In this study,the changes of flavor profile,the succession rules of active microorganisms and their correlation were analyzed during the fermentation process of industrial Sichuan radish paocai,in order to further exp...In this study,the changes of flavor profile,the succession rules of active microorganisms and their correlation were analyzed during the fermentation process of industrial Sichuan radish paocai,in order to further explore the composition of ingredients that constitute the unique flavor characteristics of industrial Sichuan radish paocai,and the microorganisms and enzymes that may contribution to it.To this end,molecular sensory,high performance liquid chromatography and metatranscriptomics were employed to identify the aroma-active compounds,non-volatile compounds and active microorganisms during the 197-day fermentation process of industrial Sichuan radish paocai,respectively.Twenty aroma-active compounds were identified,of which 12 compounds had odor activity values≥1,and some off-flavor compounds were significantly lower than those of fresh radish.After 100 days of fermentation,aroma-active compounds began to accumulate extensively with the dominant active microorganisms transforming from fungi to bacteria.Among the potential formation pathways of 14 aroma-active compounds,most of which were dominated by Lactobacillus and Debaryomyces,and were contributed by other microorganisms mainly belong to Lactobacillales,Saccharomycetales and Bacillales.This study provides new insights into the flavor formation and microbial metabolic roles of industrialized paocai,as well as valuable references for screening and isolation of functional strains,expression and characterization of flavor enzymes.展开更多
The aim of this study was to investigate the seasonal alterations in microbial composition and quality parameters of Paocai brine during back-slopping fermentation. With relatively constant reducing sugar levels acros...The aim of this study was to investigate the seasonal alterations in microbial composition and quality parameters of Paocai brine during back-slopping fermentation. With relatively constant reducing sugar levels across seasons, higher titratable acidity and lower pH was observed in summer and autumn. Organic compound analysis revealed higher production of lactic acid, acetic acid and γ-aminobutyric acid (GABA), and less free amino acids in summer. As for bacterial composition, Lactobacillus gradually flourished across winter, spring, summer and autumn, accompanied by decline of Pediococcus abundance. For fungal composition, Kazachstania and Pichia were dominant genera, with Pichia flourishing in spring and summer. Pearson's correlation analysis illustrated that, through driving microbial succession, jar temperature was the primary factor influencing quality of Paocai brine during back-slopping fermentation. Understanding the quality fluctuation of fermented vegetables across seasons along with ambient difference would be helpful for developing targeted technology to obtain products with stable and reproducible quality.展开更多
基金supported by the National Natural Science Foundation of China(Program No.31871788).
文摘In this study,the changes of flavor profile,the succession rules of active microorganisms and their correlation were analyzed during the fermentation process of industrial Sichuan radish paocai,in order to further explore the composition of ingredients that constitute the unique flavor characteristics of industrial Sichuan radish paocai,and the microorganisms and enzymes that may contribution to it.To this end,molecular sensory,high performance liquid chromatography and metatranscriptomics were employed to identify the aroma-active compounds,non-volatile compounds and active microorganisms during the 197-day fermentation process of industrial Sichuan radish paocai,respectively.Twenty aroma-active compounds were identified,of which 12 compounds had odor activity values≥1,and some off-flavor compounds were significantly lower than those of fresh radish.After 100 days of fermentation,aroma-active compounds began to accumulate extensively with the dominant active microorganisms transforming from fungi to bacteria.Among the potential formation pathways of 14 aroma-active compounds,most of which were dominated by Lactobacillus and Debaryomyces,and were contributed by other microorganisms mainly belong to Lactobacillales,Saccharomycetales and Bacillales.This study provides new insights into the flavor formation and microbial metabolic roles of industrialized paocai,as well as valuable references for screening and isolation of functional strains,expression and characterization of flavor enzymes.
基金financially supported by National Natural Science Foundation of China(NSFC 32001668)Funding for“1+9”Leading Key Scientific and technological Research Tasks of Sichuan Academy of Agricultural Sciences(1+9KJGG007)+4 种基金Sichuan Science and Technology Program(2022YFN0014)Funding for Top-notch Talent of Sichuan Academy of Agricultural Sciences,Funding for Innovative Leading Youth Talents of Sichuan Academy of Agricultural Sciences,Funding for Youth of Sichuan Academy of Agricultural Sciences,Science and Technology Program of Sichuan Province(2019YJ0598)Natural Science Foundation of Sichuan Province(2022NSFSC1648)Research and Industrialization on Key Common Processing Technologies of Yunnan Special Fermented vegetables(202002AE320006)Innovation and Entrepreneurship Seedling Project of Science and Technology Program of Sichuan Province(2021JDRC0133,2021085).
文摘The aim of this study was to investigate the seasonal alterations in microbial composition and quality parameters of Paocai brine during back-slopping fermentation. With relatively constant reducing sugar levels across seasons, higher titratable acidity and lower pH was observed in summer and autumn. Organic compound analysis revealed higher production of lactic acid, acetic acid and γ-aminobutyric acid (GABA), and less free amino acids in summer. As for bacterial composition, Lactobacillus gradually flourished across winter, spring, summer and autumn, accompanied by decline of Pediococcus abundance. For fungal composition, Kazachstania and Pichia were dominant genera, with Pichia flourishing in spring and summer. Pearson's correlation analysis illustrated that, through driving microbial succession, jar temperature was the primary factor influencing quality of Paocai brine during back-slopping fermentation. Understanding the quality fluctuation of fermented vegetables across seasons along with ambient difference would be helpful for developing targeted technology to obtain products with stable and reproducible quality.
