By the addition of rice wine koji, enhancement of the reactivity was observed for the baker＇s yeast reduction of β-keto esters into （S）-β-hydroxy esters with high enantiomeric purity （73-98%）.
In this study, effect of rice added to meju dough was evaluated based on the variation of nutritional ingredients and bacterial community diversity in finished doenjang. The ratio of rice added to meju dough (cooked a...In this study, effect of rice added to meju dough was evaluated based on the variation of nutritional ingredients and bacterial community diversity in finished doenjang. The ratio of rice added to meju dough (cooked and crushed soybean before fermentation) was 0, 0.2, and 0.4 based on dry weight. Free amino acids, minerals, polyphenol, and total phenolic compounds relatively decreased by addition of rice. However, 2,2-diphenyl-1-picrylhydrazyl free radical (DPPH) scavenging and ferric ion reduction activity was not influenced. Organic acids, which are fermentation metabolites, significantly increased in proportion to percentage balance of rice. Seven and four volatile compounds (VCs) were detected in doenjang prepared without and with rice, respectively, and contents of VCs were significantly lower in the rice-supplemented doenjang. Bacterial community diversity was significantly increased by addition of rice to meju dough. Rice alters chemical composition, fermentation products, and bacterial diversity, but does not downgrade the nature of doenjang.展开更多
The effect of thermally processed rice koji extracts on survival of yeast Saccharomyces cerevisiae was examined in comparison with non-heated koji extract. In chronological life span (CLS) tests on high-sugar fermenta...The effect of thermally processed rice koji extracts on survival of yeast Saccharomyces cerevisiae was examined in comparison with non-heated koji extract. In chronological life span (CLS) tests on high-sugar fermentation, the survivals of the yeast cells grown with heated koji extracts were higher than non-heated koji extract. Heat treatment of the extracts by autoclaving led to a loss in most of amino acids due to the Maillard reaction, although histidine contents slightly increased. In glucose-arginine mixtures, arginine was partly converted to histidine by autoclaving and the addition of histidine prolonged the CLS of yeast cells. The yeast cells grown with the non-heated extracts were more resistant to oxidative stress whereas the antioxidant activities were lower than those of the heated extracts. The yeast cells grown with the heated extracts were more tolerant to ethanol and had a higher reduction capacity in the late stationary phase when the cells were incubated in the presence of ethanol. Maillard reaction products elevated the levels of reactive oxygen species to yeast cells grown under ethanol stress in the late stationary phase. These results suggest that thermally processed koji extracts can act as a protectant against ethanol stress during the late stationary phase of yeast growth and extend the CLS due to the increase of histidine contents by autoclaving.展开更多
This paper introduces the origin and research status of traditional Yaoqu(Chinese medicinal koji)in China,and advances in the research of preparation and development of pure functional Yaoqu.The study results showed t...This paper introduces the origin and research status of traditional Yaoqu(Chinese medicinal koji)in China,and advances in the research of preparation and development of pure functional Yaoqu.The study results showed that the quality of the products was significantly improved when pure Yaoqu was used as saccharifying agent in the brewing of sake,soy sauce and other products.Based on the high saccharification performance and special functional components,Yaoqu can be applied to the development of fermented food.展开更多
Koji making is a crucial stage of soy sauce production that affects the later fermentation efficiency and final product quality.However,little is understood about the dynamics and roles of microbiota throughout the ko...Koji making is a crucial stage of soy sauce production that affects the later fermentation efficiency and final product quality.However,little is understood about the dynamics and roles of microbiota throughout the koji making,especially the functional microbes responsible for flavor formation.In this work,high-throughput sequencing revealed that the top 3 bacteria were Weissella,Staphylococcus,and Bacillus,and the top 2 fungi were Aspergillus and Trichosporon.The fermentation process could divide into 2 stages based on microbiota succession:0 h and12-44 h.Additionally,6 organic acids,15 amino acids,and 30 volatile flavors were detected,of them,1-octen-3-ol and 3-octanone were the two characteristic volatile flavors of koji.Analysis of the corre-lation between microbiota,physicochemical properties,and flavors indicated that Weissella,Staphylococcus,Bacillus,and Trichosporon were the key microorganisms responsible for promoting environmental development and the formation of flavors.What’s more,Staphylococcus,Leuconostoc,and Pichia were identified strongly positively correlated with 1-octen-3-ol and 3-octanone,which probably play pivotal roles in the unique aroma formation of koji.These findings provide insight into the potential for developing profitable starter cultures for the manufacture of high-quality soy sauce products.展开更多
Influences of salt(5%-20%w/w of digested material)and soybean koji(3%-10%w/w of digested material)on chemical properties of fish sauce from tilapia frame after 4 months’fermentation using response surface methodology...Influences of salt(5%-20%w/w of digested material)and soybean koji(3%-10%w/w of digested material)on chemical properties of fish sauce from tilapia frame after 4 months’fermentation using response surface methodology was studied.Results found that the salt content showed quadratic effect on ammonia nitrogen and amino nitrogen while linear effect on formaldehyde nitrogen and NaCl contents of samples were observed(P<0.05).Estimation response surfaces revealed that the formaldehyde nitrogen,ammonia nitrogen and amino nitrogen contents decreased while NaCl content increased as salt content increased.For the effect of koji,the significant effect of koji content on non-enzymatic browning value of fish sauce samples in linear manner was observed(P<0.05).The non-enzymatic browning value of sample increased as koji content increased.The both of salt and koji contents showed the linear effect on total acidity value while two-factor interaction terms on total nitrogen of sample was found(P<0.05).For the consumer acceptability testing,an acceptance score of the incubated fish sauce sample with a values of 6.50-7.43(like slightly to like moderately)was obtained.The results showed that it is possible to make a good quality fish sauce from tilapia frame by-product.展开更多
文摘By the addition of rice wine koji, enhancement of the reactivity was observed for the baker＇s yeast reduction of β-keto esters into （S）-β-hydroxy esters with high enantiomeric purity （73-98%）.
文摘In this study, effect of rice added to meju dough was evaluated based on the variation of nutritional ingredients and bacterial community diversity in finished doenjang. The ratio of rice added to meju dough (cooked and crushed soybean before fermentation) was 0, 0.2, and 0.4 based on dry weight. Free amino acids, minerals, polyphenol, and total phenolic compounds relatively decreased by addition of rice. However, 2,2-diphenyl-1-picrylhydrazyl free radical (DPPH) scavenging and ferric ion reduction activity was not influenced. Organic acids, which are fermentation metabolites, significantly increased in proportion to percentage balance of rice. Seven and four volatile compounds (VCs) were detected in doenjang prepared without and with rice, respectively, and contents of VCs were significantly lower in the rice-supplemented doenjang. Bacterial community diversity was significantly increased by addition of rice to meju dough. Rice alters chemical composition, fermentation products, and bacterial diversity, but does not downgrade the nature of doenjang.
文摘The effect of thermally processed rice koji extracts on survival of yeast Saccharomyces cerevisiae was examined in comparison with non-heated koji extract. In chronological life span (CLS) tests on high-sugar fermentation, the survivals of the yeast cells grown with heated koji extracts were higher than non-heated koji extract. Heat treatment of the extracts by autoclaving led to a loss in most of amino acids due to the Maillard reaction, although histidine contents slightly increased. In glucose-arginine mixtures, arginine was partly converted to histidine by autoclaving and the addition of histidine prolonged the CLS of yeast cells. The yeast cells grown with the non-heated extracts were more resistant to oxidative stress whereas the antioxidant activities were lower than those of the heated extracts. The yeast cells grown with the heated extracts were more tolerant to ethanol and had a higher reduction capacity in the late stationary phase when the cells were incubated in the presence of ethanol. Maillard reaction products elevated the levels of reactive oxygen species to yeast cells grown under ethanol stress in the late stationary phase. These results suggest that thermally processed koji extracts can act as a protectant against ethanol stress during the late stationary phase of yeast growth and extend the CLS due to the increase of histidine contents by autoclaving.
基金Supported by International Cooperation Project of National Key Research Program"Research on Expression Regulation of Key Genes of Characteristic Microorganisms in Chinese and Japanese Koji and Quality Improvement of Chinese Distiller s Yeast" (2018YFE0127400)Open Project of National New Antibiotic Culture Collection and Management Center of Chengdu University"Analysis of Physical and Chemical Characteristics of Liquor Koji and Screening of Functional Microorganisms" (CCSIIA202202).
文摘This paper introduces the origin and research status of traditional Yaoqu(Chinese medicinal koji)in China,and advances in the research of preparation and development of pure functional Yaoqu.The study results showed that the quality of the products was significantly improved when pure Yaoqu was used as saccharifying agent in the brewing of sake,soy sauce and other products.Based on the high saccharification performance and special functional components,Yaoqu can be applied to the development of fermented food.
基金supported by National Natural Science Foundation of China(Project No.32160547)Basic and Applied Basic Research Foundation of Guangdong Province(Project No.2021B1515120042)+1 种基金Vegetable Industry Technology System Post Expert Project of Jiangxi Province(Project No.JXARS-06)Nanchang University High Value Patent Cultivation Program.
文摘Koji making is a crucial stage of soy sauce production that affects the later fermentation efficiency and final product quality.However,little is understood about the dynamics and roles of microbiota throughout the koji making,especially the functional microbes responsible for flavor formation.In this work,high-throughput sequencing revealed that the top 3 bacteria were Weissella,Staphylococcus,and Bacillus,and the top 2 fungi were Aspergillus and Trichosporon.The fermentation process could divide into 2 stages based on microbiota succession:0 h and12-44 h.Additionally,6 organic acids,15 amino acids,and 30 volatile flavors were detected,of them,1-octen-3-ol and 3-octanone were the two characteristic volatile flavors of koji.Analysis of the corre-lation between microbiota,physicochemical properties,and flavors indicated that Weissella,Staphylococcus,Bacillus,and Trichosporon were the key microorganisms responsible for promoting environmental development and the formation of flavors.What’s more,Staphylococcus,Leuconostoc,and Pichia were identified strongly positively correlated with 1-octen-3-ol and 3-octanone,which probably play pivotal roles in the unique aroma formation of koji.These findings provide insight into the potential for developing profitable starter cultures for the manufacture of high-quality soy sauce products.
文摘Influences of salt(5%-20%w/w of digested material)and soybean koji(3%-10%w/w of digested material)on chemical properties of fish sauce from tilapia frame after 4 months’fermentation using response surface methodology was studied.Results found that the salt content showed quadratic effect on ammonia nitrogen and amino nitrogen while linear effect on formaldehyde nitrogen and NaCl contents of samples were observed(P<0.05).Estimation response surfaces revealed that the formaldehyde nitrogen,ammonia nitrogen and amino nitrogen contents decreased while NaCl content increased as salt content increased.For the effect of koji,the significant effect of koji content on non-enzymatic browning value of fish sauce samples in linear manner was observed(P<0.05).The non-enzymatic browning value of sample increased as koji content increased.The both of salt and koji contents showed the linear effect on total acidity value while two-factor interaction terms on total nitrogen of sample was found(P<0.05).For the consumer acceptability testing,an acceptance score of the incubated fish sauce sample with a values of 6.50-7.43(like slightly to like moderately)was obtained.The results showed that it is possible to make a good quality fish sauce from tilapia frame by-product.
