Application of electroencephalogram (EEG) in the study of the influence of different contents of alcohol and Baijiu on brain perception.

Alcoholic beverages flavour is complex and unique with different alcohol content, and the application of flavour perception could improve the objectivity of flavour evaluation. This study utilized electroencephalogram (EEG) to assess brain reactions to alcohol percentages (5 %-53 %) and Baijiu's complex flavours. The findings demonstrate the brain's proficiency in discerning between alcohol concentrations, evidenced by increasing physiological signal strength in tandem with alcohol content. When contrasted with alcohol solutions of equivalent concentrations, Baijiu prompts a more significant activation of brain signals, underscoring EEG's capability to detect subtleties due to flavour complexity. Additionally, the study reveals notable correlations, with δ and α wave intensities escalating in response to alcohol stimulation, coupled with substantial activation in the frontal, parietal, and right temporal regions. These insights verify the efficacy of EEG in charting the brain's engagement with alcoholic flavours, setting the stage for more detailed exploration into the neural encoding of these sensory experiences.

Untargeted metabolomics combined with chemometrics reveals distinct metabolic profiles across two sparkling cider fermentation stages.

This study aimed to examine the metabolic profiles of Saccharomyces cerevisiae yeasts (WLS21 and Y41) in two phases of sparkling cider making (normal and pressure fermentation) by combining untargeted metabolomic with chemometrics. The results showed that of the 634 nonvolatile metabolites identified using LC-MS and 83 volatile metabolites identified by GC-MS, the differential metabolites were 226 and 54, respectively. Metabolic pathway and correlation analyses showed that aspartic acid, phenylalanine and tyrosine, glutamic acid and purine metabolism were associated with flavor formation. The pressure fermentation process increased apigenin, naringenin, toxifolin, pyridoxine and thiamine contents in the final cider. These findings provide useful information and new research ideas for the formation of flavor in sparkling cider and the regulation of phenolic and vitamin production by microbial stress fermentation.

Decoding Long-Chain Fatty Acid Ethyl Esters during the Distillation of Strong Aroma-Type Baijiu and Exploring the Adsorption Mechanism with Magnetic Nanoparticles.

Simultaneous detection of the dynamic distribution of long-chain fatty acid ethyl esters (LCFAEEs) during Baijiu distillation is crucial for optimizing its flavor and health attributes. In this study, we synthesized a simple, cost-effective Fe3O4@NH2 adsorbent to simultaneously extract eight LCFAEEs from Baijiu. Through density functional theory and adsorption experiments, we elucidated 1,6-hexanediamine as a surface modifier, with the -NH2 groups providing adsorption sites for the LCFAEEs via hydrogen-bonding interactions and van der Waals forces. Additionally, we established the magnetic solid-phase extraction-GC-MS extraction technique combined with stable isotope dilution analysis to analyze LCFAEEs. This method revealed the dynamic distribution patterns of LCFAEEs during strong aroma-type Baijiu (SAB) distillation. We observed that the concentrations of the eight LCFAEEs gradually decreased with prolonged distillation and were significantly correlated with ethanol concentration. To ensure optimal flavor and clarity in SAB, it is recommended to select the heart-stage base Baijiu with an alcohol content of 58%-63%.

Identification of Two New Taste-Active Compounds in Oak Wood: Structural Elucidation of Potential ß-Methyl-γ-octalactone Precursors and Quantification in Spirits.

Barrel aging is a crucial stage that influences the taste of wines and spirits, particularly increasing their sweetness and bitterness. This increase is caused by nonvolatile compounds released from oak wood. To search for such molecules, we performed a taste-guided inductive fractionation protocol using several analytical techniques. By using HRMS and NMR, two new galloylated derivatives were elucidated. Their enzymatic hydrolysis revealed the formation of ß-methyl-γ-octalactone, indicating that they are potential precursors. The taste properties of these isomers revealed a sweet and bitter taste for P-WL-1 and P-WL-2, respectively. An LC-HRMS quantification method was performed to evaluate the influence of aging parameters such as botanical origin and toasting process on their concentrations. Several spirits were also analyzed to confirm their presence in this matrix. These results improve the understanding of the molecular markers responsible for the taste of beverages.

Assessment of beverage quality for ethyl caproate and procyanidin B2 utilizing binary liposomes.

Procyanidins are bioactive compounds present in fruits like apples. These compounds can be extracted and studied for their functional properties. Within the class of procyanidins, procyanidin B2 (PB2) serves as a standard reference. Sake, a traditional Japanese alcoholic beverage, contains ethyl caproate (EC), which adds economic value to the drink. Analyzing PB2 in apple juice and EC in sake, particularly in simple prepared beverages without the use of organic solvents or in their original state, requires the application of binary liposomes composed of 1,2-dioleoyl-sn-glycero-3-phosphocholine (DOPC) and 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC). In this study, I investigated the size of liposomes and the ratio of solid ordered (So) to liquid disordered (Ld) liposomes. The results indicated that PB2 increased the size of liposomes, while EC decreased it. Additionally, EC influenced the ratio of So/Ld liposomes. These findings provide a foundational understanding for further research on the biophysical and physiological properties of EC and PB2.

Assaying D-Amino Acid in Japanese Sake Using L-Amino Acid Derivatizing Agent.

The D-amino acids of D-alanine, D-glutamic acid, and D-aspartic acid increase tasting evaluation scores of Sake, a Japanese traditional alcohol beverage. Sake is brewed using seed mash for growth of brewing yeast without growth of contaminating microorganisms. Kimoto is brewed using lactic acid bacteria growth to decrease pH. Sake brewed using the Kimoto method also has a rich taste and a higher tasting evaluation score than Sake brewed using the Sokujyo Syubo (Moto) method, which adds lactic acid instead of using lactic acid bacteria growth. D-alanine, D-glutamic acid, and D-aspartic acid in Sake have the function of increasing tasting evaluation scores. They are converted by enzymes in lactic acid bacteria respectively as alanine racemase (EC 5.1.1.1), glutamate racemase (EC 5.1.1.3), and aspartate racemase (EC 5.1.1.13) in Kimoto Mash. Herein, simultaneous assay methods for D-alanine, D-glutamic acid, and D-aspartic acid are explained. Sample solutions adjusted to alkalinity are derivatized by an L-FDLA solution only for L-amino acid. Results demonstrate that, for D-alanine, D-glutamic acid, and D-aspartic acid, this method can assay them easily using no expensive or specialized equipment.

A machine learning-based electronic nose system using numerous low-cost gas sensors for real-time alcoholic beverage classification.

This study introduces numerous low-cost gas sensors and a real-time alcoholic beverage classification system based on machine learning. Dogs possess a superior sense of smell compared to humans due to having 30 times more olfactory receptors and three times more olfactory receptor types than humans. Thus, in odor classification, the number of olfactory receptors is a more influential factor than the number of receptor types. From this perspective, this study proposes a system that utilizes distinctive data patterns resulting from heterogeneous responses among numerous low-cost homogeneous MOS-based sensors with poor gas selectivity. To evaluate the performance of the proposed system, learning data were gathered using three alcoholic beverage groups including different aged whiskeys, Korean soju with 99% same compositions, and white wines made from the Sauvignon blanc variety, sourced from various countries. The electronic nose system was developed to classify alcoholic samples measured using 30 gas sensors in real time. The samples were injected into a gas chamber for 60 seconds, followed by a 60-second injection of clean air. After preprocessing the time-series data into four distinct datasets, the data were analyzed using a machine learning algorithm, and the classification results were compared. The results showed a high classification accuracy of over 99%, and it was observed that classification performance varied depending on data preprocessing. As the number of gas sensors increased, the prediction accuracy improved, reaching up to 99.83 ± 0.21%. These experimental results indicated that the proposed electronic nose system's classification performance was comparable to that of commercial electronic nose systems. Additionally, the implementation of an alcoholic beverage classification system based on a pretrained LDA model demonstrated the feasibility of real-time classification using the proposed system.

Rapid electrochemical detection of L-lactate in Baijiu affecting serotonin and dopamine secretion in mice.

Baijiu, a traditional Chinese alcoholic beverage, carries China's rich historical and cultural heritage. Consumers experience varying levels of relaxation and pleasure after consuming different types of Baijiu, with the biological basis of delectation influenced by serotonin and dopamine. In this study, we prepared carbon fiber electrodes modified with surface decorated gold nanoparticles to directly measure the electrochemical response signals in the serum of mice before and after gavage with different types of Baijiu. It was observed that the serum signal change in mice after consuming Baijiu sample 1 (J1) was higher than that of the other two types of Baijiu. Consequently, trace flavor compounds in the Baijiu samples were detected using gas chromatography-mass spectrometry (GC-MS) and liquid chromatography-mass spectrometry (LC-MS), revealing the highest content of L-lactic acid in J1. Mice were intraperitoneally injected with 200 mg kg-1 of L-lactic acid. The changes in dopamine and serotonin in the serum of the injected mice were monitored using a biosensor, and the results were compared with the results of high performance liquid chromatography-triple quadrupole mass spectrometry (HPLC-MS). The findings confirmed that L-lactic acid could indeed stimulate the secretion of both neurotransmitters in mice, suggesting that the trace components in J1 may even exhibit synergistic effects. This study contributes to a deeper understanding of the effects of Baijiu on the body and provides a scientific basis for the production and consumption of Baijiu.

Lab-made automated parallel-dispersive pipette extraction device for the determination of polycyclic aromatic hydrocarbons in distilled beverages (sugarcane spirits) using HPLC-DAD.

This work describes the development of a new automated parallel dispersive tip microextraction method (Au-Pa-DPX) for the determination of eleven polycyclic aromatic hydrocarbons (PAHs) in four samples of Brazilian sugarcane spirit beverages, with separation and detection done by the HPLC-DAD. The results obtained with the Au-Pa-DPX approach were also compared with those obtained via the conventional parallel manual DPX method with the same samples and optimized extraction process. Desorption solvent and cycles of desorption, cleaning and extraction were optimized using response surface methodology and univariate approaches. For the Au-Pa-DPX method, the coefficient of determination (R2) ranged from 0.9948 to 0.9997. The limits of detection and quantification were all 0.303 µg l-1 and 1.00 µg l-1, respectively. Interday and intraday precision ranged from 7.6 % to 31.7 % and 0.40 % to 15.8 %, respectively. For the manual parallel DPX method, the interday and intraday precision ranged from 8.2 % to 38.1 % and 5.40 % to 18.7 %, respectively. The relative recovery values obtained with the proposed method ranged from 53.29 to 124.94 %. The enrichment factors ranged from 15.13 to 22.35. The sum of PAH concentrations in the four samples ranged from undetected to 25.58 µg l-1. These results, when correlated to other methods, highlight the gains in regards to precision obtained with the automated apparatus. Furthermore, when compared to other methods from the literature, it is an interesting green alternative for the determination of these analytes and this sample, with high throughput (4.67 min per sample), low consumption of solvents and samples, generating less waste and reducing health risks to the analyst.

The insights into sour flavor and organic acids in alcoholic beverages.

Alcoholic beverages have developed unique flavors over millennia, with sourness playing a vital role in their sensory perception and quality. Organic acids, as crucial flavor compounds, significantly impact flavor. This paper reviews the sensory attribute of sour flavor and key organic acids in alcoholic beverages. Regarding sour flavor, research methods include both static and dynamic sensory approaches and summarize the interaction of sour flavor with aroma, taste, and mouthfeel. In addition, this review focuses on identifying key organic acids, including sample extraction, chromatography, olfactometry/taste, and mass spectrometry. The key organic acids in alcoholic beverages, such as wine, Baijiu, beer, and Huangjiu, and their primary regulatory methods are discussed. Finally, future avenues for the exploration of sour flavor and organic acids by coupling machine learning, database, sensory interactions and electroencephalography are suggested. This systematic review aims to enhance understanding and serve as a reference for further in-depth studies on alcoholic beverages.

Decoding of the isotopic fingerprint of tequila 100% agave silver class and image analysis to evaluate differences between spirits.

This communication shows the decoding of Isotopic Fingerprint of Tequila 100% agave silver class (IFTequila100% agave) in three areas corresponding to isotopic variations due to: plant used as raw material, fermentation and distillation process, and hydrolysis process. Isotopic tracers that make them up correspond to the δ13CVPDB ethanol-δ13CVPDB ethyl acetate-δ13CVPDB isoamyl alcohol, δ13CVPDB ethyl acetate-δ13CVPDB isoamyl alcohol-δ13CVPDB n-propanol and δ13CVPDB ethyl acetate-δ13CVPDB n-propanol-δ13CVPDB methanol, respectively. Once the IFTequila100%agave has been decoded, an image comparison was performed against isotopic fingerprints of spirits (Tequila, Bacanora, Raicilla, Sotol, and Mezcal). Results show that it is possible classifies 100% of samples analyzed. Likewise, from decoding it is possible to determine the critical process stage to determine variations with respect to the IFTequila100%agave. The chemometric analysis developed corresponds to an auxiliary analytical tool useful for the inspection processes currently carried out by the authorities to determine the authenticity of the beverage.

One-pot derivatization/magnetic solid-phase extraction combined with high-performance liquid chromatography-fluorescence detection for rapid analysis of biogenic amines in alcoholic beverages.

The determination of biogenic amines (BAs) in alcoholic beverages is crucial for assessing their health impact, ensuring beverage quality, and guaranteeing safety. Herein, a rapid one-pot derivatization/magnetic solid-phase extraction (OPD/MSPE) method was proposed using 6-aminoquinolinyl-N-hydroxysuccinimide carbamate as the derivatization reagent and magnetic hydroxyl-functionalized multi-walled carbon nanotubes as the extraction material. Integration of derivatization and extraction steps simplifies the sample preparation process, taking only three minutes and eliminating the need for centrifugation by utilizing magnetic sorbent. The resulting desorption solution was directly analyzed by high-performance liquid chromatography-fluorescence detection (HPLC-FLD) without any evaporation or reconstitution steps. The integrated OPD/MSPE-HPLC-FLD method demonstrates excellent linearity (R2 > 0.992), accuracy (relative recoveries: 85.1-109.2%), precision (RSDs≤9.7%) and detection limits (limits of detection: 0.3-2 ng/mL). It has been successfully applied to determine free BAs in various alcoholic beverages, including red wine, Baijiu, Huangjiu, and beer. This method enables rapid, sensitive and precise analysis of BAs in alcoholic beverages.

Difference between traditional brewing technology and mechanized production technology of jiangxiangxing baijiu: Micro ecology of zaopei, physicochemical factors and volatile composition.

Mechanized production of Jiangxiangxing Baijiu (JB) stands as a pivotal trend in today's Baijiu industry. This study, employing high-throughput sequencing and headspace solid phase microextraction gas chromatography-mass spectrometry (HS-SPME-GC-MS) technology, comprehensively analyzed the micro ecology, physicochemical factors, and volatile components during pit fermentation, comparing traditional fermentation Zaopei (TZP) and mechanized fermentation Zaopei (MZP). According to the research findings, the dominant microorganisms in the fermentation process of ZP comprise Lactobacillus, Monascus, Issatchenkia, and Zygosaccharomyces. In addition, functional microorganisms like Zygosaccharomyces, Monascus, Issatchenkia, Leiothecium, Candida, Pichia, and others exhibited differences on day 0 and throughout the fermentation process. These differences are attributed to the effects of distinct fermentation environment and physicochemical factors. Furthermore, comprehensive analysis detected 87 volatile compounds in TZP and MZP, with 56 showing significant differences, primarily including alcohols, aldehydes, ketones, acids, esters, and aromatics. Additionally, fermentation can be classified into two phases based on ethanol and volatile compounds production: the initial phase (0-12 days, P1) primarily focuses on alcohols production, while the subsequent phase (12-30 days, P2) concentrates on volatile compounds generation. The subsequent correlation analysis indicates that variations in volatile compounds primarily arise from shifts in microbial composition, with notable differences observed in fungi, specifically Monascus, Zygosaccharomyces, and Issatchenkia, which drive the disparities in volatile compounds. This study provides an important theoretical basis and practical guidance for the realization of mechanized high-quality production of JB.

Scotch Whiskies and Forensic Examinations of Manufacturing-Derived Features for Their Authentication.

With the global whisky market reaching $65.6 billion in 2024 and projected to reach $89.48 billion by the end of 2029, the incentives for fraud in relation to (and adulteration of) this alcoholic beverage are self-evident. Law enforcement agencies worldwide have taken actions against crimes of this nature, with forensic scientists playing crucial roles (mainly through expert testimonies on sample authenticities) during legal proceedings. Important issues associated with Scotch whisky authentication include: (a) understanding the typical manufacturing process; (b) acquisition of reference samples; and (c) effective utilization of instrumentations to characterize features derived from the manufacturing process and strategic approaches for the interpretation of analytical findings. Following a brief review of the definition/classification, manufacturing, and adulteration/counterfeiting of Scotch whiskies, this review focuses on the characterization of manufacturing-derived features and interpretation of analytical findings as grouped into: (a) quantitative analysis of single compounds; (b) qualitative analysis and intensity ratio of multiple compounds; (c) chemometric analysis of selected multi-compounds; and (d) quantitative analysis of selected elements. Finally, a flowchart for conducting the authentication process, from various significantly different perspectives, is proposed.

Impacts of material characteristics on the anaerobic digestion kinetics and biomethane potential of American bourbon and whiskey stillage.

Stillage of American whiskey (e.g., bourbon) manufacturing is an abundant byproduct that is distinguished from fuel ethanol and malt whisky stillage materials by its highly inconsistent nature due to variability in mash bill composition. The impact of stillage physicochemical characteristics on biomethane production through anaerobic digestion was assessed by characterizing American whiskey stillage samples before batch biochemical methane potential tests of whole stillage. A maximum methane yield of 419 Nml CH4/g VS was obtained under food to microbe ratio (F: M) of 0.5 and organic loading rate (OLR) of 10 g VS/L while digester instability was noted under F: M ratios exceeding 0.5 under batch production. Methane production was significantly influenced by the mash bill composition with lowest methane yields obtained with higher rye content (rye whiskey) and highest methane yields obtained with higher corn content (bourbon or corn whiskey). A multiple linear regression model including C, P, N, and Na was able to accurately describe the methane yield (R2 = 0.93). This study provides valuable insights to aid the design of anaerobic digesters generating renewable natural gas from heterogeneous American whiskey stillage.

Comprehensive analysis of risk factors (methanol, acetaldehyde and higher alcohols) in alcoholic beverages and their reduction strategies: GC-MS analysis and modified activated carbon adsorption and characterization.

This study endeavors to examine the levels of risk factors in alcoholic beverages and propose mitigation strategies. GC-MS analysis was utilized to assess risk factors in various distilled-spirits. The content of such risk factors in spirits ranked as follows: vodka ≈ gin < baijiu < whiskey < brandy, and all were adhering to the Chinese national standard. Additionally, a method was refined to alleviate these risks, employing various reagents for activated carbon modification and evaluating their adsorption efficiency for risk factors reduction. Oxalic acid-modified activated carbon exhibited promising adsorption rates for risk factors with acceptable flavor compounds loss, rendering it a prospective solution for health hazard reduction. Characterization via SEM and nitrogen-adsorption-desorption was conducted on the optimal material, complemented by sensory experiments to optimize its application. This study offers valuable insights into the content of risk factors in alcoholic beverages, aiding in improving quality and safety of alcoholic beverages.

Species-level understanding of the bacterial community in Daqu based on full-length 16S rRNA gene sequences.

Daqu is used as the fermentation starter of Baijiu and contributes diversified functional microbes for saccharifying grains and converting sugars into ethanol and aroma components in Baijiu products. Daqu is mainly classified into three types, namely low (LTD), medium (MTD) and high (HTD) temperature Daqu, according to the highest temperatures reached in their fermentation processes. In this study, we used the PacBio small-molecule real-time (SMRT) sequencing technology to determine the full-length 16 S rRNA gene sequences from the metagenomes of 296 samples of different types of Daqu collected from ten provinces in China, and revealed the bacterial diversity at the species level in the Daqu samples. We totally identified 310 bacteria species, including 78 highly abundant species (with a relative abundance >0.1% each) which accounted for 91.90% of the reads from all the Daqu samples. We also recognized the differentially enriched bacterial species in different types of Daqu, and in the Daqu samples with the same type but from different provinces. Specifically, Lactobacillales, Enterobacterales and Bacillaceae were significantly enriched in the LTD, MTD and HTD groups, respectively. The potential co-existence and exclusion relationships among the bacteria species involved in all the Daqu samples and in the LTD, MTD and HTD samples from a specific region were also identified. These results provide a better understanding of the bacterial diversity in different types of Daqu at the species level.

Quantitative determination of vanillin and its detection threshold in sake.

Vanillin is naturally occurring in various food products, including alcoholic beverages; however, its contribution to the aroma of sake is unclear. In this study, an HPLC-MS/MS quantification method was developed and validated by linearity, precision, and recovery, and it was applied to 115 bottles of highly diversified sake. Furthermore, the odor detection threshold of vanillin in sake was determined. Notably, the established method exhibited great linearity (5-1500 µg/L), with a R2 >0.99, and the limit of detection and limit of quantification were 1.7 and 5.5 µg/L, respectively. The spiked recoveries of vanillin ranged from 96.2% to 97.8%, with relative standard deviation ˂ 6.22%. Results revealed trace amounts to 29.9 µg/L of vanillin in the premium young sake, below the detection threshold (78.9 µg/L), whereas aged sake (43 bottles, 3-56 years aging) exhibited varied concentrations from trace amounts to 1727.5 µg/L of vanillin, notably peaking in a 20-year oak barrel-aged sake. The concentration of vanillin in most of the ambient-temperature-aged sake exceeded the detection threshold after 11-15 years of aging. The proposed method facilitates accurate vanillin quantification in sake, crucial for evaluating its flavor impact. Moreover, the discoveries provide a theoretical basis for the sensory exploration of sake aromas and equip the brewing industry with insights for modulating vanillin synthesis during sake aging.

Lignin-based emulsive liquid-liquid microextraction for detecting triazole fungicides in water, juice, vinegar, and alcoholic beverages via UHPLC-MS/MS.

A universal, green, and rapid lignin-based emulsive liquid-liquid microextraction (ELLME) method was established to detect nine triazole fungicides in water, juice, vinegar, and alcoholic beverages via UHPLC-MS/MS. By employing an environmentally friendly emulsifier (lignin), the proposed ELLME was compatible with more extractants, and not restricted to fatty acids. Due to the high amphiphilic properties and three-dimensional structure of lignin, the emulsion was quickly formed through several aspirate-dispense cycles of the green extractant (guaiacol) and lignin solution. And a micropipette was used for rapid microextraction. The limit of detection was 0.0002-0.0057 µg L-1. The extraction recoveries and relative standard deviation were 81.7%-102.0% and 0.9%-7.1%, respectively. Finally, three green metric tools were used to verify the greenness of the whole procedure. The proposed lignin-based ELLME successfully emulsified green solvents, indicating that emerging solvents may be excellent alternatives as extractants in ELLME for pesticide residue analysis in food samples.

Peanut Pairing Baijiu: To Enhance Retronasal Aroma Intensity while Reducing Baijiu Aftertaste.

Liquor-pairing food is a common dietary combination. Baijiu and peanuts are unquestionably a classic pairing in China. But no one has explained why. Its alteration in baijiu flavor was studied using multiple sensory evaluation, as well as nontargeted proton-transfer reaction mass spectrometry coupled with GC × GC-MS. Multiple statistical analyses were used to discover the changes in the retronasal aroma and its contribution to baijiu flavor. It showed that the consumption of peanuts enhances the burst intensity of ester aroma (0.814-1.00) and Jiao aroma (0.889-0.963) but decreases the aftertaste of baijiu (p < 0.05). Meanwhile, it increases the release intensity and advances the burst time of baijiu retronasal aroma (p < 0.05), suppressing its aftertaste through the retention effect of the food matrix, the changes in oral processing, and cross-modal interactions. Hydrophobicity, polarity, and chemical characteristics are key factors of the uneven impact of accompanying food to aroma compounds. Esters, especially ethyl caprylate (2103 ± 927 to 51.9 ± 4.05) is most impacted by peanuts and contributes most to baijiu flavor changes. Pyrazines from peanut enhance the Qu-aroma, grain aroma, and Chen aroma in baijiu flavor. Therefore, we revealed the chemical nature of baijiu-peanut combination and help to optimize baijiu consumption experience.