Damascenone

Modulating analytical characteristics of thermovinified Carignan musts and the volatile composition of the resulting wines through the heating temperature.[Pubmed:29622232]

Food Chem. 2018 Aug 15;257:7-14.

The impact of two temperature levels (50 degrees C and 75 degrees C) and heating times (30min and 3h) on the composition of thermovinified musts and wines from Carignan was investigated at the laboratory scale in 2014 and 2015. The heating temperature had a significant impact on the extraction of amino acids and a probable thermal degradation of anthocyanins was noted at 75 degrees C. In 2014, musts from grapes that underwent a heat treatment at 50 degrees C for 3h had a similar level of phenolic compounds as those treated at 75 degrees C for 30min. This indicates that the reduction of the heating temperature in some vintages can be compensated for through an extension of the heating period. Several grape-derived molecules were impacted by the rise in temperature and wines made from grapes treated at 50 degrees C in most cases contained larger concentrations of geraniol, beta-citronellol, beta-Damascenone and 3-mercaptohexanol.

Assessment of oxidation compounds in oaked Chardonnay wines: A GC-MS and (1)H NMR metabolomics approach.[Pubmed:29622187]

Food Chem. 2018 Aug 15;257:120-127.

The oxidation of oaked Chardonnay wine during long-term storage was studied by headspace solid-phase microextraction coupled to gas chromatography-mass spectrometry (HS-SPME-GC/MS) and proton ((1)H) nuclear magnetic resonance (NMR) spectroscopy. Three distinct groups of wine were defined based on the browning index: control, least oxidized (OX1) and most oxidized (OX2). HS-SPME-GC/MS and (1)H NMR spectroscopy enabled the profiling of a total of 155 compounds in all wine samples including aldehydes, ketones, esters, polyphenols, among other classes. Acetaldehyde, 3-methylbutanal, 2-phenylacetaldehyde, methional, 3-penten-2-one, beta-Damascenone and four unknown carbonyl compounds showed the highest percentage of variation with oxidation. Novel oxidation markers found in this work include pentanal, 3-methyl-2-butanone, 3-penten-2-one, 2-methyltetrahydrofuran-3-one, beta-Damascenone, ethyl 2-methylbutanoate and vinyl decanoate. In addition, several correlations between polyphenols, aroma compounds and absorbance at 420nm (A420) were observed, suggesting the occurrence of chemical reactions with a possible impact in wine browning.

Volatile profile of elderberry juice: Effect of lactic acid fermentation using L. plantarum, L. rhamnosus and L. casei strains.[Pubmed:29433231]

Food Res Int. 2018 Mar;105:412-422.

In this study we explored, for the first time, the lactic acid fermentation of elderberry juice (EJ). A total of 15 strains isolated from dairy and plant matrices, belonging to L. plantarum, L. rhamnosus and L. casei, were used for fermentations. The volatile profile of started and unstarted EJ was characterized by HS-SPME/GC-MS technique after 48h of fermentation and 12days of storage at 4 degrees C. All L. plantarum and L. rhamnosus strains exhibited a good capacity of growth while not all L. casei strains showed the same ability. The aromatic profile of fermented juices was characterized by the presence of 82 volatile compounds pertaining to different classes: alcohols, terpenes and norisoprenoids, organic acids, ketones and esters. Elderberry juice fermented with L. plantarum strains showed an increase of total volatile compounds after 48h while the juices fermented with L. rhamnosus and L. casei exhibited a larger increase after the storage. The highest concentration of total volatile compounds were observed in EJ fermented with L. plantarum 285 isolated from dairy product. Ketones increased in all fermented juices both after fermentation and storage and the most concentrated were acetoin and diacetyl. The organic acids were also affected by lactic acid fermentation and the most abundant acids detected in fermented juices were acetic acid and isovaleric acid. Hexanol, 3-hexen-1-ol (Z) and 2-hexen-1-ol (E) were positively influenced during dairy lactic acid bacteria strains fermentation. The most represented esters were ethyl acetate, methyl isovalerate, isoamyl isovalerate and methyl salicylate, all correlated with fruit notes. Among terpenes and norisoprenoids, beta-Damascenone resulted the main representative with its typical note of elderberry. Furthermore, coupling obtained data with multivariate statistical analyses, as Principal Component Analysis (PCA) and Classification Trees (CT), it was possible to relate the characteristic volatile profile of samples with the different species and strains applied in this study.

Norisoprenoids, Sesquiterpenes and Terpenoids Content of Valpolicella Wines During Aging: Investigating Aroma Potential in Relationship to Evolution of Tobacco and Balsamic Aroma in Aged Wine.[Pubmed:29616214]

Front Chem. 2018 Mar 19;6:66.

During wine aging, tobacco and balsamic aroma notes appear. In this paper, volatile compounds directly or potentially related to those aromas have been investigated in Corvina and Corvinone wines during aging. Corvina and Corvinone are two northern-Italy autochthonous red grape varieties, used to produce Valpolicella Classico and Amarone wines, both characterized by tobacco and balsamic aroma notes. Wines were analyzed shortly after bottling or following model aging at 60 degrees C for 48, 72, and 168 h. Volatile compounds were analyzed by HS-SPME-GC-MS. Results showed that compounds related to tobacco aroma [beta-Damascenone, 3-oxo-alpha-ionol, (E)-1-(2,3,6-Trimethylphenyl)-buta-1,3-diene (TPB), and megastigmatrienones] increased in relationship to storage time with different patterns. beta-Damascenone and 3-oxo-alpha-ionol rapidly increased to reach a plateau in the first 48-72 h of model aging. Instead, TPB and megastigmatrienones concentration showed a linear correlation with aging time. During model aging, several cyclic terpenes tended to increase. Among them 1,8-cineole and 1,4-cineole, previously reported to contribute to red wine eucalyptus notes increased proportionally to storage time, and this behavior was clearly associated with reactions involving alpha-terpineol, limonene, and terpinolene, as confirmed by studies with model wine solutions. Among other relevant volatile compounds, sesquiterpenes appear to contribute potentially balsamic and spicy aroma notes. In this study, linear sesquiterpenes (nerolidol, farnesol) underwent acid hydrolysis during long wine aging, while cyclic sesquiterpenes seemed to increase with time. The chemical pathways associated with evolution of some of the compounds investigated have been studied in model wine.

Changes of free-form volatile compounds in pre-treated raisins with different packaging materials during storage.[Pubmed:29580531]

Food Res Int. 2018 May;107:649-659.

The aroma profiles of volatile compounds (VOCs) were analyzed by GC/MS in pre-treated air-dried (PAD) and sun-dried (PSD) raisins during storage. Total 98, 94 and 81 VOCs were identified in Zixiang Seedless raisins (ZSRs), Centennial Seedless raisins (CSRs) and Thompson Seedless raisins (TSRs), respectively. During storage, the overall concentrations of VOCs of PSD raisins were higher in plastic bag (PB) compared to those in woven bag (WB). Regarding fruity and floral aromas, the effect of PAD and PB was significant throughout the storage periods (3, 6 and 9months), however, fatty aroma was higher in PSD raisins due to the major contribution of 2,3-butanedione. The main fruity and floral aroma contributors were beta-Damascenone, limonene, rose oxide, geraniol and ethyl hexanoate. This study showed that compounds came from unsaturated fatty acid oxidation, glycosidically-derived and grape-derived source were contributed to fruity, floral or herbaceous aromas, but Maillard reaction-derived VOCs imparted fatty and roasted aromas.

Effects of Basal Defoliation on Wine Aromas: A Meta-Analysis.[Pubmed:29597302]

Molecules. 2018 Mar 28;23(4). pii: molecules23040779.

Basal defoliation, as one of the most common viticulture management practices to modify fruit zone microclimates, has been widely applied aiming at improving wine quality. Wine aroma contributes greatly to wine quality, yet the effects of basal defoliation on wine aromas show discrepancies according to previous studies. This study is a meta-analysis performed to dissect the factors related to the influence of basal defoliation on volatile compounds in wine. Timing of basal defoliation plays an important role in the concentration of varietal aromas in wine. Pre-veraison defoliation induces an increase in beta-Damascenone and linalool as well as a reduction in 3-isobutyl-2-methoxypyrazine (IBMP). The effects of basal defoliation on certain volatile compounds relative to fermentation aromas in wine (1-hexanol, beta-phenylethanol, 2-phenylethyl acetate, decanoic acid, and ethyl octanoate) depend on grape maturity. There are also other factors, such as cultivar and climate conditions, that might be responsible for the effect of basal defoliation on wine aromas. The concentrations of isobutanol, isoamyl alcohol, hexanoic acid, and octanoic acid as well as ethyl isobutyrate, ethyl hexanoate, ethyl isovalerate, and ethyl decanoate in wine are not markedly affected by basal defoliation. Due to limited studies included in this meta-analysis, more trials are needed to confirm the current findings.