Sensory characterization of Baijiu pungency by combined time-intensity (TI) and temporal dominance of sensations (TDS)

Application of multiple dynamic sensory techniques to N-lauroyl amino acids: Exposing the relationship between taste-enhancing properties and chemical structure

This study investigated the taste enhancing effects of N-lauroyl amino acids, including N-lauroyl-phenylalanine, N-lauroyl-tryptophan and N-lauroyl-tyrosine. Sensory results obtained through TDS, TCATA, and TI assessments indicated that all N-Lau-AAs significantly increased the umami intensity and duration of solutions such as simulated chicken broth. Moreover, these compounds masked bitter taste, with LTR showing the most pronounced reduction of bitterness. LP had the effect of enhancing saltiness, whereas LTR and LTY diminished saltiness. Structural analysis revealed a correlation between the chemical structure of N-Lau-AAs and their sensory properties. The presence of carbon‑carbon double bond (CC) was positively correlated with umami intensity and negatively correlated with bitter and salty parameters. Phenolic hydroxyl groups (OH) were negatively correlated with umami intensity and positively correlated with a decrease in bitterness intensity and duration. Overall, this study provides valuable insights into the taste enhancement potential of N-Lau-AAs as taste enhancers in the food industry.

Studies on inhibition of α-glucosidase using debittered formulation of Bacopa monnieri juice: Enzyme inhibition kinetics, interaction strategy, and molecular docking approach

Bacopa monnieri juice (BMJ) is traditionally used, reported, and scientifically validated for memory enhancement. However, its efficacy against diabetes is less explored. The extreme bitterness of BMJ restricts its commercial applications. This study investigates the reduction of bitterness of BMJ followed by evaluation for its α-glucosidase inhibitory activity. Initially, debittering of 30 % (v/v) BMJ using ZnSO4 (15 mM) was optimized by time-intensity analysis and molecular docking of ZnSO4 as well as bacoside A3, the main active compound in BMJ, with TAS2R14 taste receptor. The study indicated 5 hydrogen bonds to be involved in binding with bacoside A3 with binding energy of -11.82 Kcal/mol, while hydrogen bond, salt bridges and metal complexes were involved in binding of ZnSO4 with binding energy of -6.65 Kcal/mol. Subsequently, BMJ, ZnSO4 and BMJ + ZnSO4 (debittered juice) were also found to be potent inhibitors of α-glucosidase in dose-dependent manner. These inhibitors showed parabolic mixed inhibition of α-glucosidase, altered the secondary structure, and quenching of fluorescence. In silico studies revealed hydrogen bonding and hydrophobic interactions between inhibitors and α-glucosidase with lowest binding energy of -15.53 and -7.54 Kcal/mol being recorded for bacoside A3 and ZnSO4, respectively. Molecular docking of other bioactive compounds in BMJ such as apigenin, luteolin, quercetin and bacopasaponin C also showed lower binding energy than the standard drug, acarbose (-5.84). This study inferred the binding of bacoside A3 at the active site of α-glucosidase and of ZnSO4 with other sites on the protein. The study proposes a debittered BMJ formulation to control hyperglycemia.

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.

From Traditional to Intelligent, A Review of Application and Progress of Sensory Analysis in Alcoholic Beverage Industry

Sensory analysis is an interdisciplinary field that combines multiple disciplines to analyze food qualitatively and quantitatively. At present, this analysis method has been widely used in product development, quality control, marketing, flavor analysis, safety supervision and inspection of alcoholic beverages. Due to the changing needs of analysis, new and more optimized methods are still emerging. Thereinto, intelligent and biometric technologies with growing attention have also been applied to sensory analysis. This work summarized the sensory analysis methods from three aspects, including traditional artificial sensory analysis, intelligent sensory technology, and innovative technologies. Meanwhile, the application sensory analysis in alcoholic beverages and its industrial production was scientifically emphasized. Moreover, the future tendency of sensory analysis in the alcoholic beverage industry is also highlights.

Exploration of carbonyl compounds in red-fleshed kiwifruit wine and perceptual interactions among non-volatile organic acids

Carbonyl compounds are vital constituents that contribute to the flavor profile of alcoholic beverages. We examined 3-nitrophenylhydrazine as a derivatizing reagent for the measurement of 34 carbonyl compounds using UPLC-MS/MS. Adding formic acid and sodium acetate to the mobile phase significantly enhanced the detection limit of carbonyl compounds. The technique exhibited a notable extraction efficiency, yielding recovery percentages ranging from 83.6% to 117.1%, coupled with exceptional sensitivity, as evidenced by detection limits spanning from 0.07 μg/L to 4.80 μg/L. The relative standard deviation was <6.9%, indicating the precision and reliability of the analytical methodology. The method was verified by analyzing carbonyl compounds from red-fleshed kiwifruit wine. Furthermore, sensory assessment revealed that the amalgamation of tartaric acid, malic acid, and citric acid contributes to sour taste perception at sub-threshold concentrations through an additive interaction with supra-threshold non-volatile organic acids such as lactic acid and acetic acid.

Multiple effects of spicy flavors on neurological diseases through the intervention of TRPV1: a critical review

The spicy properties of foods are contributed by various spicy flavor substances (SFs) such as capsaicin, piperine, and allicin. Beyond their distinctive sensory characteristics, SFs also influence health conditions and numerous studies have associated spicy flavors with disease treatment. In this review, we enumerate different types of SFs and describe their role in food processing, with a specific emphasis on critically examining their influence on human wellness. Particularly, detailed insights into the mechanisms through which SFs enhance physiological balance and alleviate neurological diseases are provided, and a systematic analysis of the significance of transient receptor potential vanilloid type-1 (TRPV1) in regulating metabolism and nervous system homeostasis is presented. Moreover, enhancing the accessibility and utilization of SFs can potentially amplify the physiological effects. This review aims to provide compelling evidence for the integration of food flavor and human health.

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.

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.

Multi-attribute temporal descriptive methods in sensory analysis applied in food science: A systematic scoping review

Among descriptive sensory evaluation methods, temporal methods have a wide audience in food science because they make it possible to follow perception as close as possible to the moment when sensations are perceived. The aim of this work was to describe 30 years of research involving temporal methods by mapping the scientific literature using a systematic scoping review. Thus, 363 research articles found from a search in Scopus and Web of Science from 1991 to 2022 were included. The extracted data included information on the implementation of studies referring to the use of temporal methods (details related to subjects, products, descriptors, research design, data analysis, etc.), reasons why they were used and the conclusions they allowed to be drawn. Metadata analysis and critical appraisal were also carried out. A quantitative and qualitative synthesis of the results allowed the identification of trends in the way in which the methods were developed, refined, and disseminated. Overall, a large heterogeneity was noted in the way in which the temporal measurements were carried out and the results presented. Some critical research gaps in establishing the validity and reliability of temporal methods have also been identified. They were mostly related to the details of implementation of the methods (e.g., almost no justification for the number of consumers included in the studies, absence of report on panel repeatability) and data analysis (e.g., prevalence of use of exploratory data analysis, only 20% of studies using confirmatory analyses considering the dynamic nature of the data). These results suggest the need for general guidelines on how to implement the method, analyze and interpret data, and report the results. Thus, a template and checklist for reporting data and results were proposed to help increase the quality of future research.

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.

Identifying Umami Peptides Specific to the T1R1/T1R3 Receptor via Phage Display

Umami peptides are small molecular weight oligopeptides that play a role in umami taste attributes. However, the identification of umami peptides is easily limited by environmental conditions, and the abundant source and high chromatographic separation efficiency remain difficult. Herein, we report a robust strategy based on a phage random linear heptapeptide library that targets the T1R1-Venus flytrap domain (T1R1-VFT). Two candidate peptides (MTLERPW and MNLHLSF) were readily identified with high affinity for T1R1-VFT binding (KD of MW-7 and MF-7 were 790 and 630 nM, respectively). The two peptides exhibited umami taste and significantly enhanced the umami intensity when added to the monosodium glutamate solution. Overall, this strategy shows that umami peptides could be developed via phage display technology for the first time. The phage display platform has a promising application to discover other taste peptides with affinity for taste receptors of interest and has more room for improvement in the future.

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.

A Timely Application-Temporal methods, past, present, and future

Eating is a dynamic experience, and temporal sensory methods have been proposed to document how products change over the course of consumption or use (nonfood). A search of online databases yielded approximately 170 sources related to temporal evaluation of food products that were compiled and reviewed. This review summarizes the evolution of temporal methodologies (past), offers guidance in selecting appropriate methods (present), and provides insights into the future of temporal methodologies in the sensory space. Temporal methods have evolved to document a variety of characteristics in food products including how the intensity of a specific attribute changes over time (Time-Intensity), which specific attribute is dominant at each time during evaluation (Temporal Dominance of Sensations), which attributes are present at each time point during evaluation (Temporal Check-All-That-Apply), and many others (Temporal Order of Sensations, Attack-Evolution-Finish, and Temporal Ranking). In addition to documenting the evolution of temporal methods, this review considers the selection of an appropriate temporal method based on the objective and scope of research. When choosing a temporal method, researchers should also consider the selection of panelists to perform the temporal evaluation. Future temporal research should focus on validation of new temporal methods and explore how methods can be implemented and improved to add to the usefulness of temporal techniques for researchers.

Identification of Compounds Contributing to Trigeminal Pungency of Baijiu by Sensory Evaluation, Quantitative Measurements, Correlation Analysis, and Sensory Verification Testing

Pungency is one of the most important mouthfeel characteristics that is primarily related to the sensory quality of distilled spirits. However, the chemical basis of pungency is still unclear. A set of Baijiu samples with different levels of pungency was characterized by sensory analysis and volatile compound analyses. Several esters, aldehydes, and acids significantly correlated with pungency. Ethyl hexanoate, ethyl acetate, 3-methylbutyl hexanoate, acetaldehyde, acetal, and 3-methylbutanal were confirmed to be the strongest contributors to the pungency of Baijiu by the two-alternative forced-choice test. Sensory recombination testing further revealed that the contribution of esters to pungency was much higher than that of the aldehydes, and acid compounds at low concentrations suppress the pungency perception. In this study, the importance of esters in the pungency of distilled spirits is first reported. The results provide an instructive basis for further research into optimizing the quality of products.

Analysis of Pungency Sensation Effects from an Oral Processing, Sensorial and Emotions Detection Perspective—Case Study with Grilled Pork Meat

Pungency is an interesting sensory stimulus analyzed from different perspectives, in particular the underpinning mechanisms of its sensation and perception. In this study, grilled pork meat coated with three types of hot sauces were investigated regarding its main food oral processing characteristics and evaluated using time-intensity and temporal dominance of pungency sensations methods analyzing the pungency descriptors and intensities. Besides these methods, facial expressions obtained from video capturing were subject to emotion detection. Mastication parameters showed a slight, but not statistically significant, trend of an increased number of chews and consumption time associated with pungency intensity, while saliva incorporation indicated an increasing trend depending on the pungency intensity, especially after 25 strokes and before swallowing. Both time intensity and temporal dominance of pungency sensations showed that the complexity of understanding these sensations is in relation to intensity and type. Finally, the use of emotion detection software in analyzing the faces of panelists during mastication confirmed the increase in non-neutral emotions associated with the increase in pungency intensity.