Characterization of key odor-active compounds in sweet Petit Manseng (Vitis vinifera L.) wine by gas chromatography-olfactometry, aroma reconstitution, and omission tests.

Petit Manseng (Vitis vinifera L.) has become a popular variety in China for the production of semisweet and sweet wines. However, few studies focused on investigating the molecular odor code of its key odorants. In this study, the key odor-active compounds of Chinese sweet Petit Manseng wine were identified by gas chromatography-olfactometry (GC-O) and gas chromatography-mass spectrometry (GC-MS). Fifty-five odorous zones were sniffed and identified by application of aroma extraction dilution analysis on a distillate prepared by liquid-liquid extraction and solvent-assisted flavor evaporation. Among them, isoamyl alcohol, ethyl octanoate, isovaleric acid, (E)-ß-damascenone, and phenylethanol particularly displayed with highest flavor dilution factors above 1024. The quantification of volatiles by headspace solid-phase microextraction coupled with GC-MS and GC coupled with triple quadrupole MS/MS and a calculation of odor activity values (OAVs) indicated 23 volatiles with OAVs above 1. Ethyl hexanoate showed the highest OAV with 208.8, followed by (E)-ß-damascenone (189.0), 3-mercaptohexanol (60.3), isoamyl acetate (45.4), and furaneol (40.1). The aroma of the sweet wine was successfully reconstituted by combining 42 aroma compounds in a model wine solution. 3-Mercaptohexanol, (E)-ß-damascenone, furaneol, γ-octalactone + γ-decalactone + γ-hexalactone, and ethyl cinnamate had important influence on the aroma of sweet Petit Manseng wine assessed by omission tests. Moreover, the discrimination of wines from three regions was successfully achieved by partial least squares discriminant analysis based on quantitative results of key odorants. 3-Mercaptohexanol was considered as the most responsible for the region discrimination and had highest concentrations in Petit Manseng wines from Jiaodong Peninsula. PRACTICAL APPLICATION: Understanding of the knowledge in key odorants of Petit Manseng wines could be useful to improve wine quality through viticultural and enological practices.

Characterization of the effect of cis-3-hexen-1-ol on green tea aroma.

cis-3-Hexen-1-ol has been regarded as the main source of green aroma (or green odor) in green tea. However, no clear findings on the composition of green aroma components in tea and the effect of cis-3-hexen-1-ol on other aroma components have been reported. In this study, the main green aroma components in green tea were characterized, especially the role of cis-3-hexen-1-ol in green aroma was analyzed and how it affected other aroma components in green tea was studied. Based on the GC-MS detection, odor activity value evaluation, and monomer sniffing, 12 green components were identified. Through the chemometric analysis, cis-3-hexen-1-ol was proven as the most influential component of green aroma. Moreover, through the electronic nose analysis of different concentrations of cis-3-hexen-1-ol with 25 other aroma components in green tea, we showed that the effect of cis-3-hexen-1-ol plays a profound effect on the overall aroma based on the experiments of reconstitution solution and natural tea samples. GC-MS and CG-FID confirmed that the concentration range of the differential threshold of green odor and green aroma of cis-3-hexen-1-ol was 0.04-0.52 mg kg-1.

Investigations into the production of volatile compounds in Korla fragrant pears (Pyrus sinkiangensis Yu).

The composition of volatile compounds in Korla fragrant pears was determined using headspace solid-phase microextraction followed by a gas chromatography-mass spectrometry analysis using fruits at 30, 90, and 150 days after bloom. Hexanal, (E)-2-hexenal, 1-hexanol, (E)-2-hexen-1-ol, (Z)-3-hexen-1-ol, and hexyl acetate were identified as the major compounds. The composition of volatile compounds was associated with fatty acid concentrations and key enzyme activity in the lipoxygenase pathway. In vitro linoleic and linolenic acid feeding experiments conducted using cubes of fruit flesh demonstrated that the concentrations of volatile esters, such as hexyl acetate, in the treated fruits increased significantly after incubation for 12 h compared with those in the control fruits, which was accompanied by a reduction in aldehyde and alcohol concentrations (p < 0.05 or p < 0.01). However, the treatments did not significantly influence the enzyme activity and expression of genes encoding the enzymes.

Emissions of DEHP-free PVC flooring.

Degrading 2-ethylhexyl-containing PVC floorings (eg DEHP-PVC floorings) and adhesives emit 2-ethylhexanol (2-EH) in the indoor air. The danger of flooring degradation comes from exposing occupants to harmful phthalates plasticisers (eg DEHP), but not from 2-EH as such. Since the EU banned the use of phthalates in sensitive applications, the market is shifting to use DEHP-free and alternative types of plasticisers in PVC products. However, data on emissions from DEHP-free PVC floorings are scarce. This study aimed at assessing the surface and bulk emissions of two DEHP-free PVC floorings over three years. The floorings were glued on the screed layer of concrete casts at 75%, 85%, and 95% RH. The volatile organic compounds (VOCs) were actively sampled using FLEC (surface emissions) and micro-chamber/thermal extractor (µ-CTE, bulk emissions) onto Tenax TA adsorbents and analyzed with TD-GC-MS. 2-EH, C9-alcohols, and total volatile organic compound (TVOC) emissions are reported. Emissions at 75% and 85% RH were similar. As expected, the highest emissions occurred at 95% RH. 2-EH emissions originated from the adhesive. Because the two DEHP-free floorings tested emitted C9-alcohols at all tested RH, it makes the detection of flooring degradation harder, particularly if the adhesive used does not emit 2-EH.

Effect of polyvinylpolypyrrolidone treatment on rosés wines during fermentation: Impact on color, polyphenols and thiol aromas.

Fining treatment with polyvinylpolypyrrolidone (PVPP) is often used during winemaking of rosé wines. It can modulate the intensity and hue of their pink color and prevent some organoleptic degradations. In this paper, the effect of PVPP treatments on rosé wine during fermentation was investigated by measuring color, polyphenol content and thiol aromas. As expected, colorimetry results showed a decrease in color, indicating some adsorption of anthocyanins and other pigments. This was confirmed by UPLC-ESI-MS/MS analyses. Specific adsorption of certain families of polyphenols was evidenced. Flavonols, flavanols and anthocyanins, especially coumaroylated anthocyanins were preferentially adsorbed by PVPP. The thiol content (3-sulfanylhexyl acetate (3SHA) and 3-sulfanylhexan-1-ol (3SH)) was usually higher after PVPP treatments, in a dose dependent manner. A possible explanation is that the partial adsorption of some polyphenols at an early stage of fermentation would later limit the amount of quinone compounds able to trap thiol aromas.

Volatile profiles of fresh rice noodles fermented with pure and mixed cultures.

The volatile profiles of fresh rice noodles (FRN) fermented with pure and five commercial mixed cultures were studied by using solid phase micro extraction/ gas chromatography-mass spectrometry, electronic nose, and sensory evaluations. The main volatile compounds of FRN by pure culture included aldehydes represented by nonanal, octanal, and 2,4-Pentadienal, and alcohols represented by hexanol and 1-nonanol. Its aroma profiles showed remarkable changes during the storage time from 0 to 30 h, indicating the reduction in aldehydes and the increase in alcohols and isoamyl alcohol. Significant variations such as the types, relative amounts, and category distributions of volatile compounds were observed in FRN by five mixed cultures. The bacterial compositions of these mixed cultures were quite different, which might be responsible for the significant variations in volatile profiles. Principal component analysis on E-nose data demonstrated that FRN by Culture A, B, and C shared similar flavor, while FRN by Culture D and E possessed different aroma compared to the above three. FRN produced with pure fermentation showed the highest score in sensory evaluation, whereas FRN by mixed cultures indicated rice fragrance, light fragrance, peculiar smell, or foul smell.

Identification and quantification of glue-like off-odors in elastic therapeutic tapes.

Elastic therapeutic tapes are an important tool in the field of physical therapy and medicine. These tapes contain types of adhesive. However, sensory evaluations revealed the release of pronounced and irritating odors of the tapes. Negative odors were, amongst others, reported in elastic therapeutic tapes containing acrylic adhesives. In this study, the odor of four different tape samples was evaluated applying a descriptive analysis approach carried out by a trained sensory panel. Afterwards, the volatile compounds were recovered from the samples by solvent extraction and isolated by solvent-assisted flavor evaporation (SAFE). The obtained distillates were subsequently analyzed by gas chromatography-olfactometry (GC-O) and two-dimensional GC-O coupled with mass spectrometry (2D-GC-MS/O). To determine the most potent odorants in the distillates, odor extract dilution analyses (OEDA) were carried out. Thirty-one odorants were successfully identified using this approach, which were all described for the first time as odorants in tapes. Amongst the set of volatiles, unsaturated and saturated aldehydes were present, eliciting fatty, soapy, and citrus-like odor impressions, as well as a range of glue-like, moldy, and fruity smelling odor-active volatiles, such as 2-ethyl-1-hexanol, butyl benzoate, and 3-phenyltoluene. Based on their relative intensities, the concentrations of the glue-like smelling substances were determined: 2-ethyl-1-hexanol, present in all samples, was determined with concentrations ranging from 10 to 200 mg/kg in the investigated tapes.

Exploring a volatomic-based strategy for a fingerprinting approach of Vaccinium padifolium L. berries at different ripening stages.

The effect of ripening on the evolution of the volatomic pattern from endemic Vaccinium padifolium L. (Uveira) berries was investigated using headspace-solid phase microextraction (HS-SPME) followed by gas chromatography/quadrupole-mass spectrometry (GC-qMS) and multivariate statistical analysis (MVA). The most significant HS-SPME parameters, namely fibre polymer, ionic strength and extraction time, were optimized in order to improve extraction efficiency. Under optimal experimental conditions (DVB/CAR/PDMS fibre coating, 40°C, 30min extraction time and 5g of sample amount), a total of 72 volatiles of different functionalities were isolated and identified. Terpenes followed by higher alcohols and esters were the predominant classes in the ripening stages - green, break and ripe. Although significant differences in the volatomic profiles at the three stages were obtained, cis-ß-ocimene (2.0-40.0%), trans-2-hexenol (2.4-19.4%), cis-3-hexenol (2.5.16.4%), ß-myrcene (1.9-13.8%), 1-hexanol (1.7-13.6%), 2-hexenal (0.7-8.0%), 2-heptanone (0.7-7.7%), and linalool (1.9-6.1%) were the main volatile compounds identified. Higher alcohols, carboxylic acids and ketones gradually increased during ripening, whereas monoterpenes significantly decreased. These trends were dominated by the higher alcohols (1-hexanol, cis-3-hexenol, trans-2-hexenol) and monoterpenes (ß-myrcene, cis-ß-ocimene and trans-ß-ocimene). Partial least squares regression (PLSR) revealed that ethyl caprylate (1.000), trans-geraniol (0.995), ethyl isovalerate (-0.994) and benzyl carbinol (0.993) are the key variables that most contributed to the successful differentiation of Uveira berries according to ripening stage. To the best of our knowledge, no study has carried out on the volatomic composition of berries from endemic Uveira.

Effect of regulated deficit irrigation on fatty acids and their derived volatiles in 'Cabernet Sauvignon' grapes and wines of Ningxia, China.

The effect of regulated deficit irrigation (RDI) on fatty acids and their derived volatiles in 'Cabernet Sauvignon' grapes and wines was investigated during two growing seasons in the east foot of Mt. Helan, the semi-arid area. The vines received water with 60% (RDI-1), 70% (RDI-2), 80% (RDI-3), 100% (CK, traditional drip irrigation) of their estimated evapotranspiration (ETc) respectively. RDI treatments resulted in lower yield, berry weight and titratable acidity with higher total soluble solids. RDI-1 increased the content of unsaturated fatty acids in berries and decreased the level of alcohols and esters volatiles in wines. RDI-2 and RDI-3 enhanced 1-hexanol and esters in wines in comparison with CK. The concentrations of C6 aroma compounds were closely correlated with unsaturated fatty acids (p < .05), especially linolenic acid and linoleic acid. The present results provided direct evidence and detailed data to explain the effect of RDI on grapes and wines composition regarding fatty acids and their derived volatiles.

Assessment of filtration efficiency and physiological responses of selected plant species to indoor air pollutants (toluene and 2-ethylhexanol) under chamber conditions.

Three common plant species (Dieffenbachia maculata, Spathiphyllum wallisii, and Asparagus densiflorus) were tested against their capacity to remove the air pollutants toluene (20.0 mg m-3) and 2-ethylhexanol (14.6 mg m-3) under light or under dark in chamber experiments of 48-h duration. Results revealed only limited pollutant filtration capabilities and indicate that aerial plant parts of the tested species are only of limited value for indoor air quality improvement. The removal rate constant ranged for toluene from 3.4 to 5.7 L h-1 m-2 leaf area with no significant differences between plant species or light conditions (light/dark). The values for 2-ethylhexanol were somewhat lower, fluctuating around 2 L h-1 m-2 leaf area for all plant species tested, whereas differences between light and dark were observed for two of the three species. In addition to pollutant removal, CO2 fixation/respiration and transpiration as well as quantum yield were evaluated. These physiological characteristics seem to have no major impact on the VOC removal rate constant. Exposure to toluene or 2-ethylhexanol revealed no or only minor effects on D. maculata and S. wallisii. In contrast, a decrease in quantum yield and CO2 fixation was observed for A. densiflorus when exposed to 2-ethylhexanol or toluene under light, indicating phytotoxic effects in this species.

Ageing and retail display time in raw beef odour according to the degree of lipid oxidation.

This study aims to assess the changes in beef aroma over time when steaks from pre-aged knuckles are stored in retail display under high oxygen conditions for 15 or 22days in vacuum conditions. Odorous volatile compounds were analysed by solid-phase microextraction/gas chromatography-mass spectrometry. Results were grouped as low, medium and high oxidative groups according to thiobarbituric acid reactive substances values after 9days of display. The intensity of off-odours in the raw meat increased with ageing and display time and oxidative groups. Based on correlations between the variables and regressions of the compounds through display, eight compounds were proposed as odour shelf-life markers. Among them, five were most sensitive and precise in all oxidative groups: 1-hexanol in meat aged for 15days, ethyl- octanoate and 2-pentylfuran in meat aged for 22days, and pentanoic and hexanoic acids in the two studied ageing times.

Chiral analysis of 3-sulfanylhexan-1-ol and 3-sulfanylhexyl acetate in wine by high-performance liquid chromatography-tandem mass spectrometry.

A number of polyfunctional thiols are well-recognised as some of the most potent aroma compounds in nature and have been identified in various foods, and beverages such as wine. These potent character impact compounds are present at nanogram-per-litre levels and are particularly challenging to measure. Where present, enantiomeric forms having different odour qualities further complicate the analysis. In this work, a chiral high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) method using stable isotope dilution analysis (SIDA) has been developed and validated for the individual enantiomers of 3-sulfanylhexan-1-ol (3-SH, 1) and its O-acetate, 3-sulfanylhexyl acetate (3-SHA, 2), in wine after extraction as their 4-thiopyridine derivatives. Authentic derivatised thiols were first synthesised and used for chiral column screening and method development with polysaccharide-based HPLC phases. Validation of the method using a Lux Amylose-1 column for quantification of the enantiomers of 1 and 2 gave linear calibrations, and excellent figures for accuracy (recovery: 90%-111%, Z-score: -1.8-1.9), precision (RSDr<8%), and limits of detection (0.7 ng L-1 or less) in model media and different wine matrices. The newly developed method was applied to determine the enantiomer profiles of 1 and 2 in range of commercial wines.

The individual contribution of starter and non-starter lactic acid bacteria to the volatile organic compound composition of Caciocavallo Palermitano cheese.

The contribution of two starter (Lactobacillus delbrueckii and Streptococcus thermophilus) and nine non-starter (Enterococcus casselliflavus, Enterococcus faecalis, Enterococcus durans, Enterococcus gallinarum, Lactobacillus casei, Lactobacillus paracasei, Lactobacillus rhamnosus, Pediococcus acidilactici and Pediococcus pentosaceus) species of lactic acid bacteria (LAB) to the volatile organic compounds (VOCs) of Caciocavallo Palermitano cheese was investigated. The strains used in this study were isolated during the production/ripening of the stretched cheese and tested in a cheese-based medium (CBM). The fermented substrates were analyzed for the growth of the single strains and subjected to the head space solid phase micro-extraction (HS-SPME) and gas chromatography - mass spectrometry (GC-MS). The 11 strains tested were all able to increase their numbers in CBM, even though the development of the starter LAB was quite limited. GC-MS analysis registered 43 compounds including seven chemical classes. A lower diversity of VOCs was registered for the unfermented curd based medium (CuBM) analyzed for comparison. The class of ketones represented a consistent percentage of the VOCs for almost all LAB, followed by alcohols and esters. The volatile profile of Pediococcus acidilactici and Lactobacillus delbrueckii was mainly characterized by 2-butanol, butanoic acid and hexanoic acid and their esters, while that of Lactobacillus casei and Lactobacillus rhamnosus was characterized by 2,3-butanedione and 2-butanone, 3-hydroxy. In order to correlate the VOCs produced by Caciocavallo Palermitano cheeses with those generated by individual LAB, the 4-month ripened cheeses resulting from the dairy process monitored during the isolation of LAB were also analyzed for the volatile chemical fraction and the compounds in common were subjected to a multivariate statistical analysis. The canonical analysis indicated that the VOCs of the ripened cheeses were mainly influenced by E. gallinarum, L. paracasei, L. delbrueckii, L. rhamnosus and L. casei and that 1-hexanol, o-xylene and m-xylene were the cheese VOCs highly correlated with LAB.

Characteristic Flavor of Traditional Soup Made by Stewing Chinese Yellow-Feather Chickens.

The traditional recipe for Chinese chicken soup creates a popular taste of particular umami and aroma. The present study investigated the effects of stewing time (1, 2, and 3 h) on the principal taste-active and volatile compounds and the overall flavor profile of traditional Chinese chicken soup by measuring the contents of free amino acids (FAAs), 5'-nucleotides, minerals and volatile compounds and by evaluating the taste and aroma profiles using an electronic nose, an electronic tongue and a human panel. Results showed that the major umami-related compounds in the chicken soup were inosine 5'-monophosphate (IMP) and chloride, both of which increased significantly (P < 0.05) during stewing. The taste active values (TAVs) of the equivalent umami concentration (EUC) increased from 4.08 to 9.93 (P < 0.05) after stewing for 3 h. Although the FAA and mineral contents increased significantly (P < 0.05), their TAVs were less than 1. The volatile compounds were mainly hexanal, heptanal, octanal, nonanal, (E)-2-nonanal, (E)-2-decenal, (E,E)-2,4-decadienal, 1-hexanol, and 2-pentyl furan. With the prolonged stewing time, the aldehydes first increased and then decreased significantly (P < 0.05), while 1-hexanol and 2-pentyl furan increased steadily (P < 0.05). The aroma scores of the chicken soup reached the maximum after stewing for 3 h. The discrepancy in overall flavor characteristics tended to stabilize after 2 h of stewing. In general, stewing time has a positive effect on improving the flavor profiles of chicken soup, especially within the first 2 h.

Indications of the prominent role of elemental sulfur in the formation of the varietal thiol 3-mercaptohexanol in Sauvignon blanc wine.

Elemental sulfur is a fungicide traditionally used to control Powdery Mildew in the production of grapes. The presence of sulfur residues in grape juice has been associated with increased production of hydrogen sulfide during fermentation, which could take part in the formation of the varietal thiol 3-mercaptohexanol. This work examines whether elemental sulfur additions to Sauvignon blanc juice can increase the levels of sought-after varietal thiols. Initial trials were performed in South Africa and indicated a positive impact of sulfur on the levels of thiols. Further experiments were then carried out with New Zealand Sauvignon blanc and confirmed a positive relationship between elemental sulfur additions and wine varietal thiols. The formation of hydrogen sulfide was observed when the addition of elemental sulfur was made to clarified juice, along with an increase in further reductive sulfur compounds. When the addition of sulfur was made to pressed juice, prior to clarification, the production of reductive sulfur compounds was drastically decreased. Some mechanistic considerations are also presented, involving the reduction of sulfur to hydrogen sulfide prior to fermentation.

An endophytic Fusarium sp. isolated from Monarda citriodora produces the industrially important plant-like volatile organic compound hexanal.

An endophytic fungus, MC_25L, has been isolated from the leaves of MonardacitriodoraCerv. ex Lag., a medicinal and aromatic herb from the northwestern Himalayas. It produces a fruity fragrance while growing on potato dextrose agar, suggesting that it is producing volatile organic compounds (VOCs). The endophyte inhibited the growth of plant pathogens such asSclerotiniasp. and Aspergillusflavus by virtue of VOCs. Identification of MC_25L based on morphological and microscopic features, as well as ITS-based rDNA sequence analysis, revealed that it is a Fusariumsp. GC-MS analysis revealed that this endophyte produces a unique array of VOCs, in particular hexanal, p-fluoroanisole, pentafluoropropionic acid 2-ethylhexyl, (5E)-5-ethyl-2-methyl-5-hepten-3-one, 2-butyl-2-hexanol, (7E)-2-methyl-7-hexadecene and acoradiene. Three major compounds were hexanal, (5E)-5-ethyl-2-methyl-5-hepten-3-one and acoradiene, and they account for around 84.57 % of the total VOCs. Moreover, of interest was the presence of hexanal, which has applications in the food and cosmetic industries, as well as in mycofumigation. This is the first report of a fungal endophyte producing the industrially important plant-like VOC hexanal. Hexanal is also active biologically. Thus this study indicates that Fusariumsp. (MC_25L) is a potential candidate for the up-scaling of hexanal.

Cooking impact in color, pigments and volatile composition of grapevine leaves (Vitis vinifera L. var. Malvasia Fina and Touriga Franca).

Grapevine leaves (Vitis vinifera L. var. Malvasia Fina and Touriga Franca) under culinary treatment (blanching and boiling at 60, 75 and 90min) were studied for their color, pigments and volatile fraction changes. Blanching and boiling caused a decrease in luminosity and a loss of green coloration in both varieties, while a yellow-brownish color arose. Significant correlations were established between the loss of green color (monochromatic variable a∗) and the total chlorophylls content. The main volatiles in fresh leaves [(Z)-3-hexenal, (Z)-3-hexen-1-ol, and (Z)-3-hexenyl acetate] were drastically reduced by blanching and suppressed by boiling. Other compounds like pentanal and 6-methyl-5-hepten-2 one arose from blanching and boiling. A boiling time of 60min is adequate for the culinary process of grapevine leaves, since the product is considered edible and the pigments and volatile changes are not as drastic as observed at 75 and 90min of boiling.

Metabolome based volatiles profiling in 13 date palm fruit varieties from Egypt via SPME GC-MS and chemometrics.

Dates (Phoenix dactylifera L.) are distributed worldwide as major food complement providing a source of sugars and dietary fiber as well as macro- and micronutrients. Although phytochemical analyses of date fruit non-volatile metabolites have been reported, much less is known about the aroma given off by the fruit, which is critical for dissecting sensory properties and quality traits. Volatile constituents from 13 date varieties grown in Egypt were profiled using SPME-GCMS coupled to multivariate data analysis to explore date fruit aroma composition and investigate potential future uses by food industry. A total of 89 volatiles were identified where lipid-derived volatiles and phenylpropanoid derivatives were the major components of date fruit aroma. Multivariate data analyses revealed that 2,3-butanediol, hexanal, hexanol and cinnamaldehyde contributed the most to classification of different varieties. This study provides the most complete map of volatiles in Egyptian date fruit, with Siwi and Sheshi varieties exhibiting the most distinct aroma among studied date varieties.

Aroma-Active Compounds in Bartlett Pears and Their Changes during the Manufacturing Process of Bartlett Pear Brandy.

Application of aroma extract dilution analysis to Bartlett pears and the fermented mash produced thereof revealed 24 and 34 aroma-active compounds in the flavor dilution (FD) factor range between 8 and 8192. Twenty-eight compounds, which have not been described before in Bartlett pears or in fermented pear mash, were identified. While ethyl (E,Z)-2,4-decadienoate (pear-like, metallic odor impression), hexyl acetate (green, fruity), and acetic acid (vinegar-like) showed the highest concentrations in Bartlett pears, ethanol (ethanolic), acetic acid, 3-methyl-1-butanol (malty), 1-hexanol (grassy, marzipan-like), (S)-2- and 3-methylbutanoic acid (sweaty), and 2-phenylethanol (flowery, honey-like) were present at the highest amounts in the fermented mash. The key aroma compounds were quantitated in each pear brandy production step (pears, fermented mash, distillate, and aged distillate) by stable isotope dilution analysis showing a clear influence of each step on the overall aroma of the spirit and, consequently, revealing clearly changing concentrations (e.g., of ethyl (S)-2-methylbutanoate, (E)-ß-damascenone, ethyl (E,Z)-2,4-decadienoate, and ethyl (E,E)-2,4-decadienoate) and different aroma perceptions during the manufacturing process. In addition, the concentrations of the so-called "pear esters" ethyl (E,Z)-2,4-decadienoate and ethyl (E,E)-2,4-decadienoate were determined in 6 different pear varieties (Abate Fetel, Anjou, Bartlett, Forelle, Kaiser Alexander, and Packham's Triumph) clearly demonstrating the aroma potential of the variety Bartlett, which is mostly used for brandy production due to the high amounts of both esters eliciting a typical pear-like odor impression.