Gas Chromatography-mass Spectrometry-olfactometry Research Articles

Characterization of key aroma-active compounds in Zanthoxylum schinifolium by sensory evaluation and multiple instrumental analyses

The aroma characteristics of Zanthoxylum schinifolium from four different production areas in Sichuan were identified and compared. Aroma components were analyzed via sensory evaluation, gas chromatography–olfactometry–mass spectrometry (GC–O–MS), and comprehensive two-dimensional gas chromatography-olfactometry-mass spectrometry (GC × GC–O–MS). The results revealed that minty, spicy, woody, fresh, citrus, and herbal notes could be perceived, with the Jinyang sample exhibiting the most significant aroma profile. Compared with GC–O–MS, GC × GC–O–MS offers advantages in identifying aroma-active compounds, and it can identify more types and quantities of aroma-active compounds. In this study, 40 aroma-active compounds from seven different classes were identified via GC × GC–O–MS. Through aroma extraction dilution analysis (AEDA), 14 aroma-active compounds were quantitatively analyzed, and odor activity values (OAVs) were calculated. Additionally, orthogonal partial least squares discriminant analysis (OPLS-DA) was employed to identify four aroma-active compounds with variable importance in projection (VIP) scores greater than 1, indicating their potential as identification markers. This study enhances our understanding of the sensory characteristics and aroma-active compounds of Zanthoxylum schinifolium.

Characterization of key aroma compounds in microgreens and mature plants of hydroponic fennel (Foeniculum vulgare Mill.)

Fennel is a popular culinary herb known for its unique flavor. In this study, we identified key aroma-active compounds in fresh fennel (Foeniculum vulgare Mill.) and its microgreens. Fennel was cultivated hydroponically with soilless substrates. Upon harvesting, samples were ground with liquid nitrogen, and headspace solid phase microextraction (SPME) gas chromatography-mass-spectrometry-olfactometry (GC-MS-O) was used for volatile analysis. Thirty-two and 28 key aroma-active compounds were identified in fennel microgreens and mature leaves, respectively. Phenylpropenes, especially (E)-anethole, were the predominant aroma-active compound in all samples (36.3–83.4 %). Quantitation results showed that fennel microgreens contained a significantly higher amount of monoterpenes, showing an 81.4–98.1 % increase when compared to mature fennel. Principal component analysis (PCA) of identified volatiles indicated a distinctive difference in the overall aroma profile between microgreens and mature leaf. The changes in aroma contents over different growth stages revealed the underlying volatile biosynthesis discrepancy. This study provided baseline information for understanding the aroma evolution from microgreen to mature fennel herbs

Flavor-boosting of Phaeodactylum tricornutum by fermentation with edible mushrooms

Microalgae are a promising and sustainable source of nutritious food, especially for use in alternatives to fish and seafood. Among them, Phaeodactylum tricornutum (PT) stands out for its potential to revolutionize future diets with its rich nutrient profile and eco-friendly cultivation methods. However, its typically fishy and “brackish water” off-odor has been a significant deterrent. Using 13 basidiomycetes as starter cultures, the dynamic changes in the aroma were studied. To better understand the aroma development during fermentation, odor-active compounds were identified using headspace solid-phase microextraction coupled with gas chromatography–mass spectrometry–olfactometry. By submerged fermentation lasting 39 and 51 hours with Pleurotus citrinopileatus (PCI) and Pleurotus eryngii (PER), respectively, the unpalatable odor of PT was transformed into savory and seafood-like aromas, while retaining most of the valuable carotenoids (fucoxanthin and β-carotene were retained at 75 % and 90 %) and fatty acids (eicosapentaenoic acid and docosahexaenoic acid were preserved at 80 % of their initial concentrations). Throughout the fermentation process, key odorants responsible for the algae's initial green, grassy, and unpleasant odor were reduced, while compounds responsible for savory and seafood-like fragrances increased. A series of sulfur compounds, such as dimethyl disulfide, were found to be major contributors to the post-fermentation aroma.

Characterization of Key Aroma Compounds of Soy Sauce-like Aroma Produced in Ferment of Soybeans by Bacillus subtilis BJ3-2.

Fermented soybeans are popular among many for their rich soy sauce-like aroma. However, the precise composition of this aroma remains elusive, with key aroma compounds unidentified. In this study, we screened the candidate genes ilvA and serA in BJ3-2 based on previous multi-omics data, and we constructed three mutant strains, BJ3-2-ΔserA, BJ3-2-ΔilvA, and BJ3-2-ΔserAΔilvA, using homologous recombination to fermented soybeans with varying intensities of soy sauce-like aroma. Our objective was to analyze samples that exhibited different aroma intensities resulting from the fermented soybeans of BJ3-2 and its mutant strains, thereby exploring the key flavor compounds influencing soy sauce-like aroma as well analyzing the effects of ilvA and serA on soy sauce-like aroma. We employed quantitative descriptive sensory analysis (QDA), gas chromatography-olfactometry-mass spectrometry (GC-O-MS), relative odor activity value analysis (rOAV), principal component analysis (PCA), orthogonal partial least squares-discriminant analysis (OPLS-DA), and partial least squares regression analysis (PLSR). QDA revealed the predominant soy sauce-like aroma profile of roasted and smoky aromas. GC-MS detected 99 volatile components, predominantly pyrazines and ketones, across the four samples, each showing varying concentrations. Based on rOAV (>1) and GC-O, 12 compounds emerged as primary contributors to soy sauce-like aroma. PCA and OPLS-DA were instrumental in discerning aroma differences among the samples, identifying five compounds with VIP > 1 as key marker compounds influencing soy sauce-like aroma intensity levels. Differential analyses of key aroma compounds indicated that the mutant strains of ilvA and serA affected soy sauce-like aroma mainly by affecting pyrazines. PLSR analysis indicated that roasted and smoky aromas were the two most important sensory attributes of soy sauce-like aroma, with pyrazines associated with roasted aroma and guaiacol associated with smoky aroma. In addition, substances positively correlated with the intensity of soy sauce-like aroma were verified by additional experiments. This study enhances our understanding of the characteristic flavor compounds in soy sauce-like aroma ferments, provides new perspectives for analyzing the molecular mechanisms of soy sauce-like aroma formation, and provides a theoretical framework for the targeted enhancement of soy sauce-like aroma in various foods.

Impact of Different Wood Types on the Chemical Composition and Sensory Profile of Aged Tsipouro: A Comparative Study

The production of high-quality aged marc spirits includes a minimum period of six months of ageing in oak barrels. Lastly, producers are interested in alternative botanical origin wood. The present study is aimed at investigating the influence of Greek oak (Quercus trojana) and Greek chestnut (Castanea sativa) compared with French (Quercus petraia) and American oak (Quercus alba) on the chemical composition and sensorial characteristics of aged tsipouro, produced from marc from the Black Muscat variety. Gas chromatography–olfactometry–mass spectrometry (GC–O–MS) was used to identify volatile compounds of the aged tsipouro. Also, colour and polyphenol measurements were made, and an organoleptic evaluation was performed by 16 trained tasters. The findings revealed rather similar results between the tsipouro made from different wood species, especially between Greek and French oaks, and relative differentiation for that of chestnut. All the aged distillates exhibited a pleasant and rich aromatic potential, dominated by floral and fruity terpene varietal aromas as well as wood-related volatiles. Chestnut, with a high phenolic potential, gives pleasant organoleptic effects over time and can be an alternative wood for ageing spirits. This research highlights the importance of wood selection in the tsipouro ageing process and enables the use of Greek wood species in the ageing of spirits.

Changes of Potent Odorants in Salted Duck Egg Yolk before and after Roasting.

As the second most widely consumed eggs, duck eggs are made into preserved eggs, salted duck eggs, and roasted duck eggs to extend their shelf-life. To investigate the differences in potent odorants (POs) between salted duck egg yolk (SDEY) and roasted duck egg yolk (RDEY), the volatiles in SDEY and RDEY were extracted through solvent extraction coupled with solvent-assisted flavor evaporation and were assayed with gas chromatography-mass spectrometry-olfactometry. A total of 45 volatiles were identified in two samples, 24 odor-active compounds (OACs) were screened, and more OACs were in RDEY. The flavor-dilution (FD) factors of OACs were obtained by aroma extract dilution analysis and ranged from 3 to 6561. Twenty-two OACs with FD factors ≥ 9 were quantitated, and the results indicated the concentrations of OACs in yolk increased greatly after salted duck eggs were roasted. Based on the concentrations and thresholds, odor activity values (OAVs) were determined; 17 odorants with OAVs ≥ 1 were determined as POs. Acetoin was the most PO in SDEY; there were more POs in RDEY, including 2-ethyl-3,6-dimethylpyrazine, acetoin, 2-acetyl-3-methylthiophene, dihydro-4-hydroxy-2(3H)-furanone, etc. The outcomes obtained have reference values for making better use of duck eggs in the food industry.

Comprehensive foodomics analysis reveals key lipids affect aroma generation in beef

Lipids are vital precursors to beef aroma compounds, but the exact lipid molecules influencing aroma generation remain unconfirmed. This study employs gas chromatography–olfactometry–mass spectrometry and absolute quantitative lipidomics to identify beef's aroma and lipid profiles and to examine lipid alterations post-thermal processing. The aim is to understand the role of lipids in aroma generation during beef's raw-to-cooked transition. Eighteen key aroma compounds were identified as significant contributors to the aroma of beef. 265 lipid molecules were quantified accurately, and we found that triglycerides containing C18:1 or C18:2 chains, such as TG(16:0_18:1_18:1), TG(16:0_18:1_18:2), TG(16:0_16:1_18:1), as well as phosphatidylcholine and phosphatidylethanolamine containing PC(16:1e_20:4), PC(16:0e_20:4), PC(18:2e_18:2), and PE(16:1e_20:4), played important roles in the generation of key aroma compounds in beef. C18:1, C18:2, C18:3, and C20:4 were key substrates for the formation of aroma compounds. In addition, lysophosphatidylcholine and lysophosphatidylethanolamine containing unsaturated fatty acid chains may serve as important aroma retainers.

A Comparative Analysis of Cold Brew Coffee Aroma Using the Gas Chromatography-Olfactometry-Mass Spectrometry Technique: Headspace-Solid-Phase Extraction and Headspace Solid-Phase Microextraction Methods for the Extraction of Sensory-Active Compounds.

Coffee, one of the most widely consumed commodities globally, embodies a sensory experience deeply rooted in social, cultural, and hedonic contexts. The cold brew (CB) method, characterized by cold extraction, is a refreshing and unique alternative to traditional coffee. Despite its growing popularity, CB lacks defined preparation parameters and comprehensive analysis of its aromatic composition. In this study, we aimed to obtain a representative extract of the volatile matrix of CB and characterize the aroma of sensory-active compounds using advanced techniques such as headspace-solid-phase Microextraction (HS-SPME) and headspace-solid-phase extraction (HS-SPE) for volatile compound extraction, followed by gas chromatography-olfactometry-mass Spectrometry (GC-O-MS) for compound identification. Optimization of the HS-SPME parameters resulted in the identification of 36 compounds, whereas HS-SPE identified 28 compounds, which included both complementary and similar compounds. In HS-SPME, 15 compounds exhibited sensory activity with descriptors such as floral, caramel, sweet, and almond, whereas seven exhibited sensory activity with descriptors such as chocolate, floral, coffee, and caramel. This comprehensive approach to HS-SPME and HS-SPE aroma extraction with GC-O-MS offers an efficient methodology for characterizing the aroma profile of CB, paving the way for future research and quality standards for this innovative coffee beverage.

Characterization of the Key Aroma Compounds of Soybean Flavor in Fermented Soybeans with Bacillus subtilis BJ3-2 by Gene Knockout, Gas Chromatography–Olfactometry–Mass Spectrometry, and Aroma Addition Experiments

Characterization of the Key Aroma Compounds of Soybean Flavor in Fermented Soybeans with Bacillus subtilis BJ3-2 by Gene Knockout, Gas Chromatography–Olfactometry–Mass Spectrometry, and Aroma Addition Experiments

Characterisation of aroma‐active compounds in wheat flour by molecular sensory science

SummaryFour different extraction methods were used to extract aroma compounds from flour. It was found that dynamic headspace sampling (DHS) was a better method for extracting aroma‐active compounds in flour. Hexanal, decanal, butanoic acid, 2,3‐pentanedione, 2‐acetyl‐1‐pyrrolinoline, and 3‐octen‐2‐one were found to be the important aroma‐active compounds in flour by olfaction (O) in two‐dimensional gas chromatography–olfactometry–mass spectrometry (GC×GC‐O‐MS). Dynamic headspace dilution analysis (DHDA), odour activity value (OAV), recombination and omission experiment further verified that these compounds can roughly simulate the overall aroma profile of flour. In this study, we determined the aroma‐active compounds in flour by molecular sensory science to improve the sensory preference of flour and enhance the quality of flour aroma, which will provide analytical ideas for future research on flour aroma and improve the production process.

A comparative study to determine the key aroma components of yogurt aroma types based on Sensomics and Flavoromics

This study used Sensomics to examine four previously obtained yogurt aroma type profiles. 14 key aroma-active compounds were identified as significant contributors (p ≤ 0.05) in the four aroma types using gas chromatography–mass spectrometry-olfactometry (GC–MS/O), aroma extract dilution analysis (AEDA), odor activity values (OAV), and aroma recombination and omission experiments. The Sensomics and previous Flavoromics results were compared, showing that Flavoromics identified 10 indicator compounds for distinguishing aroma types. Eight were the same as the key aroma-active compounds identified via Sensomics, namely acetic acid, pentanoic acid, decanoic acid, 3-hydroxy-2-butanone, 2,3-pentanedione, acetaldehyde, δ-decalactone, and dimethyl sulfone. Sensomics revealed a prominent similarity between the categories of key aroma-active compounds of the four aroma types, with a higher sensory contribution. Flavoromics showed less overlapping between the indicator compounds, mainly related to the distinction between the four aroma types. Sensomics and Flavoromics serve distinct research objectives and should be selected according to the study subject.

Examination of the Odor-Eliminating Effect of a Deodorizing Spray on the Volatile Odorants of Malignant Wounds.

This study aimed to compare the odor components before and after spraying a deodorizing spray (DS) on volatile odorants in malignant wounds (MWs) in women with breast cancer; a secondary aim was to evaluate the deodorizing effect of the DS. This is an observational study. We investigated 3 patients who had MWs resulting from breast cancer. Participants were recruited from outpatient clinics in the Breast Surgery Department, University Hospital, Kanagawa, Japan. The target material was exudate-containing dressings collected from MWs. After collection, the odor components (air) were collected into a sampling bag by using a handheld pump. Then, after 5 sprays of a DS, air was collected in the same manner. All odor components were analyzed objectively by gas chromatography-mass spectrometry-olfactometry (GC/MS-O). The concentration in parts per million (ppm) of the main odor components in the air before and after spraying DS was compared, and the residual concentration rate (%) was calculated. Sniffing tests before and after spraying were also conducted to determine the subjective deodorizing effect of DS. Of the possible hundreds of volatile odorants, 3 to 11 main components of volatile odorants were detected per subject. After DS spraying, the odorants dimethyl disulfide, dimethyl trisulfide, and benzyl alcohol were reduced according to GC/MS-O. The residual concentration of the following main odor components was also reduced: benzyl alcohol (30%), octanal (56%), p-dichlorobenzene (56%), isovaleric acid (56%), propylene glycol (63%), and nonanal (66%). DS was effective against some volatile odorants in MWs, but no clear deodorizing effect was observed. Since there are individual differences in the type and number of odorants in MWs, the use of DS needs to be examined and verified in a larger number of cases.

Characterization of the key odorants in Amomum tsao-ko cobs by sensory directed flavor analysis

To decode the key odorants in Amomum tsao-ko cobs (ATC) and to examine the impact of extraction methods on key odorants, volatiles of ATC were isolated by both hydrodistillation (HD) and solvent extraction combined with solvent-assisted flavor evaporation (SE-SAFE). In total, 49 aroma-active compounds with flavor dilution (FD) factors between 1 and 8192 were detected by gas chromatography–olfactometry-mass spectrometry, of which 39 and 42 odorants were identified in the HD and SAFE extracts, respectively. The 34 odorants (FD ≥ 16) were further quantitated; odor activity value calculations, aroma reconstitution and omission experiments were conducted to evaluate their contributions to the characteristic odor of ATC, and 11 compounds were confirmed as key odorants of ATC. Furthermore, the majority of the potent odor-active compounds in the two extracts were identical, but their concentrations were significantly different. The outcomes will give a theoretical foundation for developing and utilizing ATC.

Characterization of flavour components and identification of lipid flavour precursors in different cuts of pork by phospholipidomics

The lipids and volatile compounds in pork from different parts, including the loin, belly, shoulder and hind leg were analyzed by triple quadrupole tandem time-of-flight mass spectrometer (Q-TOF/MS) and gas chromatography-olfactometry-mass spectrometry (GC-O-MS), respectively. Partial least squares regression (PLSR) and Pearson correlation analysis were utilized to establish the relationship between the lipids and volatile compounds. A total of 8 main flavour substances, 38 main phospholipids, and 32 main fatty acids were identified. The results showed that the key flavour compounds were mainly derived from unsaturated fatty acids and phospholipids containing unsaturated fatty acids, including oleic acid (C18:2n6c), α-Linolenic acid (C18:3n3), arachidonic acid (C20:4n6), PE O (18:1/20:4), PE O (18:2/20:4), and PE O (18:2/18:2), etc. Understanding the relationship between flavour compounds and lipids of pork will be helpful to control the quality of pork.

Enzymatic synthesis of pyridine heterocyclic compounds and their thermal stability

An efficient method was discovered for catalyzing the esterification under air using Novozym 435 to obtain pyridine esters. The following conditions were found to be optimal: 60 mg of Novozyme 435, 5.0 mL of n-hexane, a molar ratio of 2:1 for nicotinic acids (0.4 mmol) to alcohols (0.2 mmol), 0.25 g of molecular sieve 3A, a revolution speed of 150 rpm, a reaction temperature of 50 °C, and reaction time of 48 h. Under nine cycles of Novozym 435, the 80 % yield was consistently obtained. Optimum conditions were used to synthesize 23 pyridine esters, including five novel compounds. Among them, gas chromatography-mass spectrometry-olfactometry (GC-MS-O) showed phenethyl nicotinate (3g), (E)-hex-4-en-1-yl nicotinate (3m), and octyl nicotinate (3n) possessed strong aromas. Thermogravimetric analysis (TG) revealed that the compounds 3g, 3m and 3n exhibited stability at the specified temperature. This finding provides theoretical support for adding pyridine esters fragrance to high-temperature processed food.

Characterization and correlations of dominant microorganisms and volatile compounds in fermentation process of Yangjiang douchi.

Yangjiang douchi (YD) is a traditional fermented soybean product, which is popular in Chinese cuisine for its unique flavor. However, due to its high salt content and unstable flavor, its competitiveness in the international market is gradually weakening. Microorganisms have a key role in the production process of YD because it is a fermented food but the effect of microorganisms on the volatile compounds of YD is also not currently clear. In this paper, aroma compounds and microbial diversity in different fermentation stages of YD were analyzed using gas chromatography-mass spectrometry/olfactometry (GC-MS/O) and IlluminaMiseq system sequencing. A total of 78 aroma-active compounds were detected throughout the fermentation process and they influenced the formation of flavor in YD. Fungi flora were relatively single in YD, and bacteria were rich and varied. A total of 418 species of bacteria were present during fermentation, with unclassified_Staphylococcus, Staphylococcus_kloosii, and Bacillus_velezensis_Bacillus predominating. There were 25 species of fungi at the species level, and Aspergillus minisclerotigenes (OTU 4) played a dominant role in the whole fermentation process. Staphylococcus and Bacillus in the bacterial genus were strongly correlated with most flavor compounds detected, and A. minisclerotigenes in the fungi were more relevant to flavor compounds. This research provides a theoretical basis for the enhancement of the flavor of traditional fermented douchi in China. © 2024 Society of Chemical Industry.

Characterization of odor-active compounds in Liuzhou River snail rice noodles soup by sensory-directed flavor analysis

Liuzhou River snails rice noodles, a special snack of Liuzhou City in the Guangxi Zhuang Autonomous Region, China, possess a unique flavor of spicy, refreshing, fresh, sour, and hot. The present study aimed to characterize the composition of volatile compounds and key odor-active compounds in river snails rice noodles soup (RSRNS) through aroma extract dilution analysis and odor activity value calculation using solid-phase microextraction (SPME) combined with comprehensive two-dimensional gas chromatography–olfactometry–mass spectrometry (GC×GC–O–MS) and gas chromatography–olfactometry–mass spectrometry (GC–O–MS). A total of 71 volatile compounds were identified by GC–O–MS, of which 49 were odor-active. Meanwhile, 125 volatile compounds were identified by GC×GC–O–MS, of which 68 were odor-active. These results indicated that 3-methylbutanal, linalool, 1,8-cineole, myrcene, 2-acetylpyrazine, 4-allylanisole, 2-acetylthiazole, 1-octen-3-ol, hexanal, and eugenol were the main odor-active compounds of RSRNS.

Characterization of the key aroma compounds of wild bitter melon lujiu based on LLE coupled with GC–O–MS and the aroma influence of polysaccharide addition using VASE–GC–MS

Wild bitter melon (Momordica charantia L. Var. Abbreviata Ser; WBM) is widely cultivated in East and Southeast Asia. It is made into lujiu with high-quality strong-flavor baijiu and presents a beautiful golden color and harmonious aroma. Lujiu is a type of alcoholic beverage similar to gin. In this study, the aroma profile of wild bitter melon lujiu (WBML) was determined through sensory evaluation, and important aroma-active compounds were identified through liquid–liquid extraction (LLE) coupled with gas chromatography–olfactometry–mass spectrometry (GC–O–MS) and aroma extraction dilution analysis (AEDA). A total of 42 aroma-active compounds were identified, and 28 of them with FD factor ≥ 3 were quantified. Sixteen compounds were pivotal aroma contributors, among which ethyl hexanoate, ethyl pentanoate, ethyl butanoate, ethyl octanoate, and acetic acid had the highest OAVs. Moreover, WBM-sourced aroma compounds were found in WBML, including dihydroactinidiolide, (E,E)-2,4-nonadienal, β-ionone, etc. The extraction parameters of vacuum-assisted sorbent extraction (VASE) were optimized for the first time to analyze lujiu aroma. The effect of homologous polysaccharide addition to the aroma of WBML was explored with VASE–GC–MS. The greasy off-odor was decreased due to the reduction of ethyl octanoate volatility by polysaccharide addition.

Variations in Key Aroma Compounds and Aroma Profiles in Yellow and White Cultivars of Flammulina filiformis Based on Gas Chromatography-Mass Spectrometry-Olfactometry, Aroma Recombination, and Omission Experiments Coupled with Odor Threshold Concentrations.

Flammulina filiformis (F. filiformis) is called the 'benefiting intelligence' mushroom. There is a notable difference between a yellow cultivar (with a robust aroma) and a white mutant cultivar (with a high yield) of F. filiformis. A thorough analysis of aroma differences is essential to improve the aroma of high-yield strains. This study employed a combination of gas chromatography-mass spectrometry-olfactometry (GC-MS-O) and aroma extract dilution analysis (AEDA) to analyze the variations in aroma compounds. Then, the contribution of the odorants was determined using flavor dilution (FD) factors and odor activity values (OAVs). Aroma omission and recombination experiments were used to identify the key odorants. A total of 16 key aroma compounds were characterized in F. filiformis, along with four eight-carbon volatiles (3-octanone, 3-octanol, octanal, and 1-octen-3-ol). Finally, the dominant aroma characteristic was "sweet" for the yellow strain, while it was "green" for the white strain. More research is required to investigate the enzymes and corresponding genes that regulate the synthesis of aroma compounds in F. filiformis for future breeding programs.

Comparison of Aroma Compounds and Sensory Characteristics between Two Different Types of Rice-Based Baijiu.

Rice-based Baijiu has gained popularity in the Chinese market. Qingya-flavored Baijiu, a variant of Xiaoqu-fermented Baijiu, employs rice as its primary raw material, with an improved production process compared to traditional rice-flavored Baijiu. We comprehensively characterized and compared the aroma profiles of these two rice-based Baijiu types using static sensory experiments (QDA, quantitative descriptive analysis) and dynamic sensory experiments (TDS, temporal dominance of sensations). Qingya-flavored Baijiu exhibited pronounced plant, oily, and roasted aromas, while traditional rice-flavored Baijiu displayed more prominent fruity, floral, and sour notes. Utilizing GC-O-MS (gas chromatography-olfactometry-mass spectrometry) and multi-method quantification, we qualitatively and quantitatively analyzed 61 key aroma compounds, identifying 22 compounds with significant aroma contributions based on odor activity values (OAVs). Statistical analyses, combining sensory and chemical results, were conducted to predict important aroma compounds responsible for the aroma differences between the two Baijiu types. Aroma Recombination and Omission experiments showed that seven compounds play key roles in the aroma of Qingya-flavored Baijiu, including (2E,4E)-Deca-2,4-dienal, linalool, apricolin, ethyl acetate, ethyl isobutyrate, ethyl caprylate, and ethyl isovalerate.