Analysis of volatile compounds of pineapple wine using solid-phase microextraction techniques

A headspace solid-phase microextraction (HS-SPME) method coupled with gas chromatography-mass spectrometry (GC-MS) was applied for the qualitative or semiquantitative characterization of brandy volatiles. SPME variables (SPME fiber, extraction temperature and time, and ethanol concentration) were optimized. A total of 144 compounds were from the brandies' volatiles, tentatively identified or identified by comparing mass spectra and retention indices of the standards or from literature. Of these, 57 are common to 11 brandies. They were mainly represented by esters and alcohols, such as 2-methyl propanol, 3-methyl butanol, 1-hexanol, ethyl octanoate, and ethyl decanoate, which were quantitatively determined. Chromatographic peaks were integrated using selective ion method (SIM) and the semiquantitative data analyzed using principal component analysis (PCA) and cluster analysis (CA) to study relationships between volatile composition and brandy. Eleven brandies were differentiated into 3 groups: 1 for Hennessy VSOP and XO samples, 1 for Changyu PEGASE VSOP and XO-1, 2, 3 samples, and the other for Changyu PEGASE brandy and VO, Taro brandy, Baiyang River brandy, and Wealth XO samples. The classification of groups is consistent with the brandy samples by variety and grade.

ABSTRACT: The main sensory contribution of each post‐fermentation production stage of muscat wine distillates can be tracked by following the concentration of just 1 corresponding chemical marker. Matching sample clusters of sensory and chemical data by using principal components analysis (PCA) revealed potential chemical markers. The data used in this study correspond to 12 sensory attributes that showed significant differences among products ( P < 0.05) and concentrations of 23 volatile compounds of 14 distillate fractions and 15 finished Piscos. Artificial fruit attribute, characteristic of the head fraction (FR1) can be tracked with esters. Linalool, main odor attribute of the 1st part of the heart (FR2) can be tracked with linalool molecule. The 2nd part of the heart (FR3) can be tracked with octanoic acid, decanoic acid, furfural and ethyl lactate, accounting for tails attribute. In blended and aged finished products, chemical markers accounting for the effects of distillate fractions were similar but not identical to the markers from samples obtained from the purely distilled samples. Chemical markers for FR1 are ethyl hexanoate, ethyl octanoate, ethyl decanoate. Differentiation between FR1 and FR2 is less evident than in the purely distilled samples due to the linalool and artificial fruit attribute correlation. Chemical markers for FR2, therefore, include linalool and esters ethyl hexanoate, ethyl octanoate, and ethyl decanoate. The blending of the 2nd part of the heart (FR3) can be tracked with 2‐phenylethanol, ethyl lactate, and decanoic acid. Oak aging was tracked with eugenol and whisky lactones, while 5‐hydroxy‐methyl‐2‐furfural accounted for added caramel.

The aim of this work was to investigate the volatile compositions of four Chinese functional liquors. For this purpose, volatile compounds of four liquors were extracted with head-space solid-phase microextraction (HS-SPME) and analyzed with gas chromatography-mass spectrometry (GC-MS) along with the determination of odor activity value (OAV) and relative odor contribution (ROC). Sixty volatiles were tentatively identified and categorized into the following seven groups: alcohols, esters, fatty acids, carbonyl compound, hydrocarbons, phenols, and other components. The differences in chemical composition of volatile compounds were visualized with heat maps. Odorants were compared with different samples using a statistical analysis of Venn diagrams and a multivariate principal component analysis, and ethyl hexanoate, ethyl acetate, and ethyl octanoate were found to be the key odorants. Besides, abundant phenolic contents and high antioxidant ability of four Chinese functional liquors could potentially bring better health-boosting effects.

Chardonnay marc, consisting of grape skins, seeds, and stems, is a coproduct of grape juice production for Chardonnay wine making. The discovery that marc contains a rich source of health-promoting molecules has led to its growing popularity as a flavorful healthy food ingredient. However, the odorants responsible for its pleasant fruity aroma remain unknown. In this study, 35 odorants were identified in Chardonnay marc skins using solvent-assisted flavor evaporation (SAFE) and aroma extract dilution analysis (AEDA). Thirteen odorants were quantitated employing stable isotope dilution assays (SIDAs), and odor activity values (OAVs) were calculated. Odorants with OAVs >1 included 3-methylnonane-2,4-dione (hay, OAV 5800), β-ionone (floral, violets, OAV 2900), (2E,4E)-nona-2,4-dienal (fatty, OAV 1200), β-damascenone (cooked apple, OAV 370), hexanal (green, OAV 260), oct-1-en-3-one (mushroom, OAV 200), linalool (floral, citrus, OAV 61), (2E,4E)-deca-2,4-dienal (fatty, OAV 60), 2-phenylethanol (floral, rose, OAV 16), 3-(methylsulfanyl)propanal (potato, OAV 3.7), HDMF (caramel, OAV 2.0), and ethyl octanoate (fruity, OAV 1.1). An odor simulation model prepared using odorants with OAVs >1 sensorially matched the aroma of the Chardonnay marc skins. This investigation establishes a foundation for future studies aimed at determining the contribution of individual Chardonnay marc components (skins, seeds, and stems) to the aroma profile of Chardonnay marc powder and aiding producers in delivering optimal and consistent aroma profiles by region.

Comparison of key aroma-active compounds between roasted and cold-pressed sesame oils

SummaryThis study presents the application of a headspace solid‐phase microextraction (HS‐SPME) method on the analysis of Nebbiolo‐based wine volatiles by comprehensive two‐dimensional gas chromatography (GC×GC) and time‐of‐flight mass spectrometry (TOF‐MS). The aroma patterns were established for different samples of Nebbiolo‐based wines, aged in oak wood barrels for 18 months at constant temperature. The methodology allowed for the simultaneous analysis of over 130 different volatile compounds detected in the headspace. The odour activity values (OAVs) were assessed to identify potentially important odorants of Nebbiolo‐based wine during ageing. The highest OAVs were obtained for several compounds such as ethyl octanoate, ethyl hexanoate, isoamyl acetate, β‐damascenone, ethyl cinnamate, ethyl 3‐methylbutanate and acetaldehyde. Ethyl butanoate, octanoic acid, ethyl dihydrocinnamate and γ‐nonalactone were also at concentrations higher than their corresponding threshold. Also vanillin, (E)‐whisky lactone, (Z)‐whisky lactone, guaiacol and 4‐ethyl guaiacol seem to be important odorants after oak wood ageing period.

A headspace solid-phase microextraction (SPME) method was developed for the determination of secondary compounds from Brazilian sugar cane spirits, or cachaça, by GC-FID. An SPME holder with an 85 microm polyacrylate coating was utilized. The novel method is compared with an optimized method: liquid-liquid extraction (LLE). Both methods showed good linearity, but the repeatability for analyses done with the SPME technique (%RSD = 1.8-3.9) was better than for those done with LLE (%RSD = 10.3-11.7). The concentrations of the analytes obtained in the analysis of 12 cachaça samples with the SPME technique were higher than those obtained with LLE. In the SPME method the extraction wastes are smaller. Cachaça samples were qualitatively analyzed for GC-MS.

Comparative study of aroma profile and phenolic content of Montepulciano monovarietal red wines from the Marches and Abruzzo regions of Italy using HS-SPME–GC–MS and HPLC–MS

The application of headspace solid phase microextraction (SPME) for flavor analysis has been studied. Headspace SPME sampling was tested for nine common wine flavor compounds in 10% (v/v) aqueous ethanol: linalool, nerol, geraniol, 3-methyl-1-butanol, hexanol, 2-phenylethanol, ethyl hexanoate, ethyl octanoate, and ethyl decanoate. The chemical groups (monoterpenoids, aliphatic and aromatic alcohols, and esters) showed specific behavior in SPME analysis. SPME sampling parameters were optimized for these components. Relative response factors (RRFs), which establish the relationship between the concentration of the compound in the matrix liquid solution and the GC peak area, were estimated for all compounds. Log(10)(RRF) varied from 0 (3-methyl-1-butanol) to 3 (ethyl decanoate), according to their molecular weight. Quantification by SPME was shown to be highly dependent on the matrix composition; the compounds with higher RRF were the less affected. As a consequence, the data obtained with this methodology should be used taking into consideration these limitations, as shown in the analysis of four monovarietal Bairrada white wines (Arinto, Bical, Cerceal, and Maria Gomes).

The volatiles of cape gooseberry fruit (Physalis peruviana L.) were isolated by solvent-assisted flavor evaporation (SAFE), odor active compounds identified by gas chromatography–olfactometry (GC-O) and gas chromatography–mass spectrometry (GC-MS). Quantitation of compounds was performed by headspace—solid phase microextraction (HS-SPME) for all but one. Aroma extract dilution analysis (AEDA) revealed 18 odor active regions, with the highest flavor dilution values (FD = 512) noted for ethyl butanoate and 4-hydroxy-2,5-dimethylfuran-3-one (furaneol). Odor activity values were determined for all 18 compounds and the highest was noted for ethyl butanoate (OAV = 504), followed by linalool, (E)-non-2-enal, (2E,6Z)-nona-2,6-dienal, hexanal, ethyl octanoate, ethyl hexanoate, butane-2,3-dione, and 2-methylpropanal. The main groups of odor active compounds in Physalis peruviana L. were esters and aldehydes. A recombinant experiment confirmed the identification and quantitative results.

SummaryThe HS‐SPME‐GC‐MS analysis of Fiano di Avellino (white wine, Southern Italy) and Aglianico del Vulture (red wine, Southern Italy) showed the presence of ethyl acetate, 2‐methyl‐1‐propanol, 2‐methyl‐1‐butanol (MB), 2‐methylbutyl acetate (MBA), ethyl hexanoate (EH), diethyl butanedioate (DB), ethyl octanoate (EO) and ethyl decanoate (ED). UV irradiation of both the wines in a Pyrex vial with a 15‐W low pressure mercury arc showed an extensive degradation of all the compounds. After 24 h irradiation in the red wine, ethyl acetate decreased from 208 mg L−1 to 58 mg L−1, DB from 16.7 to 4 mg L−1, MBA from 19 to 3 mg L−1, 2‐methyl‐1‐propanol disappeared and MB decreased from 796 to 92.5 mg L−1. Only in the case of DB, MBA, EH, EO and ED in the red wine the degradation occurred after an initial increase of the concentrations of the esters. The irradiation of the esters in the presence of riboflavin showed a clear degradation of the esters (9%–17%). The irradiation of both the wines in the original bottles for 7 days showed an extensive degradation of all the volatile compounds observed in the wines. 2‐Methyl‐1‐propanol disappeared while 90% of MB disappeared. The amount of the esters decreases in the range 65%–91%.

The aromatic composition and key odorants of young red wines produced from Cabernet Sauvignon, Cabernet Franc, and Cabernet Gernischet wines were compared and the reasons for the difference in their aromatic compounds were discussed. Forty-three odorants were detected in Cabernet Sauvignon and Cabernet Franc wines compared to 50 in Cabernet Gernischet wine. Quantitatively, acids formed the most abundant group in the aromatic components of the 3 wines, followed by alcohols and esters. Compared to Cabernet Sauvignon and Cabernet Franc wines, the profiles of alcohols and esters for Cabernet Gernischet wine were more diverse. Monoterpenes, namely, 4-terpinenol, citronellol, and nerol, were found solely in Cabernet Gernischet wine. Only 10 compounds, namely, ethyl octanoate, ethyl hexanoate, isoamyl acetate, ethyl butyrate, beta-damascenone, ethyl decanoate, isoamyl alcohol, acetic acid, octanoic acid, and phenylethyl acetate, were always present in the 3 wines at concentrations higher than their threshold values. However, ethyl octanoate, ethyl hexanoate, and isoamyl acetate were found to jointly contribute to 97%, 98.9%, and 99% of the global aroma of Cabernet Sauvignon, Cabernet Franc, and Cabernet Gernischet wines, respectively. This result showed that the aroma indistinguishableness of the 3 wines was mainly due to the dominance of the fruity notes exerted by the ethyl esters and, to a lesser extent, to the contribution of varietal aromatic compounds to the global aroma of the wines.

Aroma profile of oxidatively aged White and Tawny Port wines with different indication of age. Contribution of the non-rectified wine spirit.

A method was developed for the analysis of volatile polar compounds in a water matrix using open cap vials Solid Phase Micro-Extraction (SPME) and Capillary Gas Chromatography (CGC). Both SPME techniques – direct sampling and headspace – were tested. Optimization of experimental conditions – exposure time, desorption time, with headspace SPME in addition the influence of the temperature and ionic strength of the sample solution on compound sorption, and finally GC response – were investigated. The analytes were extracted by directly immersing the 85 μm polyacrylate fiber in the aqueous sample or in the headspace. The linear range of the preconcentration process and the precision were examined. The amount of polar analytes sorbed on the fiber was determined and was found to be concentration dependent; it amounted to 0.014–0.64% in the concentration range of 0.00425–425 ppm studied in aqueous solution for direct sampling SPME and to 0.011–2.76% for solutions of concentration 0.0425–255 ppm for headspace SPME. The limits of determination were ascertained. Headspace SPME was applied to the analysis of real-life samples.

In this study, four types of Takju (rice wine) were developed using different fermentation starters; two traditional nuruk (SS and SJ), one ipguk (JE), and one crude amylolytic enzyme (HK), respectively. Sample rice wines were analyzed for ethanol, titratable acidity, pH, soluable solids, and Hunter colorimeter values. The Takju made with HK showed the highest ethanol level, while the titratable acidity of Takju made with JE was twice that of the other samples. The volatile compounds in the four types of Takju were isolated by headspace-solid phase microextraction (HSSPME) and analyzed by gas chromatography-mass spectrometry (GC-MS). A total of 49 volatile components were identified, including 27 esters, 3 acids, 10 alcohols, and 9 miscellaneous compounds. Ethyl esters and alcohols such as ethyl hexanoate, ethyl octanoate, ethyl decanoate, 2-methyl-1-pentanol, 1-pentanol, isoamyl alcohol, and 2-phenyl ethanol were the largest groups among the quantified volatiles. Although the numbers of detected volatile compounds were similar in the four types of Takju, the amount of quantified volatiles showed a great difference among samples.