This study aimed to clarify the molecular basis of bitter peptides in lager beer and their impacts on multidimensional sensory attributes of beer body.A systematic workflow was established that included peptide identi...This study aimed to clarify the molecular basis of bitter peptides in lager beer and their impacts on multidimensional sensory attributes of beer body.A systematic workflow was established that included peptide identification by reversed-phase liquid chromatography-quadrupole time-of-flight mass spectrometry(RPLC-QTOFMS),machine learning screening,receptor docking with the bitter taste receptor TAS2R14,molecular mechanics/generalized Born surface area(MM/GBSA)analysis and single-peptide addition tests.Under stringent criteria(-10logP≥15 for database hits and de novo ALC≥90%),2056 peptides were identified;their sequences were enriched in aromatic and branched hydrophobic residues,and most peptides contained three to five amino acids.Machine learning and docking showed that the overall mean docking score was about-6.77,with tripeptides and tetrapeptides performing best(about-7.37 and-6.90,respectively).The ten top candidates displayed docking scores dominated by aromatic and Pro-containing motifs,and their MM/GBSAΔGbind values ranged from about-134 to-82 kcal/mol.The best-scoring peptide HCLPY gave a docking score of about-10.14,and the stability of HCLPY,SFIPLI and AWIQP was mainly supported by van der Waals and lipophilic terms,consistent with binding in a hydrophobic cavity.By combining interaction patterns with binding-pocket geometry,four peptides(SFIPLI,AWIQP,YVGW and HCLPY)were selected as representative bitter peptides.Sensory evaluation showed that,at a constant bitterness level of the control beer(4.8 on a 0-10 scale),singlepeptide addition led to bitterness intensities of 4.95,4.75,4.45 and 4.25 for HCLPY,SFIPLI,YVGW and AWIQP,respectively(p>0.05),but markedly redistributed other flavor dimensions.Relative to the control,hop aroma increased by+33.3%to+74.1%and aftertaste was extended by up to+12.7%.These results indicated flavor redistribution through cross-modal integration and modulation at the oral interface rather than simple additive bitterness.Overall,the work shifted the simple assumption that stronger binding necessarily produced stronger bitterness toward a framework in which molecular binding led to perceptual reweighting and redistribution of overall flavor,and it proposed short,sequence-designed peptides as controllable inputs for flavor engineering.展开更多
The key aroma compounds of five yeast extracts(YE)were identified comprehensively by solvent-assisted flavor evaporation(SAFE),simultaneous distillation extraction(SDE)and solid-phase microextraction(HS-SPME)combined ...The key aroma compounds of five yeast extracts(YE)were identified comprehensively by solvent-assisted flavor evaporation(SAFE),simultaneous distillation extraction(SDE)and solid-phase microextraction(HS-SPME)combined with sensomics approach and convolutional neural network(CNN)framework.The results found 349 volatiles via three methods,with 51 in common,highlighting their combined importance.Forty-nine aroma compounds(FD factor>27)were identified by aroma extract dilution analysis,of which 40 had OAV≥1.Five YEs contained 34,26,16,27,and 27 key aroma compounds respectively,sharing only seven:δ-dodecalactone,2,5-dimethylpyrazine,2-ethyl-6-methylpyrazine,dimethyl trisulfide,indole,benzaldehyde,and 2-methoxyphenol.Additionally,unique key aroma-active compounds for Y2 wereγ-undecalactone,2,3-diethylpyrazine and 2-naphthalenol,and for Y1,Y4 and Y5 were 2-formylpyrrole,4-methyl-pentanoic acid andα-angelica lactone.Roasted and meaty aromas originated from pyrazines,lactones and phenols were prominent sensory attributes of YE.The CNN model showed great fitting and prediction capabilities(91%training set accuracy,82%validation set accuracy at the 50th epoch),reflecting aroma characteristics of YE,with high similarity to results of OAV analysis results.This research combined different extraction methods with sensomics approach and CNN,providing profound insights into YE aroma compounds and thus helping to production of YEs with desirable aroma profiles.展开更多
The aleurone layer(AL)of rice is rich in aroma compounds and their precursors,holding substantial promise as a natural flavor enhancer in cereal-based products.This study aimed to investigate the flavor-improving effe...The aleurone layer(AL)of rice is rich in aroma compounds and their precursors,holding substantial promise as a natural flavor enhancer in cereal-based products.This study aimed to investigate the flavor-improving effect of adding AL to fermented rice cake(FRC),a traditional Chinese fermented food.A total of 58 aroma-active compounds were identified by gas chromatography-olfactometry(GC-O)and aroma extract dilution analysis(AEDA).Sensory analysis revealed that AL addition significantly enhanced popcorn-like,caramel,green,fatty,and cooked bran-like odors.Quantitative analysis and odor activity value(OAV)calculations showed that most odorants exhibited increased OAVs after AL addition,with 2-acetyl-1-pyrroline(2-AP),a key popcorn-like odorant,showing the most pronounced increase(four-fold).After adding AL,the contents of alcohols,alde-hydes,ketones,acids,and lactones in FRC all increased.Orthogonal Partial Least Squares Discriminant Analysis(OPLS-DA)and univariate statistical analysis identified six differential compounds.Among which 2-AP was mainly derived from direct transfer from AL,while other changes were associated with alterations in amino acid,organic acid,and lipid metabolism during fermentation.Aroma recombination experiments further confirmed that 2-AP,2-phenylethanol,3-methylbutanol,1-octen-3-ol,and dihydro-5-pentyl-2(3H)-furanone were key contributors to the overall aroma profile of AL FRC.These findings demonstrate that AL addition effectively enhances the aroma quality of FRC,laying the groundwork for subsequent research into AL's potential to improve the flavor of grain products.展开更多
Bitter gourd(fruit of Momordica charantia L.)is a popular vegetable and medical herb known for its intense bitter taste.However,its major bitter-tasting compounds have not been fully characterized.This study aimed to ...Bitter gourd(fruit of Momordica charantia L.)is a popular vegetable and medical herb known for its intense bitter taste.However,its major bitter-tasting compounds have not been fully characterized.This study aimed to decode its bitterness by application of the sensomics approach.Combining solvent extraction,sensory analysis-guided fractionation and purification with medium-pressure liquid chromatography and high-pressure liquid chromatography,nine bitter-tasting cucurbitane-type triterpenoids were isolated from bitter gourd.The structures of isolated compounds were determined by high-resolution mass spectrometry and nuclear magnetic resonance spectroscopy.The bitter taste recognition thresholds of isolated compounds were in the range from 1.4 mg/L((23E)-3β-O-malonyl-7β,25-dihydroxycucurbita-5,23-dien-19-al,9)to 19.1 mg/L(yeojooside C,5)in 3%ethanol as determined by trained human assessors.Quantification with UPLC-MS/MS demonstrated their natural concentrations in bitter gourd fruits were in the range between 14.2±0.9 mg/kg(yeojooside C,5)and 245.6±22.1 mg/kg(3-O-malonylmomordicine I,10)on a dry weight basis.Calculation of the dose-over-threshold(DoT)factors showed three compounds,namely 3-O-malonylmomordicine I(10),momordicine I(3),and(23E)-3β-Omalonyl-7β,25-dihydroxycucurbita-5,23-dien-19-al(9)were the bitter principles in bitter gourd fruits.On the other hand,momordicoside K(2),which had been known as a bitter principle of bitter gourd for more than forty years,had been proven to be an extraction and isolation artifact rather than a natural component of the plant.Besides,an acid-catalyzed isomerization reaction in the side chain of cucurbitane was discovered,which might explain the formation mechanism of many cucurbitane-type triterpenoids from bitter gourd.展开更多
The aroma compounds of semi-sweet white wines(WWs)with different alcohol by volume(WW1 and WW2:8.5%vol;WW3 and WW4:11.5%vol)were compared.A total of 80 aroma compounds were identified by comprehensive two-dimensional ...The aroma compounds of semi-sweet white wines(WWs)with different alcohol by volume(WW1 and WW2:8.5%vol;WW3 and WW4:11.5%vol)were compared.A total of 80 aroma compounds were identified by comprehensive two-dimensional gas chromatography-time-of-flight mass spectrometry-olfactometry(GC×GC-TOFMS-O).Among these,esters(n=34),terpenes(n=18),and alcohols(n=14)constituted the predominant aroma compounds.Ester contents were significantly higher in the WW1 and WW2(8.5%vol),whereas terpenes and alcohols were more abundant in the WW3 and WW4(11.5%vol).Additionally,ethyl 3-methylbutanoate,ethyl octanoate,and ethyl 3-hydroxybutanoate exhibited higher flavor dilution factors(>243).Based on headspace gas chromatography-ion mobility spectrometry(HS-GC-IMS),the methyl hexanoate and isoamyl acetate as characteristic markers for 8.5%vol WWs,while linalool andβ-pinene for 11.5%vol WWs.The tropical fruity,honey,floral,and citrus-like aromas were dominant in 8.5%vol WW,while citrus,wine,and spice-like aromas were dominant in 11.5%vol WWs.Esters impart fruity and floral aromas,while terpenes are primarily responsible for citrus notes based on sensomics.Based on flavoromics analysis,a total of 19 differential aroma compounds with variable importance in projection(VIP)higher than 1.This study elucidated the relationship between alcohol by volume and aroma profile by employing integrated multi-omics methodologies,thereby providing valuable guidance for the processing of semi-sweet WW.展开更多
基金supported by the Beijing Elite Scientist Sponsor-ship Program of BAST(No.BYESA.2023055)the National Key Research and Development Program of China(No.2022YFD2101205)+1 种基金Research Foundation for Youth Scholars of Beiiing Technology and Business University(JRFYS2025)the National Natural Science Foundation of China(No.32322068).
文摘This study aimed to clarify the molecular basis of bitter peptides in lager beer and their impacts on multidimensional sensory attributes of beer body.A systematic workflow was established that included peptide identification by reversed-phase liquid chromatography-quadrupole time-of-flight mass spectrometry(RPLC-QTOFMS),machine learning screening,receptor docking with the bitter taste receptor TAS2R14,molecular mechanics/generalized Born surface area(MM/GBSA)analysis and single-peptide addition tests.Under stringent criteria(-10logP≥15 for database hits and de novo ALC≥90%),2056 peptides were identified;their sequences were enriched in aromatic and branched hydrophobic residues,and most peptides contained three to five amino acids.Machine learning and docking showed that the overall mean docking score was about-6.77,with tripeptides and tetrapeptides performing best(about-7.37 and-6.90,respectively).The ten top candidates displayed docking scores dominated by aromatic and Pro-containing motifs,and their MM/GBSAΔGbind values ranged from about-134 to-82 kcal/mol.The best-scoring peptide HCLPY gave a docking score of about-10.14,and the stability of HCLPY,SFIPLI and AWIQP was mainly supported by van der Waals and lipophilic terms,consistent with binding in a hydrophobic cavity.By combining interaction patterns with binding-pocket geometry,four peptides(SFIPLI,AWIQP,YVGW and HCLPY)were selected as representative bitter peptides.Sensory evaluation showed that,at a constant bitterness level of the control beer(4.8 on a 0-10 scale),singlepeptide addition led to bitterness intensities of 4.95,4.75,4.45 and 4.25 for HCLPY,SFIPLI,YVGW and AWIQP,respectively(p>0.05),but markedly redistributed other flavor dimensions.Relative to the control,hop aroma increased by+33.3%to+74.1%and aftertaste was extended by up to+12.7%.These results indicated flavor redistribution through cross-modal integration and modulation at the oral interface rather than simple additive bitterness.Overall,the work shifted the simple assumption that stronger binding necessarily produced stronger bitterness toward a framework in which molecular binding led to perceptual reweighting and redistribution of overall flavor,and it proposed short,sequence-designed peptides as controllable inputs for flavor engineering.
基金supported by National Key Research&Development Program of China(2021YFD2100105)School-Enterprise Cooperation Project(2023-4201-13-000901).
文摘The key aroma compounds of five yeast extracts(YE)were identified comprehensively by solvent-assisted flavor evaporation(SAFE),simultaneous distillation extraction(SDE)and solid-phase microextraction(HS-SPME)combined with sensomics approach and convolutional neural network(CNN)framework.The results found 349 volatiles via three methods,with 51 in common,highlighting their combined importance.Forty-nine aroma compounds(FD factor>27)were identified by aroma extract dilution analysis,of which 40 had OAV≥1.Five YEs contained 34,26,16,27,and 27 key aroma compounds respectively,sharing only seven:δ-dodecalactone,2,5-dimethylpyrazine,2-ethyl-6-methylpyrazine,dimethyl trisulfide,indole,benzaldehyde,and 2-methoxyphenol.Additionally,unique key aroma-active compounds for Y2 wereγ-undecalactone,2,3-diethylpyrazine and 2-naphthalenol,and for Y1,Y4 and Y5 were 2-formylpyrrole,4-methyl-pentanoic acid andα-angelica lactone.Roasted and meaty aromas originated from pyrazines,lactones and phenols were prominent sensory attributes of YE.The CNN model showed great fitting and prediction capabilities(91%training set accuracy,82%validation set accuracy at the 50th epoch),reflecting aroma characteristics of YE,with high similarity to results of OAV analysis results.This research combined different extraction methods with sensomics approach and CNN,providing profound insights into YE aroma compounds and thus helping to production of YEs with desirable aroma profiles.
基金supported by the National key research and development program of China(Project Nos.2022YFD2100301,2022YFD2100302 and 2025YFF1107702).
文摘The aleurone layer(AL)of rice is rich in aroma compounds and their precursors,holding substantial promise as a natural flavor enhancer in cereal-based products.This study aimed to investigate the flavor-improving effect of adding AL to fermented rice cake(FRC),a traditional Chinese fermented food.A total of 58 aroma-active compounds were identified by gas chromatography-olfactometry(GC-O)and aroma extract dilution analysis(AEDA).Sensory analysis revealed that AL addition significantly enhanced popcorn-like,caramel,green,fatty,and cooked bran-like odors.Quantitative analysis and odor activity value(OAV)calculations showed that most odorants exhibited increased OAVs after AL addition,with 2-acetyl-1-pyrroline(2-AP),a key popcorn-like odorant,showing the most pronounced increase(four-fold).After adding AL,the contents of alcohols,alde-hydes,ketones,acids,and lactones in FRC all increased.Orthogonal Partial Least Squares Discriminant Analysis(OPLS-DA)and univariate statistical analysis identified six differential compounds.Among which 2-AP was mainly derived from direct transfer from AL,while other changes were associated with alterations in amino acid,organic acid,and lipid metabolism during fermentation.Aroma recombination experiments further confirmed that 2-AP,2-phenylethanol,3-methylbutanol,1-octen-3-ol,and dihydro-5-pentyl-2(3H)-furanone were key contributors to the overall aroma profile of AL FRC.These findings demonstrate that AL addition effectively enhances the aroma quality of FRC,laying the groundwork for subsequent research into AL's potential to improve the flavor of grain products.
基金funded by the National Natural Science Foundation of China(No.32302266).
文摘Bitter gourd(fruit of Momordica charantia L.)is a popular vegetable and medical herb known for its intense bitter taste.However,its major bitter-tasting compounds have not been fully characterized.This study aimed to decode its bitterness by application of the sensomics approach.Combining solvent extraction,sensory analysis-guided fractionation and purification with medium-pressure liquid chromatography and high-pressure liquid chromatography,nine bitter-tasting cucurbitane-type triterpenoids were isolated from bitter gourd.The structures of isolated compounds were determined by high-resolution mass spectrometry and nuclear magnetic resonance spectroscopy.The bitter taste recognition thresholds of isolated compounds were in the range from 1.4 mg/L((23E)-3β-O-malonyl-7β,25-dihydroxycucurbita-5,23-dien-19-al,9)to 19.1 mg/L(yeojooside C,5)in 3%ethanol as determined by trained human assessors.Quantification with UPLC-MS/MS demonstrated their natural concentrations in bitter gourd fruits were in the range between 14.2±0.9 mg/kg(yeojooside C,5)and 245.6±22.1 mg/kg(3-O-malonylmomordicine I,10)on a dry weight basis.Calculation of the dose-over-threshold(DoT)factors showed three compounds,namely 3-O-malonylmomordicine I(10),momordicine I(3),and(23E)-3β-Omalonyl-7β,25-dihydroxycucurbita-5,23-dien-19-al(9)were the bitter principles in bitter gourd fruits.On the other hand,momordicoside K(2),which had been known as a bitter principle of bitter gourd for more than forty years,had been proven to be an extraction and isolation artifact rather than a natural component of the plant.Besides,an acid-catalyzed isomerization reaction in the side chain of cucurbitane was discovered,which might explain the formation mechanism of many cucurbitane-type triterpenoids from bitter gourd.
基金supported by Henan University of Tech-nology High-level Talent Research Fund(2025BS089).
文摘The aroma compounds of semi-sweet white wines(WWs)with different alcohol by volume(WW1 and WW2:8.5%vol;WW3 and WW4:11.5%vol)were compared.A total of 80 aroma compounds were identified by comprehensive two-dimensional gas chromatography-time-of-flight mass spectrometry-olfactometry(GC×GC-TOFMS-O).Among these,esters(n=34),terpenes(n=18),and alcohols(n=14)constituted the predominant aroma compounds.Ester contents were significantly higher in the WW1 and WW2(8.5%vol),whereas terpenes and alcohols were more abundant in the WW3 and WW4(11.5%vol).Additionally,ethyl 3-methylbutanoate,ethyl octanoate,and ethyl 3-hydroxybutanoate exhibited higher flavor dilution factors(>243).Based on headspace gas chromatography-ion mobility spectrometry(HS-GC-IMS),the methyl hexanoate and isoamyl acetate as characteristic markers for 8.5%vol WWs,while linalool andβ-pinene for 11.5%vol WWs.The tropical fruity,honey,floral,and citrus-like aromas were dominant in 8.5%vol WW,while citrus,wine,and spice-like aromas were dominant in 11.5%vol WWs.Esters impart fruity and floral aromas,while terpenes are primarily responsible for citrus notes based on sensomics.Based on flavoromics analysis,a total of 19 differential aroma compounds with variable importance in projection(VIP)higher than 1.This study elucidated the relationship between alcohol by volume and aroma profile by employing integrated multi-omics methodologies,thereby providing valuable guidance for the processing of semi-sweet WW.
