Search Results (199)

At present, the classification of nongxiangxing baijiu (NXB) predominantly relies on the subjective expertise of distillers and tasters, in the absence of scientifically standardized criteria. This reliance poses challenges for achieving precise classification. Consequently, there is an urgent need to employ flavoromics technology to identify the key characteristic aroma compounds that distinguish different grades of NXB. This study uses sensory evaluation, an electronic nose, and three-dimensional fluorescence spectroscopy to determine the significant differences in aroma profiles among different grades of NXB. Further, 112 compounds were identified by GC-MS, and quantitative analysis was conducted on 33 major volatile compounds. Using odor activity value (OAV) analysis, it found 21, 23, and 26 key aroma compounds (OAV ≥ 1) in Grade 2 (G2), Grade 1 (G1), and prime-grade (GP), respectively. Aroma recombination successfully simulated the aroma distribution of different grades of NXB, and omission experiments identified 11 key aroma compounds as the foundation for NXB. Additionally, each grade exhibited a unique profile of key compounds. G2 was characterized by the presence of octanoic acid, which imparts sweaty and cheesy aromas. G1 contained benzoic acid ethyl ester, phenethyl acetate, pentanoic acid, 2-methyl-1-propanol, and furfural, contributing to sweet, floral, sweaty/cheesy, alcoholic, and roasted aromas. GP demonstrated higher concentrations of aroma compounds compared to G1 and G2, with distinctive compounds such as decanoic acid ethyl ester, dodecanoic acid ethyl ester, 3-methyl-1-butanol, and 1-hexanol, which are associated with sweaty/cheesy, fruity, and alcoholic aromas. This study elucidated the role of these compounds in determining the flavor profiles of various NXB grades, thereby providing a theoretical foundation for the quality grading of NXB. Full article

This study investigated the differences in key volatile organic compounds (VOCs) and flavor characteristics between essential oils (CEOs) from cinnamon bark and leaf. The volatile compounds of essential oils extracted from Cinnamomum cassia (Xijiang) bark (CEOP) and leaf (CEOY) by hydrodistillation were identified using GC-MS. The results showed that the extraction rates of CEOP and CEOY were 1.56% ± 0.02 and 0.83% ± 0.01 (n = 3), respectively. CEOP and CEOY consisted of 45 and 50 compounds, respectively. Odor activity value (OAV) analysis indicated that cinnamaldehyde (OAV = 935), α-caryophyllene (OAV = 77), and borneol (OAV = 4) played key roles in shaping the aroma of CEOP. Meanwhile, cinnamaldehyde (OAV = 849), nerolidol (OAV = 107), and α-caryophyllene (OAV = 58) were the major contributors to the flavor of CEOY. Electronic nose (E-nose) analysis revealed that sensors W5S and W1W were important for detecting aromatic compounds. Sensory evaluation showed that CEOs differed significantly in spicy, floral, and grassy aromas. These differences may be related to the concentrations of compounds such as cinnamaldehyde, α-caryophyllene, and nerolidol, as well as their interactions with olfactory receptors such as OR2W1 and OR1D2. Cinnamaldehyde activates TRPA1 and TRPV1 to elicit the perception of spiciness. Thus, CEOP may be suitable for baked goods, and CEOY may be suitable for ice cream and beverages. In conclusion, this study provides a theoretical foundation for the precise application of CEOs as condiments in food. Full article

As a wine-producing region in China, Xinjiang’s ecological conditions endow grapes with distinctive flavor potential. However, systematic research on volatile compounds in wines from Vitis amurensis Rupr. varieties in this region remains limited. Therefore, wines from four Xinjiang Vitis amurensis varieties (‘Shuanghong’, ‘Zuoyouhong’, ‘Xuelanhong’, and ‘Beibinghong’) were analyzed using high-performance liquid chromatography (HPLC), headspace gas chromatography–ion mobility spectrometry (HS-GC-IMS), electronic nose (E-nose), odor activity value (OAV) calculation, and multivariate analysis. Physicochemical parameters, organic acids, volatile organic compounds (VOCs), and OAVs were determined. Results showed significant differences in physicochemical properties among the varieties, potentially correlating with wine mouthfeel. Beibinghong wine contained the highest total VOC concentration. Among 64 identified VOCs, 37 had OAVs ≥ 1. Multivariate analysis identified 14 key differential volatile compounds (VIP ≥ 1, p < 0.05) responsible for flavor differences between varieties, with each variety exhibiting distinct key compounds. E-nose analysis effectively distinguished the aroma profiles of the four wines. This study elucidates the chemical and volatile compound characteristics of wines from Xinjiang Vitis amurensis varieties, providing a theoretical foundation for research on their flavor profiles. It also aids in selecting Vitis amurensis varieties for cultivation and supports the development of distinctive regional wines in Xinjiang. Full article

Incrocio Bruni 54 is a little-known white grape variety developed in the Marche region (Italy) from a cross between Verdicchio and Sauvignon Blanc to combine aromatic freshness with structure. In light of the growing interest in minor and autochthonous cultivars, this study provides the first comprehensive chemical characterization of the aroma profile of Incrocio Bruni 54 wines. Seventeen commercial wines were analyzed for varietal compounds, such as terpenes, norisoprenoids, volatile thiols, methyl salicylate and its glycosides, and fermentative compounds, including esters, alcohols, acids, phenols, aldehydes, and ketones, using GC-MS/MS and LC-MS/MS. Odor activity value (OAV) calculations revealed an aroma profile dominated by ethyl esters, such as ethyl caproate and isopentyl acetate, β-damascenone, 4-vinylguaiacol, TDN, and the volatile thiols 3MH and 4MMP, imparting fruity, floral, spicy, and tropical notes. Comparison with datasets of 246 Italian monovarietal white wines and related sub-datasets composed of Verdicchio and Lugana showed significantly higher concentrations of 3MH and free methyl salicylate in Incrocio Bruni 54, but markedly lower levels of glycosylated methyl salicylate forms, suggesting a greater expression of this odorant in young wines balanced by a lower potential over aging. These findings highlight the distinctive aromatic fingerprint of Incrocio Bruni 54, combining parental traits with unique sensory potential, and support its knowledge and valorization in wine production. Full article

Volatile organic compounds (VOCs) are critical indicators of the metabolic status of whole-plant maize silage (WPMS). However, the impact of inoculating various strains of fermentation agents on VOC changes has not been systematically explored. This study aimed to determine how inoculation with Lactiplantibacillus plantarum and Lentilactobacillus buchneri modulates the VOC profile and odor of WPMS after 90 days. VOCs were extracted by headspace solid-phase microextraction and analyzed by gas chromatography-mass spectrometry (HS-SPME-GC-MS). Key VOCs were screened using the variable importance in projection (VIP) and substantiated by relative odor activity values (rOAV) and odor descriptions. A total of 82 compounds were identified, including 22 esters, 19 alcohols, 3 acids, 9 aldehydes, 2 ethers, 6 hydrocarbons, 4 ketones, 10 phenols, and 8 terpenoids. L. plantarum enhanced green/fruity odors while strain L. buchneri significantly reduced undesirable phenolic and aldehydic compounds. Six key VOCs influencing the odor of WPMS were selected: 4-ethyl-2-methoxyphenol and benzaldehyde, which contribute smoky, bacon, and bitter almond aromas, and (E)-3-hexen-1-ol, benzyl alcohol, (E, E)-2,4-heptadienal and methyl salicylate, which impart green, fruity, and nutty aromas. These findings highlight the effects and contributions of various strain additives on VOCs in WPMS, providing new theoretical insights for regulating the flavor profile of WPMS. Full article

In this study, inter-brand variations in volatile flavor compound profiles of four lager beers were systematically investigated by integrating sensory evaluation with GC-MS, GC×GC-TOF-MS, and GC-O-MS. A total of 594 volatile compounds were identified, of which 71 with odor activity values (OAV) ≥ 1 were found to contribute directly to aroma expression. Additionally, 59 compounds with taste activity values (TAV) ≥ 1 were identified and may also contribute to taste perception. Furthermore, 53 aroma-active compounds were confirmed through GC-O-MS, providing additional evidence for their sensory contribution. Partial least squares discriminant analysis (PLS-DA), correlation analysis, and flavor addition experiments revealed brand-specific differential flavor compounds. Ultimately, twenty key differential flavor compounds, encompassing esters, alcohols, aromatic compounds, acids, lactones, and others, were confirmed to contribute to fruity, floral, burnt, and sweet notes. Phenethyl alcohol, with concentrations varying from 1377.1 mg/L in QD to 3297.5 mg/L in HR, showed a more than 2.4-fold difference across brands and was strongly associated with fruity (r = 0.553) and floral (r = 0.564) aroma. These compounds acted in combination to shape distinct aroma profiles. This study provides a molecular-level basis for understanding lager beer flavor and offers practical guidance for targeted flavor modulation in brewing. Full article

White tea quality is primarily determined by its chemical composition, which varies significantly among cultivars. This study aimed to elucidate the chemical basis underlying quality differentiation in Baimudan white tea produced from three major Fujian tea cultivars: “Zhenghe Dabaicha” (ZHDB), “Fuan Dabaicha” (FADB), and “Fuding Dahaocha” (FDDH). Headspace solid-phase microextraction coupled with gas chromatography–mass spectrometry (HS-SPME-GC-MS), liquid chromatography–mass spectrometry (LC-MS), and quantitative descriptive analysis (QDA) were employed to characterize volatile compounds, amino acids, and saccharides. Odor Activity Values (OAVs) and Taste Activity Values (TAVs) were calculated to identify key contributors to sensory perception. Results showed that theanine, glutamic acid, asparagine, and serine were the primary contributors to umami taste, especially in ZHDB and FADB. Sweetness differences were largely due to sucrose, serine, and asparagine. OAV analysis further identified 22 critical aroma compounds: methyl salicylate, linalool, and β-ionone predominantly imparted floral notes, while β-ocimene, benzaldehyde, and geraniol enhanced sweet and fruity aromas. In contrast, (Z)-3-hexenol, (Z)-3-hexenal, and (E)-2-hexenal contributed grassy and refreshing characteristics, together defining the unique aroma profiles of each cultivar. This study provides an integrated chemical and sensory framework for understanding white tea quality variation, offering a theoretical basis for targeted flavor modulation. Full article

The persistent issue of odor nuisance poses significant challenges to the sustainable development of livestock farming. While previous studies have primarily focused on individual gas concentrations, a comprehensive understanding of overall odor impact based on human perception remains limited. This study introduces a novel perspective by employing the odor activity value (OAV)—calculated from the ratio of gas concentration to its olfactory threshold—to evaluate the actual odor contribution of various compounds. Through a meta-analysis of data from 123 papers, we systematically assessed odor emission characteristics and mitigation strategies across different manure management stages. The results indicated that ammonia (NH₃) (with maximum concentration of 8056 ppm) and hydrogen sulfide (H₂S) (with maximum concentration of 20,057 ppm) were the most concentrated odor components in the whole manure management links. However, considering the olfactory threshold, trimethylamine (TMA) (with OAVmax 380800), H₂S (with OAVmax 48919512), butyric acid (with OAVmax 801684), and aldehydes (with OAVmax 11707) played major odor-causing roles. Notably, biological methods (83%), covering (77%), and additives (39%) were the most efficient odor mitigation strategies in the barn, manure storage, and manure treatment link, respectively. Therefore, employing the OAV-based approach is crucial for identifying priority pollutants and developing targeted control strategies across different livestock species and management stages, ultimately guiding more effective odor mitigation and healthier cohabitation. Full article

Floral–fruity aroma Pu-erh tea (FFAPET) is highly valued by consumers for its distinctive and appealing fragrance. This study conducted a comprehensive investigation into the volatile components of FFAPET using advanced analytical techniques, including GC-O-MS, GC-MS/MS, aroma recombination, and omission tests. Compared with traditional stale aroma Pu-erh tea, FFAPET exhibited higher levels of alcohols and alkenes. Through GC-O-MS combined with OAV analysis, 10 key active-aroma compounds were identified in representative FFAPET samples. These compounds included (E, E)-2,4-heptadienal, phenylethyl alcohol, geraniol, (E, Z)-2,6-nonadienal, (Z)-4-heptenal, 2-phenethyl acetate, 2,2,6-trimethylcyclohexanone, D-limonene, β-ionone, and linalool, all of which made significant contributions to the development of the characteristic floral–fruity aroma profile. Tests involving aroma recombination and omission further confirmed that seven of these odorants played essential roles in defining the overall aroma of FFAPET. These findings offer valuable theoretical insights for the enhancement and regulation of Pu-erh tea flavor, particularly for the optimization of the floral–fruity aroma characteristics. Full article

In this study, we systematically characterize the volatile and non-volatile flavor profiles of coffee beans. Sensory evaluation demonstrated unique aromatic profiles for each coffee, with Colombia excelling in chocolate and nutty notes, while Bench Maji exhibited pronounced fruity characteristics. Yirgacheffe had a prominent roasted aroma, and Baoshan stood out for its stronger woody and caramel notes. The analysis employed solvent-assisted flavor evaporation (SAFE), gas chromatography–mass spectrometry/olfactometry (GC-MS/O), and high-performance liquid chromatography (HPLC). A total of 85 aroma compounds were identified, with furans, ketones, and pyrazines being the predominant contributors to roasted, nutty, and caramel aromas. Key aroma-active compounds, including furfural, guaiacol, and furaneol, exhibited the highest flavor dilution (FD) factors (up to 2187) and odor activity values, highlighting their pivotal roles in coffee aroma, with 4-vinyl-2-methoxyphenol (OAV = 761 in GL) and furaneol (OAV = 250 in BS) being particularly influential. Recombination and omission experiments validated the significance of these compounds. Non-volatile analysis revealed distinct differences in organic acids and chlorogenic acid content, with Colombia samples showing higher quinic acid levels, likely due to roasting-induced degradation. These findings provide a theoretical basis for understanding coffee flavor diversity and offer insights for quality assessment and origin identification. Full article

Houttuynia cordata is an Asian culinary herb with a characteristic fishy aroma. The most odor-active compounds, which had previously been identified by a comparative aroma extract dilution analysis applied to fresh rhizomes and leaves, were quantitated by GC–MS or GC–FID. Results revealed 23 and 22 compounds with odor activity values (OAVs) > 1, i.e., their concentrations exceeded their odor threshold concentrations, in rhizomes and leaves, respectively. Of these, myrcene (geranium leaf-like) and 3-oxododecanal (metallic, soapy, fishy) showed the highest OAVs. Aroma reconstitution and omission tests revealed that 3-oxododecanal is key to the characteristic fishy note. Results on the effect of tissue disruption suggested that 3-oxododecanal was already present in the intact H. cordata plant and released upon mechanical impact. Full article

Woody raw materials of wood-based panels like fiberboard and particleboard are one of the primary sources of product odor and one of the indicators affecting the comprehensive health risk assessment of wood-based panel products. This study employed Gas Chromatography-Mass Spectrometry-Olfactometry (GC-MS-O) to investigate the odorant composition and odor characteristics, including Total Odor Concentration (TOC), odor intensity (OI), odor activity value (OAV), and risk value (RV), of 22 wood species commonly used in fiberboard and particleboard production in China. This research identified the major odor-active compounds in wood and provided recommendations for selecting wood raw materials suitable for low-odor fiberboards and particleboards produced by integrating RV and toxicity classification data. The results showed that the main compound types influencing wood odor in 22 wood species were predominantly terpenes, aldehydes, and alcohols. Woods of Cinnamomum, Machilus, and Pinus contained a higher number of dominant odor compounds (OAV > 1 and OI ≥ 3). Wood with stronger odor intensity included Cinnamomum, Pinus, Machilus, Bischofia, and Saurauia. The total RV of Cinnamomum, Pinus, Machilus, Cunninghamia, and Bombax wood exceeded one, necessitating special attention when used as raw materials for wood-based panels. Camphor in Cinnamomum and Machilus wood was the most concentrated odorant, followed by 3-Carene in Pinus wood. Odorants with high OAV included Longifolene, δ-Cadinene, Terpinen-4-ol, 2-Nonenal, γ-Terpinene, d-Limonene, 3-methyl-Butanal, Octanal, α-Pinene, Hexanal, D-Camphor, and trans-Calamenene. Odorants with high RV included terpenes, alcohols, aldehydes, and ketones, such as Camphor, 3-Carene, Eucalyptol, α-Terpineol, β-Pinene, α-Santalene, δ-Cadinene, Safrole, Longifolene, and d-Limonene. Focusing on the reduction and control of these odor-active compounds represents a primary approach to mitigating odors in fiberboard and particleboard products. However, addressing health risks associated with product odors requires additional attention to four specific substances: Safrole, Camphor, Eucalyptol, and α-Terpineol. Although the total RV for the five wood species exceeds one, this does not necessarily mean the final wood-based panel product’s RV exceeds one, as it also depends on the influence of the production process. Therefore, further research should be conducted to investigate the effects of various process parameters in wood-based panel production on the odor compounds present in the final panels. From a comprehensive perspective, considering the overall odor characteristics of wood volatiles, all 18 wood species (Salix, Populus, Rhaphiolepis, Ligustrum, Prunus, Fagus, Pterocarya, Firmiana, Celtis, Cunninghamia, Bombax, Bischofia, Ficus, Saurauia, Eucalyptus, Aleurites, Melia, Bridelia) are suitable for the production of low-odor fiberboards and particleboards. Full article

Wood, as the oldest natural polymer composite material on Earth, holds significant importance in the era of carbon neutrality and serves as an irreplaceable core material in the furniture and construction industries. As a primary raw material for furniture, wood-based lignocellulosic boards have drawn increasing consumer attention due to their odor characteristics. In order to achieve the determination of odor compounds in lignocellulose-based panels, this study established a method combining dynamic headspace sampling (DHS), gas chromatography–mass spectrometry (GC–MS), and odor activity value (OAV) analysis. To address the wide concentration range of odor compounds in lignocellulose-based panels, a three-level standard curve was established to meet the detection of odor substances in common lignocellulose-based panels. The favorable conditions for each factor were as follows: sheet-shaped samples, TENAX-TA adsorbent, 20 mL headspace vials, and a split ratio of 25:1. The method demonstrated good linearity within the range of 0.002–15 mg/m³, with recovery rates ranging from 94.74% to 103.44%. The method was applied to analyze commercially available particleboard, fiberboard, and plywood. A total of 33 odor components were detected. The results indicated that aldehyde contributed significantly to the odor of particleboard, acids were the main contributors to the odor of fiberboard, and terpenes dominated the odor of plywood. The established method is suitable for the qualitative and quantitative analysis of odor compounds in lignocellulose-based panels and provides reliable technical support for tracing, identifying, and controlling odors in these materials. Full article

Heyang Fragrance, a traditional incense dating back to the Eastern Han Dynasty (25–220 AD), was recently inscribed on China’s national list of intangible cultural heritage. This study aimed to systematically analyze three variants of Heyang Fragrance (Aicao, Qinqiang, and Jianjia) through integrated methodologies including electronic nose analysis, headspace solid-phase microextraction coupled with gas chromatography–mass spectrometry (HS-SPME-GC-MS), and antimicrobial activity assays. We selected Escherichia coli, Bacillus subtilis, and Candida glabrata for the antimicrobial activity assays. Comparative analysis revealed significant compositional differences between pre- and post-combustion volatile profiles. Upon ignition, sensor response values increased by 50–100% relative to baseline measurements, with sulfides, terpenes, and short-chain alkanes emerging as dominant components. Qinqiang demonstrated the highest odor activity values (OAVs), particularly through carvacrol (OAV = 6676.60) and eugenol (OAV = 2720.84), which collectively contributed to its complex aromatic characteristics. Antimicrobial assessments revealed concentration-dependent efficacy, with Qinqiang exhibiting broad antimicrobial activity against Escherichia coli (11.33 mm inhibition zone) and Bacillus subtilis (15.00 mm), while Jianjia showed maximal effectiveness against Bacillus subtilis (17.67 mm). These findings underscore the dual significance of Heyang Fragrance in cultural conservation and its prospective applications in aroma therapeutic and antimicrobial contexts. Full article

Understanding how leaf maturity affects the flavor attributes of green tea is crucial for optimizing harvest timing and processing strategies. This study comprehensively characterized the flavor profiles of Fudingdabai green teas at three distinct leaf maturity stages—single bud (FDQSG), one bud + one leaf (FDMJ1G), and one bud + two leaves (FDTC2G)—using a multimodal approach integrating electronic nose, electronic tongue, HS-GC-IMS, relative odor activity value (rOAV) evaluation, and machine learning algorithms. A total of 85 volatile compounds (VOCs) were identified, of which 41 had rOAV > 1. Notably, 2-methylbutanal, 2-ethyl-3,5-dimethylpyrazine, and linalool exhibited extremely high rOAVs (>1000). FDQSG was enriched with LOX (lipoxygenase)-derived fresh, grassy volatiles such as (Z)-3-hexen-1-ol and nonanal. FDMJ1G showed a pronounced accumulation of floral and fruity compounds, especially linalool (rOAV: 7400), while FDTC2G featured Maillard- and phenylalanine-derived volatiles like benzene acetaldehyde and 2,5-dimethylfuran, contributing to roasted and cocoa-like aromas. KEGG (Kyoto Encyclopedia of Genes and Genomes) analysis revealed significant enrichment in butanoate metabolism and monoterpenoid biosynthesis. Random forest–SHAP analysis identified 20 key flavor markers, mostly VOCs, that effectively discriminated samples by tenderness grade. ROC–AUC validation further confirmed their diagnostic performance (accuracy ≥ 0.8). These findings provide a scientific basis for flavor-driven harvest management and the quality-oriented grading of Fudingdaibai green tea. Full article