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Georges K Skouroumounis - One of the best experts on this subject based on the ideXlab platform.
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quantitative determination of free and hydrolytically liberated β Damascenone in red grapes and wines using a stable isotope dilution assay
Journal of Chromatography A, 1999Co-Authors: Yorgos Kotseridis, Raymond L Baumes, Georges K SkouroumounisAbstract:Quantitative analysis of free and hydrolytically liberated beta-Damascenone in grapes and wines was developed, using a stable isotope dilution assay. Free beta-Damascenone was isolated from grapes and wines by diethyl ether-hexane (1:1, v/v) extraction and the precursor(s) (glycosidic, polyols) of beta-Damascenone using Sep-Pak Plus C18 RP cartridges. Hydrolytically liberated beta-Damascenone was generated by acid hydrolysis from the precursor(s) extract. Red wines from Bordeaux (Merlot, Cabernet Sauvignon and Cabernet Franc, 1995 and 1996 vintage), Burgundy (Pinot Noir, 1995 and 1996 vintage) regions and Grenache wines from Chateauneuf du Pape and Cotes du Rhone (1995 vintage) were analysed to quantify free beta-Damascenone. The wines made from Grenache and Cabernet Sauvignon (1996 vintage) grapes presented the highest mean amounts of free beta-Damascenone, 5.4 and 5.5 micrograms l-1, respectively. Merlot, Cabernet Sauvignon and Cabernet Franc grapes of Bordeaux (1996 vintage) and their corresponding wines were analysed for quantification of free and hydrolytically liberated beta-Damascenone. The levels of hydrolytically liberated beta-Damascenone in grapes could predict closely the levels of free beta-Damascenone in the corresponding wines after one year of ageing, i.e., almost half the levels found for the grape samples. The influence of enzyme and heat treatment of Merlot wine samples on their beta-Damascenone levels was studied. Heat treatment doubled the levels of this compound, but enzyme treatment generated, in the corresponding wines, half the levels of beta-Damascenone found in the non-enzyme treated wines.
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quantitative determination of free and hydrolytically liberated β Damascenone in red grapes and wines using a stable isotope dilution assay
Journal of Chromatography A, 1999Co-Authors: Yorgos Kotseridis, Raymond L Baumes, Georges K SkouroumounisAbstract:Abstract Quantitative analysis of free and hydrolytically liberated β-Damascenone in grapes and wines was developed, using a stable isotope dilution assay. Free β-Damascenone was isolated from grapes and wines by diethyl ether–hexane (1:1, v/v) extraction and the precursor(s) (glycosidic, polyols) of β-Damascenone using Sep-Pak Plus C18 RP cartridges. Hydrolytically liberated β-Damascenone was generated by acid hydrolysis from the precursor(s) extract. Red wines from Bordeaux (Merlot, Cabernet Sauvignon and Cabernet Franc, 1995 and 1996 vintage), Burgundy (Pinot Noir, 1995 and 1996 vintage) regions and Grenache wines from Chateauneuf du Pape and Cotes du Rhone (1995 vintage) were analysed to quantify free β-Damascenone. The wines made from Grenache and Cabernet Sauvignon (1996 vintage) grapes presented the highest mean amounts of free β-Damascenone, 5.4 and 5.5 μg l−1, respectively. Merlot, Cabernet Sauvignon and Cabernet Franc grapes of Bordeaux (1996 vintage) and their corresponding wines were analysed for quantification of free and hydrolytically liberated β-Damascenone. The levels of hydrolytically liberated β-Damascenone in grapes could predict closely the levels of free β-Damascenone in the corresponding wines after one year of ageing, i.e., almost half the levels found for the grape samples. The influence of enzyme and heat treatment of Merlot wine samples on their β-Damascenone levels was studied. Heat treatment doubled the levels of this compound, but enzyme treatment generated, in the corresponding wines, half the levels of β-Damascenone found in the non-enzyme treated wines.
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synthesis of labelled 2h4 β Damascenone 2h2 2 methoxy 3 isobutylpyrazine 2h3 α ionone and 2h3 β ionone for quantification in grapes juices and wines
Journal of Chromatography A, 1998Co-Authors: Yorgos Kotseridis, Raymond L Baumes, Georges K SkouroumounisAbstract:Abstract The syntheses of four isotopically labelled aroma compounds, [ 2 H 4 ]β-Damascenone, [ 2 H 2 ]2-methoxy-3-isobutylpyrazine, [ 2 H 3 ]α-ionone, and [ 2 H 3 ]β-ionone, whose natural analogues are commonly found in grapes and wines, have each been achieved in a one step reaction. These compounds were used to establish analytical procedures to quantify the natural analogues in grape juices and wines, by gas chromatography–mass spectroscopy. The concentration of β-Damascenone, 2-methoxy-3-isobutylpyrazine, α-ionone and β-ionone in a 1996 St-Emilion Merlot wine was, 2.9 μg l −1 , 11.4 ng l −1 , 27.9 ng l −1 and 84.1 ng l −1 respectively, with a coefficient of variance below 5% for each analyte.
Mark A Sefton - One of the best experts on this subject based on the ideXlab platform.
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occurrence sensory impact formation and fate of Damascenone in grapes wines and other foods and beverages
Journal of Agricultural and Food Chemistry, 2011Co-Authors: Mark A Sefton, George K Skouroumounis, Gordon M Elsey, Dennis K TaylorAbstract:Among plant-derived odorants, Damascenone is one of the most ubiquitous, sometimes occurring as an apparent natural product but more commonly occurring in processed foodstuffs and beverages. It has been widely reported as a component of alcoholic beverages, particularly of wines made from the grape Vitis vinifera. Although Damascenone has one of the lowest ortho- and retronasal detection thresholds of any odorant, its contribution to the sensory properties of most products remains poorly understood. Damascenone can be formed by acid-catalyzed hydrolyses of plant-derived apocarotenoids, in both aglycon and glycoconjugated forms. These reactions can account for the formation of Damascenone in some, but not all, products. In wine, Damascenone can also be subject to degradation processes, particularly by reaction with sulfur dioxide.
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formation of Damascenone under both commercial and model fermentation conditions
Journal of Agricultural and Food Chemistry, 2011Co-Authors: Natoiya D R Lloyd, Maurizio Ugliano, Mark A Sefton, George K Skouroumounis, Dennis K Taylor, Dimitra L Capone, Gordon M ElseyAbstract:The fermentations, at a commercial winery, of six different grape musts encompassing the varieties Riesling, Chardonnay, Sauvignon blanc, Shiraz, Grenache, and Pinot noir were monitored for Damascenone concentration. In every case, the concentration of Damascenone increased during fermentation from low or undetectable levels to concentrations of several parts per billion. Further increases in Damascenone concentration were observed during barrel aging of three of these wines. Two ketones, megastigma-4,6,7-triene-3,9-dione (4) and 3-hydroxymegastigma-4,6,7-trien-9-one (5), were synthesized and subjected to fermentation conditions using two yeasts, AWRI 796, and AWRI 1537. In the case of the former compound, 4, synthesis confirmed the original, tentative assignment of the structure and confirmed 4 as a natural product, isolated from honey. Both compounds, under the action of both yeasts, produced appreciable amounts of Damascenone (1), with ketone 5 and AWRI 796 yeast yielding the highest concentration of 1.
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rationalizing the formation of Damascenone synthesis and hydrolysis of Damascenone precursors and their analogues in both aglycone and glycoconjugate forms
Journal of Agricultural and Food Chemistry, 2008Co-Authors: Merran A Daniel, Gordon M Elsey, Dimitra L Capone, Carolyn J Puglisi, Mark A SeftonAbstract:Storage of megastigma-4,6,7-trien-3,9-diol (5), and megastigma-3,4-dien-7-yn-9-ol (6) in aqueous ethanol solution at pH 3.0 and 3.2 gave exclusively Damascenone (1) and Damascenone adducts at room temperature. The diol (5) had half-lives for the conversion of 32 and 48 h at pH 3.0 and pH 3.2, respectively. The acetylenic alcohol (6) had half-lives of 40 and 65 h at the same pH levels. In order to study the reactivity of the C-9 hydroxyl function in 5 and in the previously investigated allenic triol 2, two model compounds, megastigma-4,6,7-trien-9-ol (7) and megastigma-6,7-dien-9-ol (8) were synthesized. No 1,3-transposition of oxygen to form analogues of Damascenone was observed when 7 and 8 were subjected to mild acidic conditions. Such transposition takes place only with highly conjugated acetylenic precursors such as 6 or tertiary allenic alcohols such as 2. The placement of glucose at C-3 of 5 and at C-9 of 6 gave the glycosides 9 and 10, respectively. The effect of such glucoconjugation was to increase the observed half-lives by a factor of only 1.6-1.7 for the allenic glucoside 9, and by 2.1-2.2 for the acetylenic glucoside 10. These studies indicate that the effect of glycosylation on Damascenone formation is probably not important on the time scale of wine making and maturation.
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the consumption of Damascenone during early wine maturation
Developments in food science, 2006Co-Authors: Mark A Sefton, Gordon M Elsey, Merran A Daniel, Michael V PerkinsAbstract:Damascenone has been shown to undergo reaction with common wine components. Following the action of acid and heat alone, two bicyclic compounds were isolated. Two C9 adducts, resulting from the addition of water and ethanol were also observed. Their formation was shown to be reversible. When treated with SO2 (introduced as its aqueous equivalent, bisulfite) the concentration of Damascenone rapidly decreased to zero. A C9 sulfonic acid derivative was isolated and characterised, and its formation from Damascenone shown to be irreversible in the presence of acetaldehyde.
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precursors to Damascenone synthesis and hydrolysis of isomeric 3 9 dihydroxymegastigma 4 6 7 trienes
Journal of Agricultural and Food Chemistry, 2005Co-Authors: Carolyn J Puglisi, Gordon M Elsey, Merran A Daniel, Dimitra L Capone, Rolf H Prager, Mark A SeftonAbstract:A series of four isomeric 3,9-dihydroxymegastigma-4,6,7-trienes, 8, has been prepared. The (3S,6R,9S) isomer of 8 proved to be identical to an isomer of this compound tentatively identified as an intermediate in the formation of Damascenone from an allene triol. Each of the four isomers, when hydrolyzed independently of each other at pH 3.0 and 25 °C, produced product mixtures in which the major product was Damascenone (1). Contrary to expectation, 3-hydroxydamascone (5) was not observed in any of the hydrolyses. Consequently, the mechanism of formation of Damascenone proposed earlier requires modification. In each hydrolysis, the product mixtures showed the presence of a second isomer of 8, produced by epimerization during hydrolysis. Chiral analysis on a Cyclosil B column revealed that this epimerization was occurring at C3 in each of the hydrolyses. Keywords: Damascenone; flavor precursors; wine; carotenoid metabolites; epimerization; acid hydrolysis
Peter Schieberle - One of the best experts on this subject based on the ideXlab platform.
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characterization of the key aroma compounds in bartlett pear brandies by means of the sensomics concept
Journal of Agricultural and Food Chemistry, 2013Co-Authors: Bianca Willner, Michael Granvogl, Peter SchieberleAbstract:The aroma compounds in two commercial Bartlett pear brandies clearly differing in their overall aroma profiles were detected in the volatile fractions by the aroma extract dilution analysis. In brandy A eliciting the more intense pear-like, fruity aroma, ethyl (S)-2-methylbutanoate, (E)-β-Damascenone, 1,1-diethoxyethane, 2- and 3-methylbutanol, (S)-2- and 3-methylbutanoic acid, and 2-phenylethanol were found with the highest Flavor Dilution (FD) factors. In brandy B judged to have a weaker overall aroma, also (E)-β-Damascenone, ethyl (S)-2-methylbutanoate, and 2-phenylethanol revealed high FD factors, while many odorants showed lower FD factors. Fourty-four odor-active compounds were quantitated by stable isotope dilution assays, and the odor activity values (OAVs; ratio of concentrations to odor thresholds) confirmed (E)-β-Damascenone and ethyl (S)-2-methylbutanoate as important aroma compounds in brandy A, while the OAVs of most odorants were much lower in brandy B. By aroma recombination studies, the a...
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characterization of the key aroma compounds in rape honey by means of the molecular sensory science concept
Journal of Agricultural and Food Chemistry, 2012Co-Authors: Brigitte Ruisinger, Peter SchieberleAbstract:By application of aroma extract dilution analysis (AEDA) on the volatile fraction isolated by solvent extraction and solvent-assisted flavor evaporation (SAFE) from unifloral rape honey harvested in July 2009, 28 odor-active areas could be detected within a flavor dilution factor (FD) range of 4–2048. The highest FD factors were found for (E)-β-Damascenone (cooked apple-like), phenylacetic acid (honey-like), 4-methoxybenzaldehyde (aniseed-like), 3-phenylpropanoic acid (flowery, waxy), and 2-methoxy-4-vinylphenol (clove-like). Twenty-three odorants were then quantitated by application of stable isotope dilution assays, and their odor activity values (OAV, ratio of concentration to odor threshold) were calculated on the basis of newly determined odor thresholds in an aqueous fructose–glucose solution. The highest OAVs were calculated for (E)-β-Damascenone, 3-phenylpropanoic acid, phenylacetic acid, dimethyl trisulfide, and phenylacetaldehyde. Quantitative measurements on a rape honey produced in 2011 confir...
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identification based on quantitative measurements and aroma recombination of the character impact odorants in a bavarian pilsner type beer
Journal of Agricultural and Food Chemistry, 2005Co-Authors: Helge T Fritsch, Peter SchieberleAbstract:Application of aroma extract dilution analysis on the volatiles isolated from a Bavarian Pilsner-type beer revealed 40 odor-active constituents in the flavor dilution (FD) factor range of 16−2048, among which ethyl octanoate, (E)-β-Damascenone, 2- and 3-methylbutanoic acid, and 4-hydroxy-2,5-dimethyl-3(2H)-furanone showed the highest FD factor of 2048. After quantitation of the 26 odorants showing FD factors ≥128 by stable isotope dilution analysis and determination of their odor thresholds in water, odor acitivity values (OAVs) were calculated. The results indicated ethanol, (E)-β-Damascenone, (R)-linalool, acetaldehyde, and ethyl butanoate with the highest OAVs, followed by ethyl 2-methylpropanoate and ethyl 4-methylpentanoate, which was previously unknown in beer. Finally, the overall aroma of the beer could be mimicked for the first time by recombining 22 reference odorants in the same concentrations as they occurred in the beer using ethanol/water as the matrix. Keywords: Beer; aroma; aroma extract d...
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analysis of the seasoning like flavour substances of a commercial lovage extract levisticum officinale koch
Flavour and Fragrance Journal, 1993Co-Authors: Imre Blank, Peter SchieberleAbstract:identified as 3-hydroxy-4,5-dimethyl-2(5H)-furanone (sotolon), (E)-p-Damascenone, 2-ethyl-4-hydroxy-5-methyl3-(2H)-furanone, 4-hydroxy-2,5-dimethyl-3(2H)-furanone, 3-methylbutanoic acid, and acetic acid. These odorants have not yet been reported in the literature as components of lovage. Sotolon was the key aroma compound of the acidic fraction of lovage extract due t o its characteristic seasoning-like flavour and high flavour dilution factor. The concentration of sotolon was determined by a stable isotope dilution assay.
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quantitative determination of beta Damascenone in foods using a stable isotope dilution assay
Journal of Agricultural and Food Chemistry, 1991Co-Authors: A. Sen, Peter Schieberle, Gudrun Laskawy, Werner GroschAbstract:The aim was to develop such an assay for β-Damascenone and to apply it for the analysis of roasted coffee (powder and brew), black tea, honey and beer samples.
Yorgos Kotseridis - One of the best experts on this subject based on the ideXlab platform.
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quantitative determination of free and hydrolytically liberated β Damascenone in red grapes and wines using a stable isotope dilution assay
Journal of Chromatography A, 1999Co-Authors: Yorgos Kotseridis, Raymond L Baumes, Georges K SkouroumounisAbstract:Quantitative analysis of free and hydrolytically liberated beta-Damascenone in grapes and wines was developed, using a stable isotope dilution assay. Free beta-Damascenone was isolated from grapes and wines by diethyl ether-hexane (1:1, v/v) extraction and the precursor(s) (glycosidic, polyols) of beta-Damascenone using Sep-Pak Plus C18 RP cartridges. Hydrolytically liberated beta-Damascenone was generated by acid hydrolysis from the precursor(s) extract. Red wines from Bordeaux (Merlot, Cabernet Sauvignon and Cabernet Franc, 1995 and 1996 vintage), Burgundy (Pinot Noir, 1995 and 1996 vintage) regions and Grenache wines from Chateauneuf du Pape and Cotes du Rhone (1995 vintage) were analysed to quantify free beta-Damascenone. The wines made from Grenache and Cabernet Sauvignon (1996 vintage) grapes presented the highest mean amounts of free beta-Damascenone, 5.4 and 5.5 micrograms l-1, respectively. Merlot, Cabernet Sauvignon and Cabernet Franc grapes of Bordeaux (1996 vintage) and their corresponding wines were analysed for quantification of free and hydrolytically liberated beta-Damascenone. The levels of hydrolytically liberated beta-Damascenone in grapes could predict closely the levels of free beta-Damascenone in the corresponding wines after one year of ageing, i.e., almost half the levels found for the grape samples. The influence of enzyme and heat treatment of Merlot wine samples on their beta-Damascenone levels was studied. Heat treatment doubled the levels of this compound, but enzyme treatment generated, in the corresponding wines, half the levels of beta-Damascenone found in the non-enzyme treated wines.
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quantitative determination of free and hydrolytically liberated β Damascenone in red grapes and wines using a stable isotope dilution assay
Journal of Chromatography A, 1999Co-Authors: Yorgos Kotseridis, Raymond L Baumes, Georges K SkouroumounisAbstract:Abstract Quantitative analysis of free and hydrolytically liberated β-Damascenone in grapes and wines was developed, using a stable isotope dilution assay. Free β-Damascenone was isolated from grapes and wines by diethyl ether–hexane (1:1, v/v) extraction and the precursor(s) (glycosidic, polyols) of β-Damascenone using Sep-Pak Plus C18 RP cartridges. Hydrolytically liberated β-Damascenone was generated by acid hydrolysis from the precursor(s) extract. Red wines from Bordeaux (Merlot, Cabernet Sauvignon and Cabernet Franc, 1995 and 1996 vintage), Burgundy (Pinot Noir, 1995 and 1996 vintage) regions and Grenache wines from Chateauneuf du Pape and Cotes du Rhone (1995 vintage) were analysed to quantify free β-Damascenone. The wines made from Grenache and Cabernet Sauvignon (1996 vintage) grapes presented the highest mean amounts of free β-Damascenone, 5.4 and 5.5 μg l−1, respectively. Merlot, Cabernet Sauvignon and Cabernet Franc grapes of Bordeaux (1996 vintage) and their corresponding wines were analysed for quantification of free and hydrolytically liberated β-Damascenone. The levels of hydrolytically liberated β-Damascenone in grapes could predict closely the levels of free β-Damascenone in the corresponding wines after one year of ageing, i.e., almost half the levels found for the grape samples. The influence of enzyme and heat treatment of Merlot wine samples on their β-Damascenone levels was studied. Heat treatment doubled the levels of this compound, but enzyme treatment generated, in the corresponding wines, half the levels of β-Damascenone found in the non-enzyme treated wines.
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synthesis of labelled 2h4 β Damascenone 2h2 2 methoxy 3 isobutylpyrazine 2h3 α ionone and 2h3 β ionone for quantification in grapes juices and wines
Journal of Chromatography A, 1998Co-Authors: Yorgos Kotseridis, Raymond L Baumes, Georges K SkouroumounisAbstract:Abstract The syntheses of four isotopically labelled aroma compounds, [ 2 H 4 ]β-Damascenone, [ 2 H 2 ]2-methoxy-3-isobutylpyrazine, [ 2 H 3 ]α-ionone, and [ 2 H 3 ]β-ionone, whose natural analogues are commonly found in grapes and wines, have each been achieved in a one step reaction. These compounds were used to establish analytical procedures to quantify the natural analogues in grape juices and wines, by gas chromatography–mass spectroscopy. The concentration of β-Damascenone, 2-methoxy-3-isobutylpyrazine, α-ionone and β-ionone in a 1996 St-Emilion Merlot wine was, 2.9 μg l −1 , 11.4 ng l −1 , 27.9 ng l −1 and 84.1 ng l −1 respectively, with a coefficient of variance below 5% for each analyte.
Russell L. Rouseff - One of the best experts on this subject based on the ideXlab platform.
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quantification of β Damascenone in orange juice using headspace standard addition spme with selected ion gc ms
Analytical Methods, 2013Co-Authors: Kanjana Mahattanatawee, Kevin L Goodner, Russell L. RouseffAbstract:An analytical procedure to quantify concentrations of β-Damascenone in orange juice was developed using static headspace SPME with selected ion GC-MS at m/z 190. Standard additions at four levels of β-Damascenone (0.5 to 2 μg L−1) were used to establish the regression equation used to quantify juice samples. Reproducibility in terms of relative standard deviation values at each level ranged from 1% to 15%. Orange juice β-Damascenone concentrations increased with increased heat treatment from 0.15 μg L−1 in the raw juice to 0.3 μg L−1 in juice which had been heated to 90 °C for 25 s. Levels of β-Damascenone were determine in three types of commercial orange juice which have different levels of heat treatment. β-Damascenone concentrations ranged from 0.122 to 0.281 μg L−1 in not from concentrate, NFC, juice (heated once), 0.117 to 0.445 μg L−1 in frozen concentrated orange juice, FCOJ, and 0.221 to 0.690 μg L−1 in reconstituted from concentrate, RFC, (heated to remove water and heated again after water restored). Although levels of β-Damascenone increase with heat treatment, the wide range of β-Damascenone concentrations observed would make it inappropriate to use as a single indicator of heat treatment. This is the first time β-Damascenone has been quantified by headspace SPME in different types of orange juice samples.
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comparison of aroma volatiles in commercial merlot and cabernet sauvignon wines using gas chromatography olfactometry and gas chromatography mass spectrometry
Journal of Agricultural and Food Chemistry, 2006Co-Authors: Ozan Gurbuz, June Rouseff, Russell L. RouseffAbstract:Seventy-four aroma active compounds were observed in Merlot and Cabernet Sauvignon wines produced in California and Australia. Volatiles were sampled using solid phase microextraction and analyzed using time-intensity gas chromatography−olfactometry and gas chromatography−mass spectrometry (GC-MS). The most intense odorants were 3-methyl-1-butanol, 3-hydroxy-2-butanone, octanal, ethyl hexanoate, ethyl 2-methylbutanoate, β-Damascenone, 2-methoxyphenol, 4-ethenyl-2-methoxy-phenol, ethyl 3-methylbutanoate, acetic acid, and 2-phenylethanol. Aroma compounds were classified according to their aroma descriptor similarity and summed into nine distinct categories consisting of fruity, sulfury, caramel/cooked, spicy/peppery, floral, earthy, pungent/chemical, woody, and green/vegetative/fatty. Both Merlot and Cabernet Sauvignon wines were characterized by high fruity, caramel, green, and earthy aroma totals. Although there were distinct quantitative differences between Merlot and Cabernet wines, the relative aroma c...
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thermal oxidation of 9 cis neoxanthin in a model system containing peroxyacetic acid leads to the potent odorant β Damascenone
Journal of Agricultural and Food Chemistry, 2005Co-Authors: Yair Bezman, Russell L. Rouseff, Susanne Baldermann, Itzhak Bilkis, Peter Winterhalter, Peter Fleischmann, Michael NaimAbstract:The potent odorant β-Damascenone was formed directly from 9‘-cis-neoxanthin in a model system by peroxyacetic acid oxidation and two-phase thermal degradation without the involvement of enzymatic activity. β-Damascenone formation was heavily dependent on pH (optimum at 5.0) and temperature, occurring over the two sequential phases. The first was incubation with peroxyacetic acid at 60 °C for 90 min, and the second was at above 90 °C for 20 min. Only traces of β-Damascenone were formed on application of only one of the two phases. Formate and citrate solutions produced a much better environment for β-Damascenone formation than acetate and phosphate. About 7 μg/L β-Damascenone was formed from 5.8 mg/L 9‘-cis-neoxanthin under optimal experimental condition. The detailed pathway by which β-Damascenone is formed remains to be elucidated. Keywords: β-Damascenone; 9‘-cis-neoxanthin; peroxyacetic acid; epoxide; thermolysis
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2 methyl 3 furanthiol and methional are possible off flavors in stored orange juice aroma similarity nif snif gc o and gc analyses
Journal of Agricultural and Food Chemistry, 2001Co-Authors: Yair Bezman, Russell L. Rouseff, Michael NaimAbstract:The occurrence of methional in fresh orange juice, and possible occurrence of β-Damascenone in heated orange juice, has been previously suggested. Here we report on the occurrence of 2-methyl-3-furanthiol in the headspace, collected by solid-phase micro-extraction, of fresh, pasteurized, and stored orange juice. The contents of 2-methyl-3-furanthiol and methional were quantified, and the relative level of β-Damascenone was estimated, in the headspace of fresh, pasteurized, and stored orange juices using the nasal impact frequency (NIF) and surface of NIF (SNIF) GC−Olfactometry procedure. 2-Methyl-3-furanthiol concentrations were 2 ng/L in fresh and pasteurized Shamuti orange juice, and 270 ng/L in stored juice of the same variety. Methional concentrations were 550, 830, and 11550 ng/L in fresh, pasteurized, and stored pasteurized juices, respectively. β-Damascenone content appeared to have increased during pasteurization and storage. Aroma-similarity experiments strongly suggest that 2-methyl-3-furanthiol...
