L:litseifolius with various health benefits,which has been approved as a new food material in China since 2017,can be a promising substrate for kombucha.In this study,kombucha using L.litseifolius(L.Komb)as sole raw m...L:litseifolius with various health benefits,which has been approved as a new food material in China since 2017,can be a promising substrate for kombucha.In this study,kombucha using L.litseifolius(L.Komb)as sole raw material was successfully prepared by inoculating a symbiotic culture of bacteria and yeast(SCOBY).The alterations in flavor compounds and microbial communities,as well as their potential correlations during fermentation were investigated.A total of 113 volatile flavor compounds(VFCs)were identified using headspace-solid phase microextraction-gas chromatography mass spectrometry(HS-SPME-GC-MS).Among them,alcohols and acids accounted for a larger proportion.During fermentation,the contents of ethanol,3-methyl-1-butanol,phenylethyl Alcohol,and acetic acid was 142.73-290.92,108.59-371.74,36.09-184.80,and 255.91-685.82μg/L,respectively.The results of high-throughput sequencing analysis indicated that Komagataeibacter,Gluconobacter,and Ralstonia were the dominant bacterial genera,while Zygosaccharomyces was the predominant fungal genus.The Spearman correlation coefficient demonstrated medium-high correlations(|ρ|>0.6)between VFCs and 13 core microbes.The primary alcohols,acids,and esters in L.Komb exhibited strong associations with specific microorganisms,including Komagataeibacter,Gluconobacter,Ralstonia,Stenotrophomonas,and Starmerella.It contributes to understanding the role of core microorganisms in the overall flavor formation of L.Komb,providing valuable reference for practical flavor promotion of kombucha.展开更多
L.litseifolius,a sweet-leafed primarily distributed in southern China,exhibits potential as a novel substrate for kombucha fermentation.This study developed a two-stage co-fermentation to enhance the flavor of L.litse...L.litseifolius,a sweet-leafed primarily distributed in southern China,exhibits potential as a novel substrate for kombucha fermentation.This study developed a two-stage co-fermentation to enhance the flavor of L.litseifolius kombucha,by using Lactobacillus plantarum,Acetobacter pasteurianus,and Kluyveromyces marxianus as co-starters.Co-fermentation significantly altered free amino acids(FAAs),volatile flavor compounds(VFCs),and organic acids(OAs),attenuating the pungent acetic acid odor and imparting a distinctive floral,fruity,and fatty aroma.High-throughput sequencing analysis revealed that Acetobacter pasteurianus maintained dominance throughout the fermentation.Correlation analysis and redundancy analysis(RDA)definitively confirmed the synergistic effects of bacteria and fungi on shaping the final flavor profile,particularly contributing to the formation of floral-fruity aroma,umami,and sourness.Furthermore,untargeted metabolomics identified 40 differential metabolites in triple-strain co-fermentation,including cis-4-coumaric acid,2-isopropylmalic acid,caffeic acid et al.KEGG pathway enrichment analysis mapped probable biosynthetic pathways for these compounds,particularly those involving FAAs(e.g.,alanine,aspartate)and OAs(e.g.,coumarate,succinate).This study provides insights into flavor formation mechanisms in L.litseifolius co-fermentation,offering a scientific basis for developing novel plant-based fermented beverages.展开更多
基金supported by the Science and Technology SMES Innovation Ability Improvement Project of Shandong Province(Project No.2023TSGC0980)the Key Research and Development Program of Changzhou(Project No.CE20222005).
文摘L:litseifolius with various health benefits,which has been approved as a new food material in China since 2017,can be a promising substrate for kombucha.In this study,kombucha using L.litseifolius(L.Komb)as sole raw material was successfully prepared by inoculating a symbiotic culture of bacteria and yeast(SCOBY).The alterations in flavor compounds and microbial communities,as well as their potential correlations during fermentation were investigated.A total of 113 volatile flavor compounds(VFCs)were identified using headspace-solid phase microextraction-gas chromatography mass spectrometry(HS-SPME-GC-MS).Among them,alcohols and acids accounted for a larger proportion.During fermentation,the contents of ethanol,3-methyl-1-butanol,phenylethyl Alcohol,and acetic acid was 142.73-290.92,108.59-371.74,36.09-184.80,and 255.91-685.82μg/L,respectively.The results of high-throughput sequencing analysis indicated that Komagataeibacter,Gluconobacter,and Ralstonia were the dominant bacterial genera,while Zygosaccharomyces was the predominant fungal genus.The Spearman correlation coefficient demonstrated medium-high correlations(|ρ|>0.6)between VFCs and 13 core microbes.The primary alcohols,acids,and esters in L.Komb exhibited strong associations with specific microorganisms,including Komagataeibacter,Gluconobacter,Ralstonia,Stenotrophomonas,and Starmerella.It contributes to understanding the role of core microorganisms in the overall flavor formation of L.Komb,providing valuable reference for practical flavor promotion of kombucha.
基金supported by the Science and Technology SMES Innovation Ability Improvement Project of Shandong Province(Project No.2023TSGC0980)the Key Research and Development Program of Changzhou(Project No.CE20222005).
文摘L.litseifolius,a sweet-leafed primarily distributed in southern China,exhibits potential as a novel substrate for kombucha fermentation.This study developed a two-stage co-fermentation to enhance the flavor of L.litseifolius kombucha,by using Lactobacillus plantarum,Acetobacter pasteurianus,and Kluyveromyces marxianus as co-starters.Co-fermentation significantly altered free amino acids(FAAs),volatile flavor compounds(VFCs),and organic acids(OAs),attenuating the pungent acetic acid odor and imparting a distinctive floral,fruity,and fatty aroma.High-throughput sequencing analysis revealed that Acetobacter pasteurianus maintained dominance throughout the fermentation.Correlation analysis and redundancy analysis(RDA)definitively confirmed the synergistic effects of bacteria and fungi on shaping the final flavor profile,particularly contributing to the formation of floral-fruity aroma,umami,and sourness.Furthermore,untargeted metabolomics identified 40 differential metabolites in triple-strain co-fermentation,including cis-4-coumaric acid,2-isopropylmalic acid,caffeic acid et al.KEGG pathway enrichment analysis mapped probable biosynthetic pathways for these compounds,particularly those involving FAAs(e.g.,alanine,aspartate)and OAs(e.g.,coumarate,succinate).This study provides insights into flavor formation mechanisms in L.litseifolius co-fermentation,offering a scientific basis for developing novel plant-based fermented beverages.
