Exploring the Mystery of the Sweetness of Baijiu by Sensory Evaluation, Compositional Analysis and Multivariate Data Analysis

Effects of fermented tea by Aspergillus cristatus on the characteristic aroma and non-volatile components of Jiang-flavor baijiu

BACKGROUND

Fu Brick tea (FBT) extract has been demonstrated to lower blood lipids, protect liver, and prevent obesity. Despite these benefits, there are no products on the market that combine FBT with other foods or beverages.

RESULT

In this study, we developed a novel product by combining FBT with high-alcohol Jiang-flavor baijiu, resulting in FBT-baijiu. High-performance liquid chromatography-mass spectrometry (HPLC-MS) analysis revealed that FBT-baijiu contains health-promoting alkaloids, including eurocristatine (13.60 ± 0.13 mg/L), (-)-neoechinulin A (10.26 ± 0.09 mg/L), neoechinulin D (7.89 ± 0.05 mg/L), variecolorin G (6.94 ± 0.05 mg/L), and echinulin (25.46 ± 0.27 mg/L), which are known to be present in FBT. The aroma compounds of the FBT-baijiu and the base baijiu were analyzed using comprehensive gas chromatography-olfactometry-mass spectrometry (GC-O-MS) technology. The major volatile compounds of two baijiu samples were identified using relative odor activity values (r-OAVs) analysis. The FBT-baijiu showed a significant reduction in ester content, but a remarkable enhancement in aromatic properties. The findings show that combining FBT with baijiu not only offers functional components but also enhances the flavor profile.

CONCLUSION

This study highlights the potential of utilizing FBT as a functional food ingredient or additive, paving the way for the development of new health-promoting products. © 2024 Society of Chemical Industry.

Separation and characterization of sweet compounds in Baijiu by molecular distillation combined with molecular sensory science

Sweetness is a crucial taste component in Baijiu. However, comprehensive research on the sweetness of Baijiu remains limited, and traditional methods for flavor analysis are not well-suited for identifying the sweet compounds. To address this, a multi-stage molecular distillation method, combined with molecular sensory science, was developed to more effectively and scientifically analyze the key sweet compounds in Baijiu. The recovery rates of samples and compounds were 93.8 % ∼ 98.3 % and 81.6 % ∼ 118.3 %. 15 important compounds with a taste dilution factor (TD) value ≥64 were identified through gas chromatography-mass spectrometry (GC-MS) combined with taste dilution analysis (TDA). By calculating their taste activity values (TAV), 10 primary sweet compounds with TAV ≥1 were determined. Further taste recombination and omission experiments confirmed that ethyl hexanoate, ethyl heptanoate, ethyl octanoate, ethyl 2-methylbutyrate, 1-butanol, phenethyl alcohol, and ethyl acetate contribute significantly to Baijiu's sweetness and are identified as the key sweet compounds.

Sensory Lexicon Construction and Quantitative Descriptive Analysis of Jiang-Flavor Baijiu

Jiang-flavor Baijiu (JFB) is one of the most complex and representative types of traditional Chinese liquor, known for its unique flavor, which is popular among Chinese consumers. Previous studies primarily focused on detecting and identifying volatile compounds but lacked comprehensive descriptions and precise differentiation of their sensory qualities. To explore the sensory characteristics of JFB, this study collected widely recognized sensory descriptors from literature, standards, free descriptive questionnaires, and Pivot Profile experiments, which were then textually analyzed and merged to yield 88 sensory descriptors. M-value and multivariate statistical methods were then used to narrow these down to 35 sensory descriptors, for which corresponding definitions and physical references were established, forming a sensory lexicon for JFB. A quantitative descriptive analysis (QDA) was performed on JFB samples using the sensory lexicon. To ensure the reliability of the analysis, the panel's performance was also evaluated. Hierarchical cluster analysis (HCA), radar plots, and one-way analysis of variance (ANOVA) demonstrated that the established sensory lexicon accurately reflects the sensory profile of JFB and can be used to differentiate the sensory characteristics of samples from different price ranges or regions. This study opens new avenues for the standardization of quantitative descriptive analysis for JFB and provides a case study for constructing sensory lexicons for other types of Baijiu in China.

The influence of different geographical origins and grades on the flavor of Qingxiangxing Baijiu: An integrated analysis using descriptive sensory evaluation, GC×GC-MS, E-nose, and ICP-MS

The origin and grade are the important factors that influence the flavor and price of Qingxiangxing Baijiu (QXB). As the grade increased, sensory differences and geographical differences become more pronounced. The aromas of floral, fruity, and sweet become more noticeable, while the acidity decreased. The different substances among three grades of QXB mainly focused on esters and alcohols. Correlation analysis indicated that the increase in the concentration of ester compounds was one of the reasons for the significant differences in floral, fruity, and sweet fragrances. Because of the higher concentration of acidic compounds in northern QXB, its acidic taste was more pronounced. Meanwhile, the esters and ketones in southern QXB accounted for a higher proportion, which made its floral and fruity fragrance more prominent. PLS-DA was more suitable for the classification of QXB based on grade and region. And the metal elements in QXB could be used for regional identification.

Study on the differentiation of sensory quality of mainstream Jiang-flavor baijiu in the Chinese market based on Pivot Profile

Jiang-flavor baijiu (JFB) is a prominent type of Chinese baijiu, known for its unique flavor attributes, sensory experience, and high tasting value. Previous research has mainly focused on the detection and identification of its flavor substances, but in-depth studies on the precise sensory description and differentiation of its flavor qualities are still lacking. In this study, a rapid sensory analysis method, Pivot Profile (PP), was applied to 30 mainstream JFBs in the Chinese market, generating 91 sensory attributes with independent definitions, from which 29 main sensory attributes were established that were easy to perceive and descriptive, as well as convenient for transmitting their sensory qualities and distinguishing differences in price and production region, including color (one descriptor), aroma (21 descriptors), taste, and mouthfeel (seven descriptors). The nine key sensory attributes that distinguish JFB quality are as follows: Jiang, Grain, Chen, Qu, Rancid, Acid, Sweet, Fullness, and Harmony. It was found that price was positively correlated with sensory quality, with greater variation in the quality of samples within the medium price range (RMB 500-1000). All samples from MTCQ1 (the core production area of Maotai Town) performed better in sensory quality. In addition, salted vegetable showed a high degree of regional characteristics, concentrated in most of the production regions of Guizhou Province. Aroma attributes were more suitable than taste and mouthfeel as sensory indicators for distinguishing production regions. This study has opened the direction of systematic construction of sensory description of JFB and provided a successful case for the evaluation of Chinese baijiu using novel sensory analysis techniques.

Effects of storage time on flavor characteristics of bran-free fermented Baijiu by using electronic sensory, descriptive sensory analysis, GC × GC-MS, and ICP-MS

By examining and analyzing bran-free fermented Baijiu (BFB) with varying storage periods (0-20 years), it was observed that the overall concentration of volatile compounds initially increases and subsequently decreases over time. Furthermore, BFB exhibited more kinds of long chain esters, higher concentration of acetals, and reduced furfural content. The process of cellaring can enhance the aged, sweet, and fruity aroma of BFB. 16 flavor compounds, including 1,1-diethoxyethane, ethyl dodecanoate, and ethyl hexadecanoate, can be used as markers for vintage BFB, and electronic sensory technology was capable of discerning BFB in different years. The results of redundancy analysis (RDA) showed a positive correlation between metals and aldehydes, esters, and ketones, while indicating a negative correlation with acids and alcohols. Al, Fe, and Ca underwent the most significant changes during storage period, and they were positively correlated with differential substances, such as benzaldehyde, vanillin, ethyl isovalerate, and ethyl palmitate (P < 0.01).

A Comparative Analysis of Aroma Profiles of Soju and Other Distilled Spirits from Northeastern Asia

The soju (Korean traditional distilled liquor) market is increasing worldwide. However, in contrast to well-explored distilled liquors, including baijiu (China) and shochu (Japan), soju is less investigated, with limited research on its aroma characteristics. To facilitate better understanding of the aroma characteristics of soju, this study aims to overview recent research on the flavor characteristics of soju and compare data with those of baijiu and shochu, well-established products in the market. Soju is generally made using rice and nuruk (a traditional Korean fermentation starter). Previous studies have reflected that the aroma characteristics vary with raw materials' nutrition percentages, microbial taxa influenced in fermentation starters, and/or pressure reduction during distillation. The research on the aroma characteristics of baijiu, characterized by solid-state fermentation involving qu (a traditional Chinese fermentation starter), is focused on differences in regional characteristics of the flavor type. Research on the aroma characteristics of shochu has primarily demonstrated that the microbial community could contribute significantly to the development of specific aromatic compounds and/or attributes. Moreover, the association of the aroma characteristics of baijiu and shochu with their volatile compound development by the determination of selective ingredients has been examined. Understanding the current research progress can potentially facilitate the improvement in the aroma characteristics of soju.

A novel organic acids-targeted colorimetric sensor array for the rapid discrimination of origins of Baijiu with three main aroma types

Given the severe problem of Baijiu authenticity, it is essential to discriminate Baijiu from different origins quickly and effectively. As organic acids (OAs) are the most dominant taste-imparting substances in Baijiu, we proposed a simple, fast, and effective OAs-targeted colorimetric sensor array based on the colorimetric reaction of 4-aminophenol (AP)/4-amino-3-chlorophenol (ACP) under oxidation of Cu(NO3)2 for the rapid discrimination of origins of Baijiu with three main aroma types. Hydrogen ions ionized from OAs induced the protonation of the amino group, which blocked the colorimetric reaction, and the different levels of OAs in Baijiu enabled the array to discriminate different origins of Baijiu. The array was implemented to analyze 10 simple OAs and 16 mixed OAs and further for the discrimination of 42 Baijius with an accuracy of 98%. This method provided an efficient research strategy for a basis for rapid quality analysis of Baijiu.

Organic-Acid-Sensitive Visual Sensor Array Based on Fenton Reagent-Phenol/Aniline for the Rapid Species and Adulteration Assessment of Baijiu

Baijiu is an ancient, distilled spirit with a complicated brewing process, unique taste, and rich trace components. These trace components play a decisive role in the aroma, taste, and especially the quality of baijiu. In this paper, the redox reaction between the Fenton reagent and four reducing agents, including o-phenylenediamine (OPD), p-phenylenediamine (PPD), 4-aminophenol (PAP), and 2-aminophenol (OAP), was adopted to construct a four-channel visual sensor array for the rapid detection of nine kinds of common organic acids in baijiu and the identification of baijiu and its adulteration. By exploiting the color-changing fingerprint response brought by organic acids, each organic acid could be analyzed accurately when combined with an optimized variable-weighted least-squares support vector machine based on a particle swarm optimization (PSO-VWLS-SVM) model. What is more, this novel sensor also could achieve accurate semi-quantitative analysis of the mixed organic acid samples via partial least squares discriminant analysis (PLSDA). Most importantly, the sensor array could be further used for the identification of baijiu with different species through the PLSDA model and the adulteration assessment with the one-class partial least squares (OCPLS) model simultaneously.

Using in situ untargeted flavoromics analysis to unravel the empty cup aroma of Jiangxiang-type Baijiu: A novel strategy for geographical origin traceability

"Empty cup aroma" is an important characteristic and quality evaluation standard of Jiangxiang-type Baijiu (JXB). In this study, an in situ detection method for the empty cup aroma of JXB was established, and the authenticity and origin information of JXB were identified with an untargeted flavoromics strategy. The complex composition of JXB leads to slow ethanol volatilization, which is a potential method for identifying artificial JXB. The results of the sensory analysis showed that acidic, sauce, burnt and qu in the empty cup of JXB were the strongest at the 45 min stage. A total of 155 compounds were detected in the empty cups of 15 JXB from different regions during 45 min of standing, and 34 compounds were identified as key aroma compounds in the empty cups of JXB. Eleven potential markers were screened (VIP > 1), which can be used to distinguish JXB produced in Guizhou/Sichuan and other regions.

Association between Baijiu chemistry and taste change: Constituents, sensory properties, and analytical approaches

Typical flavors, such as sourness, sweetness, and bitterness, possess numerous functions and physiological significance, and are closely related to Baijiu production management, quality control, and product development. However, current research on Baijiu flavor primarily focuses on the volatile constituents and distinctive aroma compounds. Furthermore, studies on taste substance recognition, identification, and formation are remain in the preliminary phase. Herein, we take an integrated account of the signal transduction, recognition, composition, and sensory properties of the three main basic tastes of Baijiu, including sourness, sweetness, and bitterness. Moreover, to elucidate the factors that might influence the taste perception of Baijiu, we also discussed the biotic and abiotic factors within the fermentation system. Finally, further elucidating the contribution underlying the three main tastes in Baijiu using a combination of the "Sensomics" and "Flavoromics", will allow for Baijiu taste characteristics to be manipulated.

Integration of Chemometrics and Sensory Metabolomics to Validate Quality Factors of Aged Baijiu (Nianfen Baijiu) with Emphasis on Long-Chain Fatty Acid Ethyl Esters

The storage process of Baijiu is an integral part of its production (the quality undergoes substantial changes during the aging process of Baijiu). As the storage time extends, the flavor compounds in Baijiu tend to undergo coordinated transformation, thereby enhancing the quality of Baijiu. Among them, long-chain fatty acid ethyl esters (LCFAEEs) were widely distributed in Baijiu and have been shown to have potential contributions to the quality of Baijiu. However, the current research on LCFAEEs in Baijiu predominantly focuses on the olfactory sensation aspect, while there is a lack of systematic investigation into their influence on taste and evaluation after drinking Baijiu during the aging process. In light of this, the present study investigates the distribution of LCFAEEs in Baijiu over different years. We have combined modern flavor sensory analysis with multivariate chemometrics to comprehensively and objectively explore the influence of LCFAEEs on Baijiu quality. The results demonstrate a significant positive correlation between the concentration of LCFAEEs and the fruity aroma (p < 0.05, r = 0.755) as well as the aged aroma (p < 0.05, r = 0.833) of Baijiu within a specific range; they can effectively reduce the off-flavors and spicy sensation of Baijiu. Furthermore, additional experiments utilizing a single variable suggest that LCFAEEs were crucial factors influencing the flavor of Baijiu, with Ethyl Palmitate (EP) being the most notable LCFAEE that merits further systematic investigation.

Chinese Baijiu and Whisky: Research Reservoirs for Flavor and Functional Food

Baijiu is a traditional spirit with high reputation in the Chinese community, and whisky, on the other hand, is a renowned spirit in Western culture, with both contributing a major proportion to the consumption and revenue in the global spirit market. Interestingly, starting with similar raw materials, such as grains, diverse production methods lead to different organoleptic profiles. In addition, such enormous attention they attract renders them as a crucial part in food and the related industry. Therefore, great efforts are made in improving product quality and optimizing production processes, such as flavor enhancement, facility development, and deep utilization of byproducts. Given the huge impacts and great involvements of these spirits in the general food industry, research focusing on either spirit is of referential significance for other relevant fields. With the aim of facilitating such collaboration, this review discusses the current research status, in a comparative manner, of both spirits in respect to key production processes-oriented sensory and flavor analysis, deep utilization of byproducts, and spirit-derived functional food investigations. Finally, the internal correlations based on the abovementioned criteria are identified, with research prospects proposed.

Characterization of the differences in aroma-active compounds in strong-flavor Baijiu induced by bioaugmented Daqu using metabolomics and sensomics approaches

Bioaugmenting Daqu is an effective strategy to improve the quality of Baijiu, but its effect on overall flavor profiles and aroma-active compounds is unknown. Here, 168 volatiles were determined from fresh strong-flavor Baijiu (SFB) and bioaugmented Daqu increased their diversity and altered the flavor characteristics. Among 49 odorants identified by aroma extraction dilution analysis, 29 aroma-active compounds had odor activity values ≥1, of which 18, 8, and 3 components exhibited the highest content in the SFB fermented by fortified-, space- and conventional-Daqu, respectively. The contribution of increasing ethyl hexanoate and decreasing ethyl lactate of fresh SFB by bioaugmented Daqu was confirmed, and their content changed from 4650 and 1890 mg/L (conventional-SFB) to 6680 and 1760 mg/L (fortified-SFB) and 6130 and 1710 mg/L (space-SFB). Meanwhile, the discriminators among different samples were determined by multivariate statistical analysis. These findings are beneficial for the optimization and improvement of Baijiu aroma.

Comparison of the Aroma-Active Compounds and Sensory Characteristics of Different Grades of Light-Flavor Baijiu

This study comprehensively characterized and compared the aroma differences between four different grades of Fenjiu (FJ, the most representative light-flavor Baijiu). Aroma-active compounds were analyzed by liquid-liquid extraction (LLE) coupled with gas chromatography-olfactometry-mass spectrometry (GC-O-MS). A total of 88 aroma-active compounds were identified, and 70 of them were quantified. The results showed that a majority of aroma compounds in high-grade FJ had higher aroma intensities and concentrations. Among these compounds, there were 28 compounds with odor activity values (OAVs) greater than one in all four wines, which indicated that they might contribute to the characteristic aroma of FJ. Temporal dominance of sensation (TDS) and quantitative descriptive analysis (QDA) were used to characterize the sensory differences. The results suggested that high-grade FJ had a rich, pleasant and lasting retronasal aroma perception and exhibited pleasant orthonasal aroma of floral, fruity, sweet and grassy. Partial least squares regression (PLSR) analysis effectively distinguished four kinds of FJ and revealed associations between the orthonasal aroma attributes and the aroma compounds with OAVs >1. There were 15 compounds with variable importance in projection (VIP) values >1, and they were considered potential aroma markers for quality prediction.

Array-based sensing and discrimination of segmented Baijiu using organic molecules-regulated PEI@Ag NPs@Ln as fluorescent probes

Quickly discriminating different segmented Baijiu can directly control its grade and indirectly affect the quality of the finished Baijiu. A fluorescence sensor array was constructed based on PEI-terminated silver nanoparticles and lanthanide metal ions (PEI@Ag NPs@Ln). Ag NPs were stably dispersed in the PEI-woven network, initially accompanied by excellent fluorescence signals. Organic molecules disrupted the PEI structure and dragged the Ag NPs out. The free Ag NPs sintered or aggregated with the diffusion, resulting in fluorescence quenching. The three lanthanide ions speed up the process, allowing different organic molecules to exhibit more distinct signals. Thus, this sensor was used to map 11 organic molecules' fingerprints and to discriminate segmented Baijiu. The whole process takes only 2 min. With the assistance of pattern recognition, segmented Baijiu from three cellars were successfully discriminated. Fast, effective and simple are highlights, which opens up its practical application potential in the detection field.

Analysis of the Effect of Mixed Fermentation on the Quality of Distilled Jujube Liquor by Gas Chromatography-Ion Mobility Spectrometry and Flavor Sensory Description

Distilled jujube liquor is an alcoholic beverage made from jujube, which has a unique flavor and a sweet taste. The purpose of this study was to explore the effect of mixed fermentation on the quality of distilled jujube liquor by comparing the performance of mixed fermentation between S. cerevisiae, Pichia pastoris and Lactobacillus. The results showed that there were significant differences in the quality of the jujube liquor between the combined strains. Moreover, Lactobacillus increased and P. pastoris reduced the total acid content. The results from an E-nose showed that the contents of methyl, alcohol, aldehyde, and ketone substances in the test bottle decreased significantly after decanting, while the contents of inorganic sulfide and organic sulfide increased. Fifty flavor compounds were detected, including nineteen esters, twelve alcohols, seven ketones, six aldehydes, three alkenes, one furan, one pyridine, and one acid. There were no significant differences in the type or content of flavor compounds. However, PLS-DA showed differences among the samples. Eighteen volatile organic compounds with variable importance in projection values > 1 were obtained. There were sensory differences among the four samples. Compared with the sample fermented with only S. cerevisiae, the samples co-fermented with Lactobacillus or with P. pastoris had an obvious bitter taste and mellow taste, respectively. The sample fermented by all three strains had a prominent fruity flavor. Except for the sample fermented with only S. cerevisiae, the jujube flavor was weakened to varying degrees in all samples. Co-fermentation could be a valuable method to improve the flavor quality of distilled jujube liquor. This study revealed the effects of different mixed fermentation modes on the sensory flavor of distilled jujube liquor and provided a theoretical basis for the establishment of special mixed fermentation agents for distilled jujube liquor in the future.

Machine learning based age-authentication assisted by chemo-kinetics: Case study of strong-flavor Chinese Baijiu

The aged Chinese liquor, Baijiu, is highly valued for its superior organoleptic qualities. However, since age-authentication method and aging-mechanism elucidation of Baijiu is still in the exploratory stage, high-quality aged Baijiu is often replaced by lower-quality, less-aged product with fraudulent mislabeling. Authentic high-quality strong-flavor Baijiu was analyzed by gas chromatography-mass spectrometry. Total esters decreased with aging, while acids, alcohols, aldehydes, ketones, terpenes, pyrazines increased. Although concentrations of partial compounds showed non-monotonic profiling during aging, a close positive linear correlation (R² = 0.7012) of Baijiu Evenness index (0.55-0.59) with aging time was observed, indicating a more balanced composition in aged Baijiu. The reaction quotient (Qc) of each esterification, calculated by the corresponding reactant and product concentration, approached to the corresponding thermodynamic equilibrium constant Kc. This result demonstrated that the spontaneous transformation driven by thermodynamics explained part of the aging compositional profiling. Furthermore, an aging-related feature selection and an age-authentication method were established based on three models combined with five ranking algorithms. Forty-one key features, including thirty-six compound concentrations, four esterification Qc values and the Evenness index were selected out. The age-authentication based on neural network using forty-one input features accurately predicted the age group of Baijiu samples (F1 = 100 %). These findings have deepened understanding of the Baijiu aging mechanism and provided a novel, effective approach for age-authentication of Baijiu and other liquors.

“Key Factor” for Baijiu Quality: Research Progress on Acid Substances in Baijiu

Baijiu is the national liquor of China, which has lasted in China for more than 2000 years. Abundant raw materials, multi-strain co-fermentation, and complex processes make the secrets of baijiu flavor and taste still not fully explored. Acid substances not only have a great influence on the flavor and taste of baijiu, but also have certain functions. Therefore, this paper provides a systematic review for the reported acid substances, especially for their contribution to the flavor and functional quality of baijiu. Based on previous studies, this paper puts forward a conjecture, a suggestion, and a point of view, namely: the conjecture of “whether acid substances can be used as ‘key factor’ for baijiu quality “; the suggestion of “the focus of research on acid substances in baijiu should be transferred to evaluating their contribution to the taste of baijiu”; and the view of “acid substances are ‘regulators’ in the fermentation process of baijiu”. It is worth thinking about whether acid substances can be used as the key factors of baijiu to be studied and confirmed by practice in the future. It is hoped that the systematic review of acid substances in baijiu in this paper can contribute to further in-depth and systematic research on baijiu by researchers in the future.

Quick classification of strong-aroma types of base Baijiu using potentiometric and voltammetric electronic tongue combined with chemometric techniques

Nowadays, the classification of strong-aroma types of base Baijiu (base SAB) is mainly achieved by human sensory evaluation. However, prolonged tasting brings difficulties for sommeliers in guaranteeing the consistency of results, and may even cause health problems. Herein, an electronic tongue (E-Tongue) combined with a gas chromatography-mass spectrometry (GC-MS) method was successfully developed to grade high-alcoholic base SAB. The E-tongue was capable of identifying base SAB samples into four grades by a discriminant function analysis (DFA) model based on human sensory evaluation results. More importantly, it could effectively and rapidly predict the quality grade of unknown base SAB with an average accuracy up to 95%. The differences of chemical components between base SAB samples were studied by the GC-MS analysis and 52 aroma compounds were identified. The qualitative and quantitative results showed that with the increase of base SAB grade, the varieties and contents of aroma compounds increased. Overall, the comprehensive analysis of E-tongue data and GC-MS results could be in good agreement with human sensory evaluation results, which also proved that the newly developed method has a potential to be a useful alternative to the overall quality grading of base Baijiu.

Chinese Baijiu: The Perfect Works of Microorganisms

Chinese Baijiu is one of the famous distilled liquor series with unique flavors in the world. Under the open environment, Chinese Baijiu was produced by two solid-state fermentation processes: jiuqu making and baijiu making. Chinese Baijiu can be divided into different types according to the production area, production process, starter type, and product flavor. Chinese Baijiu contains rich flavor components, such as esters and organic acids. The formation of these flavor substances is inseparable from the metabolism and interaction of different microorganisms, and thus, microorganisms play a leading role in the fermentation process of Chinese Baijiu. Bacteria, yeasts, and molds are the microorganisms involved in the brewing process of Chinese Baijiu, and they originate from various sources, such as the production environment, production workers, and jiuqu. This article reviews the typical flavor substances of different types of Chinese Baijiu, the types of microorganisms involved in the brewing process, and their functions. Methods that use microbial technology to enhance the flavor of baijiu, and for detecting flavor substances in baijiu were also introduced. This review systematically summarizes the role and application of Chinese Baijiu flavor components and microorganisms in baijiu brewing and provides data support for understanding Chinese Baijiu and further improving its quality.

Uncover the Flavor Code of Roasted Sesame for Sesame Flavor Baijiu: Advance on the Revelation of Aroma Compounds in Sesame Flavor Baijiu by Means of Modern Separation Technology and Molecular Sensory Evaluation

Baijiu occupies an important position in the food industry of China and is deeply recognized as the national liquor of China. According to the flavor characteristics, Baijiu is artificially divided into 12 categories. The sesame flavor of Baijiu was accidentally discovered after the founding of the People's Republic of China. Sesame flavor Baijiu is known for its special aroma of roasted sesame, which attracts people's attention. Modern flavor extraction, separation technology, and flavor analysis technology, greatly promote the identification and evaluation of trace components and aroma compounds in Baijiu. Of note, it has successfully identified which aroma compounds are responsible for the special roasted sesame aroma in sesame flavor Baijiu. On this basis, this paper summarizes the extraction methods, detection techniques, analysis methods, aroma expression, and sensory evaluation methods that have been applied for the verification and evaluation of trace components and aroma compounds in Baijiu. More specifically, the research progress on the revelation of aroma compounds in sesame flavor Baijiu is systematically summarized. Next, people will focus on the changing mechanisms of aroma compounds and the metabolic regulation in Baijiu during brewing, which will be helpful for industrialization and the modern production of Baijiu.