Arginine,an abundant amino acid in kimchi,is metabolized by lactic acid bacteria(LAB)with arginine deiminase(ADI)genes,producing ammonia and thereby increasing nitrate and nitrite levels.Therefore,fermentation strateg...Arginine,an abundant amino acid in kimchi,is metabolized by lactic acid bacteria(LAB)with arginine deiminase(ADI)genes,producing ammonia and thereby increasing nitrate and nitrite levels.Therefore,fermentation strategies aimed at reducing arginine catabolism are needed.Unlike other LAB,Leuconostoc mesenteroides lacks ADI genes.To examine the impact of fermenting kimchi with an L.mesenteroides starter culture,we compared naturally fermented kimchi(kimchi A)and starter-fermented kimchi(kimchi B).In kimchi A,diverse LAB species were detected,whereas kimchi B mainly included L.mesenteroides.LC-MS/MS and multivariate analyses identified key metabolic differences.Orthogonal partial least squares-discriminant analysis(OPLS-DA)revealed a clear separation between kimchi A and B.Notably,malic acid,citric acid,and arginine showed significant differences,with high variable importance in projection(VIP)scores;these are essential in malolactic acid fermentation.Correlation analyses demonstrated strong links between L.mesenteroides and these metabolic changes.L.mesenteroides lacks genes for malic and citric acid catabolism,confirming its role in preventing malolactic acid fermentation and nitrogen cycling and supporting its value for enhancing kimchi safety and taste.展开更多
Garlic plays a significant role in kimchi fermentation,serving as a key flavor component,a source of microbial nutrients,and a natural antimicrobial agent.This study aimed to elucidate garlic’s specific contribution ...Garlic plays a significant role in kimchi fermentation,serving as a key flavor component,a source of microbial nutrients,and a natural antimicrobial agent.This study aimed to elucidate garlic’s specific contribution to kimchi fermentation,focusing on its effects as a fermentation enhancer,nutritional substrate,and microbial regulator,particularly on the starter culture Leuconostoc mesenteroides.Kimchi samples were prepared with varying garlic concentrations(1%,2%,and 4%).Metagenomic and metabolite profiling was performed using 16 S rRNA gene sequencing,and metabolite profiling was conducted using liquid chromatography-mass spectrometry.Linear discriminant analysis effect size revealed that garlic-supplemented kimchi exhibited a distinct microbial profile,dominated by Weissella kandleri,Leuconostoc gelidum,and Lactiplantibacillus plantarum.Besides,an antibacterial activity assay demonstrated garlic’s inhibitory effect on lactic acid bacteria(LAB)such as W.confusa,L.carnosum,L.plantarum,Latilactobacillus sakei,and L.mesenteroides.Multivariate analysis of metabolites confirmed significant metabolic shifts,notably difference levels of hydroxyisocaproic acid(HICA),mannitol,glucose,sucrose,and lactic acid-key indicators of fermentation progress and microbial activity.HICA,mannitol and lactic acid are products of LAB activity,and glucose and sucrose levels indicate carbohydrate utilization during fermentation.Our results revealed that garlic concentration,rather than acidity,was the dominant factor influencing L.mesenteroides growth during the early stages of fermentation,highlighting the critical role of ingredient composition in microbial succession.These findings highlight the dual role of garlic as a selective antimicrobial agent,shaping bacterial community structure,while simultaneously modulating metabolite profiles during kimchi fermentation.展开更多
Starter cultures can enhance sensory properties during the starter kimchi fermentation.However,while many studies have primarily focused on physicochemical properties,the impact of starters on flavor perception re-mai...Starter cultures can enhance sensory properties during the starter kimchi fermentation.However,while many studies have primarily focused on physicochemical properties,the impact of starters on flavor perception re-mains unclear.The aim of this study was to assess the impact of starter culture inoculation,specifically Com-panilactobacillus allii WiKim39 and Lactococcus lactis WiKim0124,on aroma and flavor perception through a comparison of metabolite profiling and electronic tongue and nose data.Notably,19 and 11 compounds were identified using UHPLC-Q-Orbitrap-MS and HPLC,respectively.Principal component analysis revealed that variations in fermentation metabolites and sensory properties were significantly categorized based on the particular starter culture employed during the ripening process.Moreover,the correlation analysis between the 19 key fermentative metabolites and e-tongue measurements in each starter kimchi revealed significant differ-ences in sourness(AHS),bitterness(SCS),and comprehensive taste(CPS and PKS)sensors.The e-nose system identified four major volatile compounds contributing to the sweetness and off-flavor-related aroma profile of the starter kimchi.These findings highlight the significant impact that starter culture has on taste and flavor development,serving as a valuable guide in predicting sensory properties during starter kimchi fermentation.展开更多
基金support from a grant[KE 2501-1]provided by the World Institute of Kimchi,which is funded by the Ministry of Science and ICT,Republic of Korea.
文摘Arginine,an abundant amino acid in kimchi,is metabolized by lactic acid bacteria(LAB)with arginine deiminase(ADI)genes,producing ammonia and thereby increasing nitrate and nitrite levels.Therefore,fermentation strategies aimed at reducing arginine catabolism are needed.Unlike other LAB,Leuconostoc mesenteroides lacks ADI genes.To examine the impact of fermenting kimchi with an L.mesenteroides starter culture,we compared naturally fermented kimchi(kimchi A)and starter-fermented kimchi(kimchi B).In kimchi A,diverse LAB species were detected,whereas kimchi B mainly included L.mesenteroides.LC-MS/MS and multivariate analyses identified key metabolic differences.Orthogonal partial least squares-discriminant analysis(OPLS-DA)revealed a clear separation between kimchi A and B.Notably,malic acid,citric acid,and arginine showed significant differences,with high variable importance in projection(VIP)scores;these are essential in malolactic acid fermentation.Correlation analyses demonstrated strong links between L.mesenteroides and these metabolic changes.L.mesenteroides lacks genes for malic and citric acid catabolism,confirming its role in preventing malolactic acid fermentation and nitrogen cycling and supporting its value for enhancing kimchi safety and taste.
基金support from a grant[KE 2501-1]provided by the World Institute of Kimchi,which is funded by the Ministry of Science and ICT,Republic of Korea.
文摘Garlic plays a significant role in kimchi fermentation,serving as a key flavor component,a source of microbial nutrients,and a natural antimicrobial agent.This study aimed to elucidate garlic’s specific contribution to kimchi fermentation,focusing on its effects as a fermentation enhancer,nutritional substrate,and microbial regulator,particularly on the starter culture Leuconostoc mesenteroides.Kimchi samples were prepared with varying garlic concentrations(1%,2%,and 4%).Metagenomic and metabolite profiling was performed using 16 S rRNA gene sequencing,and metabolite profiling was conducted using liquid chromatography-mass spectrometry.Linear discriminant analysis effect size revealed that garlic-supplemented kimchi exhibited a distinct microbial profile,dominated by Weissella kandleri,Leuconostoc gelidum,and Lactiplantibacillus plantarum.Besides,an antibacterial activity assay demonstrated garlic’s inhibitory effect on lactic acid bacteria(LAB)such as W.confusa,L.carnosum,L.plantarum,Latilactobacillus sakei,and L.mesenteroides.Multivariate analysis of metabolites confirmed significant metabolic shifts,notably difference levels of hydroxyisocaproic acid(HICA),mannitol,glucose,sucrose,and lactic acid-key indicators of fermentation progress and microbial activity.HICA,mannitol and lactic acid are products of LAB activity,and glucose and sucrose levels indicate carbohydrate utilization during fermentation.Our results revealed that garlic concentration,rather than acidity,was the dominant factor influencing L.mesenteroides growth during the early stages of fermentation,highlighting the critical role of ingredient composition in microbial succession.These findings highlight the dual role of garlic as a selective antimicrobial agent,shaping bacterial community structure,while simultaneously modulating metabolite profiles during kimchi fermentation.
基金supported by the World Institute of Kimchi[grant number KE2401-1].
文摘Starter cultures can enhance sensory properties during the starter kimchi fermentation.However,while many studies have primarily focused on physicochemical properties,the impact of starters on flavor perception re-mains unclear.The aim of this study was to assess the impact of starter culture inoculation,specifically Com-panilactobacillus allii WiKim39 and Lactococcus lactis WiKim0124,on aroma and flavor perception through a comparison of metabolite profiling and electronic tongue and nose data.Notably,19 and 11 compounds were identified using UHPLC-Q-Orbitrap-MS and HPLC,respectively.Principal component analysis revealed that variations in fermentation metabolites and sensory properties were significantly categorized based on the particular starter culture employed during the ripening process.Moreover,the correlation analysis between the 19 key fermentative metabolites and e-tongue measurements in each starter kimchi revealed significant differ-ences in sourness(AHS),bitterness(SCS),and comprehensive taste(CPS and PKS)sensors.The e-nose system identified four major volatile compounds contributing to the sweetness and off-flavor-related aroma profile of the starter kimchi.These findings highlight the significant impact that starter culture has on taste and flavor development,serving as a valuable guide in predicting sensory properties during starter kimchi fermentation.
