Co-fermention Of Ginkgo Rice Wine By Non-Saccharomyces Yeast And Saccharomyces Cerevisiae Based On Metabonomics

In recent years,with the rapid development of China's economy and the improvement of people's living standards,people pay more and more attention to the nutrition and health of their own diet.Wine with unique flavor and certain health functions is more and more popular among consumers.In this paper,based on the study of the kinetics of saccharomyces cerevisiae and non-saccharomyces cerevisiae isolated and identified in the laboratory,saccharomyces cerevisiae with the best fermentation performance and non saccharomyces cerevisiae with the best aroma producing ability were selected;the technological parameters of the liquid co-fermentation of non-saccharomyces cerevisiae and saccharomyces cerevisiae to prepare ginkgo rice wine were optimized by using ginkgo which is one of the food and drug homology instead of part of rice as raw materials;the process parameters were optimized by using analytical chemistry instrument combined with intelligent sensory technology,the types,contents and aroma characteristics of flavor substances in the fermentation process of ginkgo rice wine were identified,and the micro differences of typical aroma and flavor substances were obtained;Metabonomics technology was used to analyze the microbial metabolites in the fermentation process of Ginkgo rice wine,and the metabolic pathway of differential metabolism was constructed.The main results are as follows:1.The growth and fermentation performance of three saccharomyces cerevisiae strains and four non-saccharomyces cerevisiae strains isolated and identified from several Chinese local sweet koji were compared by GC-MS analysis and sensory evaluation SITCL254(Saccharomyces cerevisiae)has strong fermentation ability,fast hypoglycemic rate and strong alcohol content;SITCY125(Wickerhamomyces anomalus)has rapid proliferation,more suitable for the brewing environment of rice wine,excellent fermentation ability and strong ability to produce phenylethanol,isobutanol and hexanol.2.The mixed culture of two yeast strains under liquid condition was studied.The results showed that:in mixed culture,SITCL254 could inhibit the ester production of SITCY125,but the alcohol content of rice wine was significantly higher than that of single strain fermentation of SITCY125;when the inoculation ratio of SITCY125 and SITCL254 was 100:1,the ester production reached 3.213 g/L.The yield of mercaptan decreased,the yield of alcohol,ester and terpene increased,and the mellow flavor of rice wine was better than that of simultaneous inoculation fermentation.3.The results showed that the optimum technological parameters for the production of ginkgo rice wine were as follows:45%ginkgo saccharification liquid and 55%glutinous rice saccharification liquid were mixed,5×10~6 cfu/m L Wickerhamomyces anomalus was inoculated first,fermented for 24 h at 29?,and then inoculated with 5×10~4 cfu/m L Saccharomyces cerevisiae for 36 h.During the fermentation of ginkgo rice wine,the content of soluble solids decreased sharply(24.00°Brix?5.05°Brix),and the alcohol content increased gradually(0?6.14%vol).The contents of total phenols,flavones and ginkgolide B were 10087?g GAE/ml,0.058 mg Rutin/ml and 6.92 mg/L,respectively.After fermentation for 60 h,the total phenol content was 12070?g GAE/m L,the flavone content was 0.026 mg Rutin/m L,and the ginkgolide B content was less than 7.63 mg/L.Compared with before fermentation,the total reducing capacity and DPPH free radical scavenging rate of ginkgo rice wine increased after fermentation.Ginkgolic acid,4-hydroxysilver acid,ferulic acid,hydroferulic acid and folic acid were the main phenolic substances of unfermented ginkgo;ginkgolic acid,4-hydroxysilver acid,ferulic acid,quinic acid,shikimic acid,erucic acid,maleic acid,sorbic acid,succinic acid,folic acid and isoflavones were the main phenolic substances in ginkgo rice wine fermented by SITCL254 and SITCY125.4.The results showed that the bands overlapped seriously in the infrared absorption spectrum,there were many characteristic absorption peaks,and there were obvious intensity differences.A total of 76 volatile aroma components were detected by HS-SPME-GC/MS,including 17 alcohols,11 esters,14 aldehydes,3 ketones,6 phenols,10 acids and 15 others.With the fermentation process,the kinds and contents of esters increased significantly,the contents of alcohols increased first and then decreased,and the contents of esters and acids decreased gradually.GC-IMS was used to detect the typical volatile aroma components in the fermentation process of ginkgo rice wine.A total of 29 volatile aroma components were identified,including esters,alcohols,ketones and aldehydes.The contents of esters such as ethyl octanoate,ethyl hexanoate,ethyl butyrate,isoamyl acetate,propyl acetate,isobutyl acetate,ethyl propionate and ethyl acetate were higher at 24-48 h of fermentation,while the contents of alcohols and ketones such as 2-pentanone,acetone,1-butanol,1-hexanol and 1-propanol were higher at 60 h of fermentation.PCA analysis showed that the flavor of ginkgo rice wine varied greatly at different fermentation time,especially at 60 h.Heracles II gas chromatography electronic nose was used to detect the changes of aroma during the fermentation process of ginkgo rice wine.It was found that the difference of radar spectrum was large,indicating that the difference of odor was obvious.The discriminant index of PCA analysis showed that the overall odor information of 24 h and 48 h fermentation was the closest,and it was also close to 36 h fermentation of ginkgo rice wine;the odor information of non fermentation and 60 h fermentation of ginkgo rice wine was significantly different.Ts-5000z electronic tongue was used to detect the taste changes of ginkgo rice wine during fermentation.It was found that the bitterness and bitter aftertaste of ginkgo rice wine decreased significantly with the progress of fermentation,and the taste and fresh aftertaste also showed a downward trend.The comprehensive quality of ginkgo rice wine after fermentation for 60 h was the best.5.During the fermentation of ginkgo rice wine,bitter substances such as xanthine,delicious substances such as IMP and L-glutamic acid and sour substances such as malic acid and citric acid changed significantly.Xanthine,adenine and alanine are potential markers in the fermentation process of ginkgo rice wine.The above research results can provide reference for the brewing and quality improvement of ginkgo rice wine,and provide reference for promoting the industrialization,standardization and modernization of ginkgo rice wine.The above research results can provide reference for promoting the industrialization,standardization and modernization of ginkgo rice wine.