/methods , Vitis/chemistry , Volatile Organic Compounds/chemistry , Wine/analysis , Australia , Climate , Discriminant Analysis , Fruit/chemistry , Odorants/analysis , Terpenes/chemistry
4.
Food Chem ; 277: 753-765, 2019 Mar 30.
Article in English | MEDLINE | ID: mdl-30502213

ABSTRACT

The influence of grape maturity on wine volatome was investigated using HS-SPME-GC × GC-TOFMS. Shiraz wines were made from grapes harvested from four different vineyards from two berry maturity levels. A total of 1276 putative compounds were detected in at least one of the wine samples and 175 showed significant trends related to grape maturity. The first two dimensions of the Principal component analysis accounted for 57% of the variation and separated the samples according to the harvest date. Wines from the first harvest date were characterised by an abundance of lipoxygenase derived compounds, norisoprenoids and sulfur-containing compounds whereas a significant increase in some acetate esters was observed in wines produced from the more mature grapes. This study demonstrated a common evolution of grape volatiles for Shiraz inside the same mesoclimate. During the late ripening stage of the grape, a direct nexus between sugar concentration and wine volatile evolution was not observed.


Subject(s)
Gas Chromatography-Mass Spectrometry , Vitis/chemistry , Volatile Organic Compounds/analysis , Wine/analysis , Norisoprenoids/analysis , Norisoprenoids/isolation & purification , Principal Component Analysis , Solid Phase Microextraction , Terpenes/analysis , Terpenes/isolation & purification , Vitis/metabolism , Volatile Organic Compounds/isolation & purification
5.
J Agric Food Chem ; 66(29): 7750-7757, 2018 Jul 25.
Article in English | MEDLINE | ID: mdl-29962206

ABSTRACT

Late-season berry dehydration (LSD) is a common occurrence in Shiraz grapes, particularly those grown in hot climates. LSD results in significant yield reductions; however, the effects on wine composition and sensory characteristics are not well-documented. Wines made of 100% nonshriveled clusters (control) were related to red fruit flavors by the sensory panel, whereas wines made of 80% shriveled clusters (S-VCT) were perceived as more alcoholic and associated with dark fruit and dead/stewed fruit characters. The latter wines also resulted in higher concentrations of massoia lactone and γ-nonalactone, compounds known to contribute to prune and stewed-fruit aromas. Wines made of shriveled grapes were also characterized by an increase in C6-alcohols and a decrease in esters, whereas wine terpenoids were altered compound-specific. An increase in orange pigments and wine chemical age in S-VCT wines indicated faster oxidative aging compared to the control. LSD appeared to alter final wine composition directly but also appeared to influence yeast metabolism, potentially due to an alteration of the composition of lipids in the grape juice. This study emphasized the relevance of sorting shriveled and nonshriveled berries for final wine chemical composition and wine style.


Subject(s)
Vitis/chemistry , Wine/analysis , Adult , Climate , Desiccation , Female , Flavoring Agents/chemistry , Fruit/chemistry , Fruit/growth & development , Humans , Male , Middle Aged , Seasons , Taste , Vitis/growth & development
6.
Food Chem ; 259: 196-206, 2018 Sep 01.
Article in English | MEDLINE | ID: mdl-29680044

ABSTRACT

This study extends previous work on Cabernet Sauvignon wines of lowered alcohol concentrations produced by pre-fermentatively substituting proportions of juice from an overripe crop with "green harvest wine" or water to adjust initial sugar concentrations. Resulting wines were assessed for their volatile compositions and sensory characteristics to evaluate the suitability of this winemaking approach to managing wine alcohol concentrations in warm viticulture regions. Wines from water or green harvest wine substitution were also compared to wines of similar alcohol content produced from earlier harvested grapes. Implementation of water substitution in particular resulted in minor alterations of wine volatile composition compared to the control, and positive aroma and flavour characteristics were preserved. However, overripe sensory attributes such as 'hotness' and 'port wine' were conserved whereas they were absent in wines of similar alcohol level made from earlier harvested grapes, thereby emphasising the relevance of grape (over)maturity when producing lower alcohol wines.


Subject(s)
Vitis/chemistry , Volatile Organic Compounds/analysis , Wine/analysis , Bioreactors , Color , Ethanol/analysis , Fruit/chemistry , Fruit/metabolism , Gas Chromatography-Mass Spectrometry , Principal Component Analysis , Solid Phase Extraction , Taste Perception , Vitis/metabolism , Volatile Organic Compounds/isolation & purification , Water/chemistry
7.
Physiol Plant ; 164(2): 120-133, 2018 Oct.
Article in English | MEDLINE | ID: mdl-29498442

ABSTRACT

Leaves are an important contributor toward berry sugar and nitrogen (N) accumulation, and leaf area, therefore, affects fruit composition during grapevine (Vitis vinifera) berry ripening. The aim of this study was to investigate the impact of leaf presence on key berry quality attributes in conjunction with the accumulation of primary berry metabolites. Shortly after the start of véraison (berry ripening), potted grapevines were defoliated (total defoliation and 25% of the control), and the accumulation of berry soluble solids, N and anthocyanins were compared to that of a full leaf area control. An untargeted approach was undertaken to measure the content in primary metabolites by gas chromatography/mass spectrometry. Partial and full defoliation resulted in reduced berry sugar and anthocyanin accumulation, while total berry N content was unaffected. The juice yeast assimilable N (YAN), however, increased upon partial and full defoliation. Remobilized carbohydrate reserves allowed accumulation of the major berry sugars during the absence of leaf photoassimilation. Berry anthocyanin biosynthesis was strongly inhibited by defoliation, which could relate to the carbon (C) source limitation and/or increased bunch exposure. Arginine accumulation, likely resulting from reserve translocation, contributed to increased YAN upon defoliation. Furthermore, assessing the implications on various products of the shikimate pathway suggests the C flux through this pathway to be largely affected by leaf source limitation during fruit maturation. This study provides a novel investigation of impacts of leaf C and N source presence during berry maturation, on the development of key berry quality parameters as underlined by alterations in primary metabolism.


Subject(s)
Anthocyanins/metabolism , Carbon/metabolism , Fruit/metabolism , Nitrogen/metabolism , Plant Leaves/metabolism , Vitis/metabolism
8.
Physiol Plant ; 161(4): 434-450, 2017 Dec.
Article in English | MEDLINE | ID: mdl-28692131

ABSTRACT

Grapevine (Vitis vinifera) roots and leaves represent major carbohydrate and nitrogen (N) sources, either as recent assimilates, or mobilized from labile or storage pools. This study examined the response of root and leaf primary metabolism following defoliation treatments applied to fruiting vines during ripening. The objective was to link alterations in root and leaf metabolism to carbohydrate and N source functioning under conditions of increased fruit sink demand. Potted grapevine leaf area was adjusted near the start of véraison to 25 primary leaves per vine compared to 100 leaves for the control. An additional group of vines were completely defoliated. Fruit sugar and N content development was assessed, and root and leaf starch and N concentrations determined. An untargeted GC/MS approach was undertaken to evaluate root and leaf primary metabolite concentrations. Partial and full defoliation increased root carbohydrate source contribution towards berry sugar accumulation, evident through starch remobilization. Furthermore, root myo-inositol metabolism played a distinct role during carbohydrate remobilization. Full defoliation induced shikimate pathway derived aromatic amino acid accumulation in roots, while arginine accumulated after full and partial defoliation. Likewise, various leaf amino acids accumulated after partial defoliation. These results suggest elevated root and leaf amino N source activity when leaf N availability is restricted during fruit ripening. Overall, this study provides novel information regarding the impact of leaf source restriction, on metabolic compositions of major carbohydrate and N sources during berry maturation. These results enhance the understanding of source organ carbon and N metabolism during fruit maturation.


Subject(s)
Fruit/metabolism , Plant Roots/metabolism , Vitis/metabolism , Amino Acids/metabolism , Carbohydrate Metabolism/genetics , Carbohydrate Metabolism/physiology , Fruit/physiology , Gas Chromatography-Mass Spectrometry , Plant Leaves/metabolism , Plant Leaves/physiology , Plant Roots/physiology , Vitis/physiology
9.
J Agric Food Chem ; 64(42): 7979-7993, 2016 Oct 26.
Article in English | MEDLINE | ID: mdl-27748118

ABSTRACT

The effect of repetitive controlled oxidation on the chemical and sensory composition of a fresh and fruity style Sauvignon blanc wine was investigated. Chemical analyses were conducted together with extensive sensory profiling. A decrease in volatile thiols responsible for the fruity nuances and an increase in oxidation-related compounds, such as acetaldehyde, during the course of the oxidation was observed. The wine evolved from a fresh and fruity one to one with slight oxidation and then developed extreme oxidative characteristics. The control samples (no oxygen added) developed a "cooked" character that could indicate the formation of "reductive" compounds in these wines. Conversely, the wines that received a single dose of oxygen did not develop this flavor and were perceived to be fresher and fruitier than the control samples. The color of the wine evolved before the disappearance of the pleasant aroma.

10.
J Agric Food Chem ; 64(4): 870-80, 2016 Feb 03.
Article in English | MEDLINE | ID: mdl-26761394

ABSTRACT

Berry shriveling is an often reported occurrence in the Shiraz (Vitis vinifera L.) cultivar. This study investigated the effect of berry shriveling occurring in a high yielding (18.6 ± 1.6 kg/vine) Shiraz vineyard in relation to a temporal investigation of grape and wine composition using three harvest dates. Berry shriveling resulted in delayed total soluble solids and amino acid accumulation into the berry, however differences between treatments diminished or became smaller by the third harvest date. Similarly, ethyl esters of fatty acids and higher alcohol acetates were lower in wines from shriveled berries from the first two harvests; anthocyanins were reduced in wines from shriveled berries at all harvest dates, whereas terpenes were unaltered. Wines made from shriveled berries had higher γ-nonalactone and ß-damascenone concentrations. This study provides novel information on the chemical alterations of grapes and wines made from grapes affected by shriveling.


Subject(s)
Flavoring Agents/chemistry , Vitis/chemistry , Wine/analysis , Amino Acids/chemistry , Amino Acids/metabolism , Flavoring Agents/metabolism , Fruit/chemistry , Fruit/growth & development , Fruit/metabolism , Mass Spectrometry , Vitis/growth & development , Vitis/metabolism
11.
J Sci Food Agric ; 96(3): 915-26, 2016 Feb.
Article in English | MEDLINE | ID: mdl-25752685

ABSTRACT

BACKGROUND: The aim of this study, performed on Sauvignon blanc clones SB11 and SB316, grafted on the same rootstock 101-14 Mgt (Vitis riparia × V. ruperstris) and grown at two adjacent vineyards, was two-fold: (1) to study wine chemical and sensory composition of both clones within an unaltered canopy; and (2) to determine the effect of defoliation (e.g. bunch microclimate) on wine chemical and sensory composition. RESULTS: Orthogonal projection to latent structures discriminate analysis (OPLS-DA) was applied to the concentration profiles of volatile compounds derived from gas chromatography-mass spectrometry data. The loadings directions inferred that 3-isobutyl-2-methoxypyrazine (IBMP) discriminated control treatments (shaded fruit zone) of both clones from defoliation treatments (exposed fruit zone), whereas 3-sulfanyl-hexan-1-ol (3SH), 3-sulfanylhexyl acetate (3SHA), hexanol, hexyl hexanoate and some other esters discriminated defoliated treatments from the controls. The OPLS-DA indicated the importance of IBMP, higher alcohol acetates and phenylethyl esters, for discrimination of clone SB11 from clone SB316 irrespective of the treatment. Defoliation in the fruit zone significantly decreased perceived greenness in clone SB11 and elevated fruitier aromas, whereas in clone SB316 the effect of defoliation on wine sensory perception was less noticeable regardless the decrease in IBMP concentrations. CONCLUSION: These findings highlight the importance of clone selection and bunch microclimate to diversify produced wine styles.


Subject(s)
Vitis/genetics , Volatile Organic Compounds/chemistry , Wine , Food Handling , Gas Chromatography-Mass Spectrometry , Humans , Microclimate , South Africa
12.
Food Chem ; 197 Pt B: 1073-84, 2016 Apr 15.
Article in English | MEDLINE | ID: mdl-26675843

ABSTRACT

This study investigated the potential to improve wine aroma by applying two inactive dry yeast products (IDYs) at the onset of ripening on Sauvignon Blanc grapes. Both products led to increased reduced glutathione concentrations in the grape juice and corresponding wines, as well as differences in individual higher alcohol acetates (HAAs) and ethyl esters of straight chain fatty acids (EEFAs) at the end of fermentation. After two months of storage, a significantly slower decrease of EEFAs and to a lesser extent of HAAs was found for wines made from grapes with IDY applications. These wines also resulted in significantly slower synthesis of ethyl esters of branched acids, whereas varietal thiols were altered in a product-specific manner. The modifications in the wine chemical composition were also sensorially corroborated. This study showed that vineyard additions of IDY products directly on the grapes at the onset of ripening have a subsequent benefit to the production and preservation of aroma in wines.


Subject(s)
Fermentation , Food Handling/methods , Food Quality , Vitis/chemistry , Wine/analysis , Yeast, Dried , Acetates/analysis , Esters/analysis , Saccharomyces cerevisiae , Smell , Sulfhydryl Compounds/analysis
13.
J Agric Food Chem ; 63(41): 9103-11, 2015 Oct 21.
Article in English | MEDLINE | ID: mdl-26434979

ABSTRACT

This work reports the quantitation and sensory characterization of 1,4-cineole in red wine for the first time. A headspace-solid-phase microextraction-gas chromatography-mass spectrometry (HS-SPME-GC-MS) method was developed to quantitate 1,4-cineole and 1,8-cineole in 104 commercial Australian red wines. 1,4-Cineole was detected in all of the wines analyzed, with concentrations ranging from 0.023 to 1.6 µg/L. An important varietal effect was observed, with concentrations of 1,4-cineole in Cabernet Sauvignon wines (mean of 0.6 ± 0.3 µg/L) significantly higher than in Shiraz (0.07 ± 0.04 µg/L) and Pinot Noir (0.2 ± 0.2 µg/L) wines. Regional variations of both cineole isomer concentrations have been measured between wines originating from different Australian regions. Sensory studies demonstrated that the addition of 0.54 µg/L 1,4-cineole in a Cabernet Sauvignon wine, to produce a final concentration of 0.63 µg/L, was perceived significantly by a sensory panel (p < 0.05). Descriptive analyses revealed that 1,4-cineole and 1,8-cineole may contribute to the hay, dried herbs, and blackcurrant aromas reported in Australian Cabernet Sauvignon wines and may be potential markers of regional typicality of these wines.


Subject(s)
Monoterpenes/chemistry , Wine/analysis , Australia , Cyclohexane Monoterpenes , Isomerism , Odorants/analysis , Smell , Taste , Vitis/chemistry
14.
J Agric Food Chem ; 63(18): 4664-72, 2015 May 13.
Article in English | MEDLINE | ID: mdl-25905977

ABSTRACT

The relationship between grape composition and subsequent red wine ester profile was examined. Cabernet Sauvignon and Shiraz, from the same Australian very warm climate vineyard, were harvested at two different stages of maturity and triplicate wines were vinified. Grape analyses focused on nitrogen and lipid composition by measuring 18 amino acids by HPLC-FLD, 3 polyunsaturated fatty acids, and 6 C6-compounds derived from lipid degradation by GC-MS. Twenty esters and four higher alcohols were analyzed in wines by HS-SPME-GC-MS. Concentrations of the ethyl esters of branched acids were significantly affected by grape maturity, but the variations were inconsistent between cultivars. Small relative variations were observed between wines for ethyl esters of fatty acids, whereas higher alcohol acetates displayed the most obvious differences with concentrations ranging from 1.5- to 26-fold higher in Shiraz than in Cabernet Sauvignon wines regardless of the grape maturity. Grape analyses revealed the variations of wine ester composition might be related to specific grape juice nitrogen composition and lipid metabolism. To the authors' knowledge the present study is the first to investigate varietal differences in the ester profiles of Shiraz and Cabernet Sauvignon wines made with grapes harvested at different maturity stages.


Subject(s)
Esters/chemistry , Fruit/chemistry , Vitis/chemistry , Wine/analysis , Climate , Flavoring Agents/chemistry , Fruit/classification , Fruit/growth & development , Vitis/classification , Vitis/growth & development
15.
J Agric Food Chem ; 60(37): 9454-61, 2012 Sep 19.
Article in English | MEDLINE | ID: mdl-22946638

ABSTRACT

Grape berries were classified according to diameter and total soluble solids (TSS) to study the effect of light and temperature on methoxypyrazines (MPs), glutathione (GSH), and hydroxycinnamates (HCAs) during the ripening of Sauvignon blanc. The light exposure of the fruiting zone was modified within leaf and lateral removal at the phenological stage berry of peppercorn size and no removal (control). In comparison to the control, the concentration of 3-isobutyl-2-methoxypyrazine (IBMP) was below the limit of detection in leaf removal 2 weeks before harvest. Leaf removal had no significant influence on GSH and HCAs in the grape juice at harvest. Berry diameter significantly influenced the concentration of IBMP in the grape juice and did not influence the concentration of GSH and HCAs. At harvest, the concentrations of IBMP in grape juices of similar TSS in the control were 12.6 and 5.2 ng/L in 15.5 and 13.5 mm berry diameter classes, respectively. Furthermore, the study showed that berries of the same diameter were not at the same physiological ripening level (not the same TSS).


Subject(s)
Coumaric Acids/analysis , Fruit/classification , Fruit/growth & development , Glutathione/analysis , Pyrazines/analysis , Vitis , Fruit/chemistry , Light , Temperature , Wine
SELECTION OF CITATIONS
SEARCH DETAIL
...