Ethyl 2-methylbutyrate Research Articles

Volatile aroma compound-based decoding and prediction of sweet berry aromas in dry red wine

To explore the volatile markers of typical sweet berry flavors in dry red wine, Marselan, Cabernet Sauvignon, Merlot, and Cabernet Franc wines were pretreated using solid-phase microextraction (SPME) and liquid-liquid extraction-solvent-assisted flavor evaporation (LLE-SAFE), and key odorants were analyzed using sensomics approach. Results indicated that Marselan wines exhibited intense sweet berry aromas compared to other varieties wines. Omission tests on one- and four-year-aged wines identified β-damascenone, isoamyl acetate, 2,3-butanediol, phenylethanol as sweet aroma markers, while geranyl acetone, ethyl isobutyrate, ethyl 2-methylbutyrate as berry aroma markers, which were verified by partial least squares regression. Meanwhile, optimal flavor intensity prediction models between sweet/berry aroma and volatile markers natural logarithms concentration were created with all wines. Moreover, consistent with aroma intensity, most berry markers content increased during aging while sweet markers decreased. This study completes the analytical methodology for volatile markers of wine typical aroma and provides theoretical support for wine flavor prediction.

Analysis of Aroma Characteristics of 'Binzi' and 'Xiangguo' Apple-Ancient Cultivars in China.

'Binzi' (BZ) (Malus domestica subsp. chinensis var. binzi Li Y.N.) and 'Xiangguo' (XG) (Malus domestica subsp. chinensis var. xiangguo Li Y.N.) are the ancient cultivars in China. The BZ fruits have a low-fragrant flavor on harvest day but a high-fragrant flavor after storage at room temperature, while the XG fruits have a stronger flavor when mature. 'Starking' (SK) and 'Golden Delicious' (GD) fruits have a rich flavor and are recognized by all countries in the world. However, information on the differences between ancient Chinese cultivars and Western apple cultivars in aroma compounds remains unknown. The apple fruits were collected for continuous two years. Aroma compounds in the skin and pulp of the fruits were detected at room temperature (20 ± 1 °C) during storage. The dynamics of VOCs in BZ and SK fruits were more similarly reflected in esters, while those of XG and GD fruits were reflected in aldehydes and alcohols. Ethyl 2-methylbutyrate, with an extremely low odor threshold, was the main source of typical apple flavor in SK, BZ, and XG fruits, while hexyl acetate was the source of the banana flavor in GD fruits. 6-methyl-5-hepten-2-one and β-damascenone were the important ketones produced in the later stage of storage, derived from the carotenoid metabolism pathway and providing a citrus and rose flavor to the four apple cultivars. SK had the highest number of characteristic aroma components, which were mainly derived from the amino acid metabolism pathway, providing fruits with a sweet and fruity flavor. Although the characteristic aroma components of GD were derived from the fatty acid metabolic pathway, the number of volatile esters was lower. Ethyl butyrate, derived from the saturated fatty acid metabolism, had the highest content in BZ, providing a pineapple flavor; the flavor of XG was mainly derived from ethyl 2-methylbutyrate, 6-methyl-5-hepten-2-one, and β-damascenone. Therefore, we suggest BZ and XG apples as the aroma-breeding material with which to enrich new cultivars' aroma components, derived from the fatty acid metabolism and carotenoid metabolism pathways, respectively.

Chemical Characterization of Cider Produced in Hardanger—From Juice to Finished Cider

Our investigation delves into the previously uncharted territory of cider composition from Norway. This study aimed to obtain an overview of the qualitative and quantitative compositions of general chemical parameters, polyphenols (individual and total expressed as gallic acids equivalents), selected esters, and selected C6-alcohols in ciders with the PDO label Cider from Hardanger. In total, 45 juice and cider samples from the fermentation process were collected from 10 cider producers in Hardanger in 2019, 2020, and 2021. Individual sugars, acids, ethanol, and 13 individual phenols were quantified using HPLC-UV/RI. Seven ethyl esters of fatty acids, four ethyl esters of branched fatty acids, ten acetate esters, two ethyl esters of hydroxycinnamic acids, and four C6-alcohols were quantified using HS-SPME-GC-MS. For samples of single cultivars (‘Aroma’, ‘Discovery’, ‘Gravenstein’, and ‘Summerred’), the sum of the measured individual polyphenols in the samples ranges, on average, from 79 to 289 mg L−1 (the lowest for ‘Summerred’ and highest for ‘Discovery’ and ‘Gravenstein’). Chlorogenic acid was the most abundant polyphenol in all samples. Ethyl butyrate, ethyl hexanoate, ethyl octanoate, ethyl decanoate, ethyl isobutyrate, ethyl 2-methylbutyrate, isoamyl acetate, and hexanol were present at concentrations above the odour threshold and contributed to the fruity flavour of the Cider from Hardanger.

Evolution of Aroma Profiles in Vitis vinifera L. Marselan and Merlot from Grapes to Wines and Difference between Varieties.

The fermentation process has a significant impact on the aromatic profile of wines, particularly in relation to the difference in fermentation matrix caused by grape varieties. This study investigates the leaching and evolution patterns of aroma compounds in Vitis vinifera L. Marselan and Merlot during an industrial-scale vinification process, including the stages of cold soak, alcohol fermentation, malolactic fermentation, and one-year bottle storage. The emphasis is on the differences between the two varieties. The results indicated that most alcohols were rapidly leached during the cold soak stage. Certain C6 alcohols, terpenes, and norisoprenoids showed faster leaching rates in 'Marselan', compared to 'Merlot'. Some branched chain fatty-acid esters, such as ethyl 3-methylbutyrate, ethyl 2-methylbutyrate, and ethyl lactate, consistently increased during the fermentation and bottling stages, with faster accumulation observed in 'Marselan'. The study combines the Orthogonal Partial Least Squares-Discriminant Analysis (OPLS-DA) model based on odor activity values to elucidate the accumulation of these ethyl esters during bottle storage, compensating for the reduction in fruity aroma resulting from decreased levels of (E)-β-damascenone. The 'Marselan' wine exhibited a more pronounced floral aroma due to its higher level of linalool, compared to the 'Merlot' wine. The study unveils the distinctive variation patterns of aroma compounds from grapes to wine across grape varieties. This provides a theoretical framework for the precise regulation of wine aroma and flavor, and holds significant production value.

Molecular Analysis of Volatile Metabolites Synthesized by Candida albicans and Staphylococcus aureus in In Vitro Cultures and Bronchoalveolar Lavage Specimens Reflecting Single- or Duo-Factor Pneumonia.

Current microbiological methods for pneumonia diagnosis require invasive specimen collection and time-consuming analytical procedures. There is a need for less invasive and faster methods to detect lower respiratory tract infections. The analysis of volatile metabolites excreted by pathogenic microorganisms provides the basis for developing such a method. Given the synergistic role of Candida albicans in increasing the virulence of pathogenic bacteria causing pneumonia and the cross-kingdom metabolic interactions between microorganisms, we compare the emission of volatiles from Candida albicans yeasts and the bacteria Staphylococcus aureus using single and mixed co-cultures and apply that knowledge to human in vivo investigations. Gas chromatography-mass spectrometry (GC-MS) analysis resulted in the identification of sixty-eight volatiles that were found to have significantly different levels in cultures compared to reference medium samples. Certain volatiles were found in co-cultures that mainly originated from C. albicans metabolism (e.g., isobutyl acetate), whereas other volatiles primarily came from S. aureus (e.g., ethyl 2-methylbutyrate). Isopentyl valerate reflects synergic interactions of both microbes, as its level in co-cultures was found to be approximately three times higher than the sum of its amounts in monocultures. Hydrophilic-lipophilic-balanced (HLB) coated meshes for thin-film microextraction (TFME) were used to preconcentrate volatiles directly from bronchoalveolar lavage (BAL) specimens collected from patients suffering from ventilation-associated pneumonia (VAP), which was caused explicitly by C. albicans and S. aureus. GC-MS analyses confirmed the existence of in vitro-elucidated microbial VOCs in human specimens. Significant differences in BAL-extracted amounts respective to the pathogen-causing pneumonia were found. The model in vitro experiments provided evidence that cross-kingdom interactions between pathogenic microorganisms affect the synthesis of volatile compounds. The TFME meshes coated with HLB particles proved to be suitable for extracting VOCs from human material, enabling the translation of in vitro experiments on the microbial volatilome to the in vivo situation involving infected patients. This indicates the direction that should be taken for further clinical studies on VAP diagnosis based on volatile analysis.

Comparative analysis of the aromatic profile of single malt whiskies from different regions of Scotland using GC-MS, GC-O-MS and sensory evaluation

Single malt whiskies are popular around the world. The 37 esters, 10 alcohols, 10 phenols, 8 aldehydes, 8 acids, 6 alkanes, 4 ketones and 3 heterocycles were detected in the single malt whiskies extracted from different origins in Scotland by HS-SPME (headspace solid-phase microextraction) and LLE (liquid-liquid extraction) and identified by GC-MS (gas chromatography-mass spectrometry). QDA (quantitative descriptive analysis) combined with multivariate statistics were used to investigate the effects of the differential aroma-active compounds on the sensory aroma characteristics. O-cresol, ethyl 2-methylbutyrate, 5-methylfurfural and propionic acid might influence the flavor of single malt whiskies of different origins in Scotland. The 54 key whisky aroma compounds were analyzed, with isoamyl acetate having the highest OAV (odour activity value) of all whisky samples. In addition, the aromas of volatile compounds were analyzed using OSME (odor-specific magnitude estimation) and OAV. Based on these facts, the researchers developed a flavour wheel with 10 aroma profiles. This paper evaluates Scotch single malt whisky from a Chinese perspective, which helps the development of the Chinese whisky market.

Impact of aroma-enhancing microorganisms on aroma attributes of industrial Douchi: An integrated analysis using E-nose, GC-IMS, GC–MS, and descriptive sensory evaluation

In order to enhance the aromatic profile of industrial Douchi, a comprehensive investigation was undertaken to assess the impact of aroma-enhancing microorganisms on the sensory attributes of Douchi. This evaluation utilized a combination of analytical techniques, including electronic nose analysis, gas chromatography-ion mobility spectrometry (GC-IMS), gas chromatography-mass spectrometry (GC–MS), and descriptive sensory analysis (DA). Both GC-IMS and GC–MS revealed significant changes in the volatile composition of Douchi following the addition of aroma-enhancing microorganisms (p < 0.05). Partial least squares-discriminant analysis (PLS-DA) identified benzaldehyde, benzene acetaldehyde, 3-octanone, and ethyl 2-methylbutyrate as significant differentiating volatile compounds. Additionally, compared to the control group, the sensory attributes of sourness in Douchi were significantly reduced (p < 0.001), while the attributes of wine-like and sweetness were notably enhanced (p < 0.05) when the ratio of G. candidum to C. versatilis was 1:1 (GCC group). By calculating the odor-activity values (OAVs) of key volatiles, it can be hypothesized that this aroma improvement of Douchi may be attributed to an increase in the typical volatiles (3-methyl-1-butanol, 1-octen-3-ol, 3-octanol, and 3-octanone) and ethyl 2-methylbutanoate with high OAVs (2340849.64 ∼ 16695327.86), as well as to decreases in the musty acetophenone. In conclusion, the aroma profile of Douchi was significantly enhanced when G. candidum and C. versatilis were added at a ratio of 1:1. This study provides valuable insights into the development of aroma enhancers for improving the sensory profile of Douchi.

Characterization and comparison of flavors in fresh and aged fermented peppers: Impact of different varieties

The flavor profiles of fresh and aged fermented peppers obtained from four varieties were thoroughly compared in this study. A total of 385 volatile compounds in fermented pepper samples were detected by flavoromics (two-dimensional gas chromatography–time-of-flight mass spectrometry). As fermentation progressed, both the number and the total concentration of volatile compounds changed, with esters, alcohols, acids, terpenoids, sulfur compounds, and funans increasing, whereas hydrocarbons and benzenes decreased. In contrast to the fresh fermented peppers, the aged fermented samples exhibited lower values of pH, total sugars, and capsaicinoids but higher contents of organic acids and free amino acids. Furthermore, the specific differences and characteristic aroma substances among aged fermented peppers were unveiled by multivariate statistical analysis. Overall, 64 volatiles were screened as differential compounds. In addition, Huanggongjiao samples possessed the most abundant differential volatiles and compounds with odor activity values > 1, which were flavored with fruity, floral, and slightly phenolic odors. Correlation analysis demonstrated that the levels of 23 key aroma compounds (e.g., ethyl 2-methylbutyrate, 1-butanol, and ethyl valerate) showed a significantly positive correlation with Asp, Glu and 5 organic acids. By contrast, there is a negative association between the pH value and total sugar. Overall, aging contributed significantly to the flavor attributes of fermented peppers.

Characterization of the Volatile Composition of Fermented Ciders Made From Dessert Apple Cultivars With and Without Maceration

Cider is often produced from difficult-to-grow heirloom apple cultivars not commonly produced in North America. As such, the value of widely grown dessert apples for fermented cider was explored, with ciders produced from eleven cultivars analyzed. Additionally, the practice of maceration, or fermentation with pomace, was also investigated. Volatile compounds were analyzed by gas chromatography-mass spectrometry. Raw mass spectrometry (MS) data was then followed by an initial untargeted statistical analysis. Principal component analysis of the MS features demonstrated clear separation between cultivars and between maceration effects, prompting further investigation into the compounds impacting cultivar and maceration discrimination. The aroma-active compounds identified are known to elicit sensorial responses often described as sweet, fruity, and floral. Some compounds have been previously identified as primarily apple-derived. While esters and higher alcohols, originating from yeast metabolic activities, were also identified as contributing factors of the observed differences. Despite these compounds being impacted by yeast metabolism, they were highly influenced by cultivar and treatment, indicating apple-derived precursors were, in part, influencing the yeast-mediated aroma differences. ‘Galaxy Gala’ cider samples had the highest overall intensities of quantified volatiles in both years, driven by high eugenol and 1-butanol concentrations. Extended apple pomace maceration did not induce new aromas but increased the content of some compounds. Maceration impact was cultivar dependent, e.g., ethyl 2-methylbutyrate in the ‘Yataka Fuji’ increased 14-fold with maceration but less in other cultivars. This work demonstrates that dessert apples produce ciders with a diversity of aromas that may be further increased via maceration and are worth consideration by producers.

Identification of aroma compounds responsible for apple flavor via palatability score prediction in tree-based regression models

Apple flavor has been linked to the composition of aroma compounds; however, the impact of varying concentrations of aroma compounds remains poorly understood. While sensory evaluation is commonly used to analyze food palatability, assessing the effect of concentration of all aroma compounds poses challenges. This study screened 174 apple genotypes for significant aroma compounds using regression models, Gas chromatography–mass spectroscopy analysis, and sensory palatability scores. Two models viz. Random Forest and XGBoost were employed to predict palatability scores, surpassing the limitations of correlation analysis. Shapley's additive explanatory value analysis identified 5-hexenol, ethyl 2-methyl butyrate, 2-methylbutyl acetate, (E,E)-α-farnesene, and (Z)-3-hexenol as key aroma compounds. In a sensory evaluation validating the effect of aroma compound concentration, the variation in (E,E)-α-farnesene concentration negatively affected sensory palatability scores. This study demonstrated a novel approach for identifying aroma compounds that impact apple flavor, providing valuable insights to enhance apple quality and palatability.

Exploring the Connection between the Occurrence and Intensity of "Grubby" Defect and Volatile Composition of Olive Oil.

In order to investigate the relationship between the occurrence of the "grubby" sensory defect caused by olive fruit fly (Bactrocera oleae (Rossi)) infestation and the resulting volatile composition, virgin olive oils were extracted from olives of the Leccino cultivar with 0%, 50%, and 100% olive fly infestations and subjected to analysis of the basic chemical quality parameters, fatty acids and volatiles, and sensory analysis by the Panel test. A 100% olive fly infestation reduced the basic chemical quality of the oil, while the fatty acid composition was not affected in any case. The overall sensory quality score and intensity of the positive sensory attributes decreased, while the intensity of the "grubby" defect increased proportionally to the degree of infestation. The occurrence and intensity of this defect were clearly causally related to the concentrations of 3-methylbutanal, 2-methylbutanal, β-ocimene, ethyl 2-methylbutyrate, dimethyl sulfoxide, 4-methyl-5H-furan-2-one, α-farnesene, 6-methyl-5-hepten-2-one, 1-octanol, E-2-nonen-1-ol, benzeneacetaldehyde, heptanal, and octanal, implying that the perception of "grubby" comes from their joint contribution to the overall olive oil flavour. In addition to contributing to the understanding of the chemical origin of "grubby", the results obtained could potentially be used to develop strategies to support sensory analysis in the classification of olive oil quality and the confirmation of the presence of this sensory defect in oil samples.

Characterization and comparison of key aroma compounds in traditional and rapid Yongchuan douchi by molecular sensory science

Yongchuan douchi is a famous soybean product that is widely used as a condiment in China due to its attractive aroma and can be categorized into traditional and rapid Yongchuan douchi (TYD and RYD). However, the key aroma compounds in TYD and RYD and their differences remain poorly understood. In the present study, the key aroma compounds in TYD and RYD were characterized and compared by a molecular sensory approach. The results obtained by multidimensional gas chromatography-mass spectrometry/olfactometry (MDGC−MS/O) demonstrated that a total of 125 volatiles and 71 aroma-active compounds were identified. Moreover, 36 aroma-active compounds with relative odor activity values (rOAVs) ≥ 1 and flavor dilution (FD) ≥ 16 were screened and quantified by an external standard method. The recombination and omission experiments revealed that TYD and RYD contained 18 and 13 key aroma compounds, respectively. TYD and RYD contained 10 identical compounds, whereas 8 (ethyl 2-methylbutyrate, ethyl 3-methylbutyrate, ethyl isobutyrate, ethyl caproate, ethyl acetate, ethyl benzoate, 4-methyl-2-phenyl-2-pentenal, acetophenone) and 3 (phenylacetaldehyde, 4-ethyl guaiacol, 4-hydroxy-2,5-dimethyl-3(2H)-furanone) were unique to TYD and RYD, respectively. This is the first report of key aroma compounds in TYD and RYD, and it provides insights into improving the aroma of Yongchuan douchi.

VOCs from fungi-infected apples attract and increase the oviposition of yellow peach moth Conogethes punctiferalis.

Plant volatile organic compounds (VOCs) modified by plant-associated microbes can attract or repel the oviposition of herbivores. Here, we explored the effects of three different fungi on apples' VOCs and the cascading impacts on the oviposition preference of yellow peach moth [YPM, Conogethes punctiferalis (Guenée)]. Among Penicillium crustosum-infected apples (PCA), Rhizopus oryzae-infected apples (ROA), Colletotrichum gloeosporioides-infected apples (CGA) and healthy apples (HA), mated YPM females preferred to oviposit eggs on ROA and CGA, and showed significant attractiveness to VOCs from PCA, ROA, and CGA under laboratory conditions. The VOCs analyses showed that there were significant differences between fungi-infected apples (ROA, CGA) and control treatments (mechanically damaged apples (MDA), HA) in terms of the relative contents of 13 VOCs. The relative contents of ethyl 2-methylbutyrate, ethyl caprylate, estragole, ethyl hexanoate in ROA and CGA were higher than those in MDA. The relative content of isopropyl 2-methylbutyrate in ROA was significantly higher than those in HA and CGA. The relative contents of 2-methylbutyl acetate, butyl 2-methylbutyrate, hexyl 2-methylbutyrate, amyl hexanoate, hexyl hexanoate, (E, E)-α-farnesene in ROA and CGA were lower than those in HA. The relative content of hexyl acetate in ROA and CGA was significantly higher than that in MDA, but lower than that in HA. Additionally, 10 fungi-induced VOCs were detected in ROA and/or CGA. When 20 VOCs from ROA and/or CGA were tested as individuals or mixed blends in Y-tube olfactometer assays, mated YPM females preferred amyl 2-methylbutyrate, isoamyl 2-methylbutyrate, isopropyl 2-methylbutyrate, hexyl propionate (common VOCs in ROA, CGA, and HA), and heptacosane (a fungi-induced VOC in ROA), but no significant preferences were observed between individual compounds and mixed blends, except for hexyl propionate. Different fungi infection increased the relative contents of common VOCs from healthy and fungi-infected apples, which ultimately resulted in the significant attractiveness for the oviposition of mated YPM females. This study clarified why fungi-infected apples were more attractive to YPMs than healthy apples and screened out the crucial VOCs for YPM oviposition. © 2023 Society of Chemical Industry.

Untargeted metabolomic profiling of Aspergillus sojae 3.495 and Aspergillus oryzae 3.042 fermented soy sauce koji and effect on moromi fermentation flavor

Aspergillus sojae 3.495 and Aspergillus oryzae 3.042 are essential microbial starters in fermented foods due to their high hydrolytic enzyme activities. However, their metabolic characteristics and differences during soy sauce fermentation are still unclear. This study identified 42 non-volatile differential metabolites based on UHPLC-MS/MS, among which 10 amino acids and derivatives and 4 non-volatile acids were high in A. sojae 3.495 koji, while 3 sugar alcohols, 5 flavonoids, and 4 fatty acids were prominent in A. oryzae 3.042. Further analysis revealed that higher acidic protease (1887.43 U/g) in A. sojae 3.495 and higher glucoamylase (2413.36 U/g) and cellulase (890.78 U/g) in A. oryzae 3.042 dominated the formation of differential metabolites. Metabolic pathway analysis showed that shikimate and phenylalanine metabolic pathways in A. sojae 3.495 were more active and enhanced 3-methyl-butanal and 2-phenylethanal in moromi fermentation. The more prominent pathways of sugar alcohol metabolism and flavonoid biosynthesis in A. oryzae 3.042 koji enhanced 2-methyl-butanoic acid and ethyl 3-methylbutyrate in moromi and significantly elevated reducing sugars (1.56 g/100 mL). Overall, comparative metabolomics elucidated the metabolic framework and flavor formation mechanisms of different inocula in soy sauce koji, providing ideas for scientific control of soy sauce fermentation and multi-strain koji-making for flavor enhancement.

Sensory dimensions derived from competitive and creative perceptual interactions between fruity ethyl esters and woody odorants in wine-like models

The present study analyses the sensory effects associated with the interactions between different woody aroma compositions and a simple fruity ester vector in red wines. The semi-synthetic wine models contained a fixed aroma composition, the dearomatised non-volatile fraction of red wine and 21 different combinations of ethyl 2-methylbutyrate (fruity vector) plus 1 out of 3 woody aroma compositions (woody vectors) at 3 possible levels of concentration each. Woody vectors imitated a highly toasted American oak (HAO—elevated levels of whiskylactones and furaneol), a highly toasted French oak (HFO—low levels of whiskylactone and vanillin levels, high levels of eugenol and guaiacol) and a medium toasted French oak (MFO—low levels of whiskylactones, eugenol, guaiacol and furaneol and high levels of vanilla). Models were sensorily assessed by a sorting task and by descriptive analysis. The increase in woody notes causes a concomitant decrease in fruity notes by a competitive perceptual interaction. HAO models are richest in coconut and woody notes and poorest in fruity notes, while HFO models keep strawberry and apple notes. At certain specific fruity-woody vector ratios, particularly in the MFO model, blackcurrant notes emerge, which can be considered a creative perceptual interaction.

Introducing a Simple Method to Investigate Relative Volatilities of Flavour Compounds in Fruit Brandies

Determination of relative volatilities of flavour compounds in hydro-alcoholic solutions is usually performed by time-consuming and costly standard methods such as the Gillespie dynamic recirculation method. This study tested a quick and easy method with a simple distillation apparatus for measuring empirical relative volatilities. A total of 17 representative flavour compounds of apple and pear brandies were selected and investigated for their relative volatilities. This also included so far unpublished relative volatilities of one alcohol (2-butanol), one aldehyde (hexanal), one ketone (β-damascenone), and three esters (ethyl butyrate, butyl acetate, ethyl 2-methylbutyrate). Relative volatilities of three alcohols (methanol, isobutanol, and isoamyl alcohol), one ester (ethyl acetate), one aldehyde (acetaldehyde), and one acetal (1,1-diethoxyethane) were compared to reference data. All compounds, except for 1,1-diethoxyethane, showed a high correlation with the reference data. Vapour–liquid equilibrium for an ethanol–water mixture showed a high correlation with the reference data (r &gt; 0.9). In accordance with the high correlation levels, we suggest that the simple distillation apparatus is a fast and simple alternative to the standard method.

Volatile organic compounds (VOC) in homes associated with asthma and lung function among adults in Northern Europe

Associations between measured specific VOC reported to be associated with dampness and microbial growth in dwellings and asthma, lung function were investigated in 159 adults (one adult/home) from three North European cities (Reykjavik, Uppsala and Tartu). Spirometry was performed and forced vital capacity (FVC), forced expiratory volume in 1 s (FEV1) and FEV1/FVC were measured. Among 159 participants, 58% were females, 24.5% atopics, 25.8% current smokers and 41% reported dampness or mold at home. Dimethyl disulphide (p = 0.004), ethyl isobutyrate (p = 0.021) and ethyl 2-methylbutyrate (p = 0.035) were associated with asthma. Isobutanol (p = 0.043), 3-methyl-1-butanol (p = 0.020), 2-hexanone (p = 0.033), 1-octen-3-ol (p = 0.027), 2-methyl-1-butanol (p = 0.022) and 2-ethyl-1-hexanol (p = 0.045) were associated with lower FEV1. Isobutanol (p = 0.004), 3-methyl-1-butanol (p = 0.001), 2-heptanone (p = 0.047) and 2-methyl-1-butanol (p = 0.002) were associated with lower FEV1/FVC. The association between dimethyl disulphide and asthma was more pronounced in females (p for interaction 0.099). The association between 1-butanol and lower FEV1 was more pronounced in males (p for interaction 0.046). The associations between 3-octanone (p for interaction 0.064), 2-ethyl-1-hexanol (p for interaction 0.049) and lower FEV1, and between 2-heptanone (p for interaction 0.021), 3-octanone (p for interaction 0.008) and lower FEV1/FVC were stronger in homes with dampness/mold. Factor analysis identified one VOC factor related to asthma and two VOC factors related to lower lung function. Increased air concentrations of 2-heptanone, ethyl 2-methylbutyrate and ethyl isobutyrate were related to prescence of certain mold species (Aspergillus sp., Cladosporum sp. and Penicillium sp.) or building dampness. Some VOC were associated with type of dwelling, building age and pet keeping. In conclusion, some VOC reported to be associated with dampness and microbial growth can be associated with asthma and lower lung function in adults. Associations between these VOC and respiratory illness can be stronger in homes with dampness/mold. There can be gender differences in respiratory health effects when exposed to indoor VOC.

Çeşitli elmaların aroma bileşikleri ve kalite özellikleri

In this study; quality characteristics and volatile compounds of Starking Delicious, Amasya, Granny Smith, and Golden Delicious apple cultivars were determined. Granny Smith has the highest titratable acidity and the lowest pH value, while the Amasya apple has the highest dry matter and water-soluble solids. Aroma is an important quality criterion for apples and its has a big role in consumer taste. The aroma composition of apples was determined in gas chromatography-mass spectrometry (GC-MS) using the headspace method. Forty different volatile compounds, including 24 esters, 5 higher alcohols, 1 aldehyde, 1 terpene and 9 unidentified volatile compounds, were detected in apples. Esters, which make up 80.00% of Starking Delicious, 76.55% of Amasya and 62.82% of Golden Delicious are the main flavor group in apples and esters generally impart aroma compounds preferred by consumers. Butyl acetate, 2-methyl butyl acetate, hexyl acetate, (E,E)-α-farnecene, ethanol and ethyl 2-methyl butyrate were the aroma components determined at the highest rates in apples. These compounds contribute to the aroma of apples such as banana, fruity, strawberry, sweet, pear, grass and alcohol.

Enhancing blueberry wine aroma: Insights from cultivar selection and berry sorting

This study aimed to improve the aroma quality of blueberry wine by employing cultivar selection and precise berry sorting. We conducted a comprehensive analysis of volatile profiles in blueberry wines derived from nine cultivars commonly cultivated in the middle region of China. ‘Misty’ and ‘V3’ blueberry wines exhibited pronounced floral aromas, closely linked to elevated terpenoid and phenylacetaldehyde content. ‘Legacy’ and ‘Star’ displayed a distinct fruity aroma profile attributed to the presence of ethyl 2-methylbutyrate, ethyl phenylacetate, and diethyl succinate. ‘Jewel’ featured an intense buttery aroma, correlated with higher concentrations of ethyl dodecanoate, ethyl decanoate, and ethyl octanoate. Subsequently, ‘Misty’ and ‘Star’, with distinct aroma profiles, were selected to further unravel the impact of berry size on blueberry wine aroma. The findings revealed that small berries significantly enhanced ‘Misty’ blueberry wines, increasing higher alcohol, ester, and terpenoid content, resulting in a more intense fruity and floral aroma. Interestingly, berry size had no discernible influence on ‘Star’ blueberry wine aroma. This study provides valuable insights into the enhancement of blueberry wine production, shedding light on the intricate interplay of cultivar selection, berry sorting, and their impact on the aromatic attributes of the final product.

A Targeted and an Untargeted Metabolomics Approach to the Volatile Aroma Profile of Young 'Maraština' Wines.

This study investigated the detailed volatile aroma profile of young white wines of Maraština, Vitis Vinifera L., produced by spontaneous fermentation. The wines were produced from 10 vineyards located in two Dalmatian subregions (Northern Dalmatia and Central and Southern Dalmatia). Volatile compounds from the wine samples were isolated by solid-phase extraction (SPE) and analyzed by an untargeted approach using two-dimensional gas chromatography coupled with time-of-flight mass spectrometry (GC×GC/TOF-MS) and a targeted approach by gas chromatography-tandem mass spectrometry (GC-MS/MS). A comprehensive two-dimensional GC×GC analysis detailed the total volatile metabolites in the wines due to its excellent separation ability. More than 900 compounds were detected after untargeted profiling; 188 of them were identified or tentatively identified. A total of 56 volatile compounds were identified and quantified using GC-MS/MS analysis. The predominant classes in Maraština wines were acids, esters, and alcohols. The key odorants with odor activity values higher than one were β-damascenone, ethyl caprylate, ethyl isovalerate, ethyl 2-methylbutyrate, ethyl caproate, isopentyl acetate, ethyl butyrate, and phenylacetaldehyde. The metabolomics approach can provide a large amount of information and can help to anticipate variation in wines or change winemaking procedures.