Metabolites Characters Of Zygosaccharomyces Rouxii Under Osmotic Pressure Of High Glucose Concentration

Zygosaccharomyces rouxii is a type of yeast that can grow in high osmotic pressure,and is often concentrated in apple juice,grape juice,honey and other high-sugar content substances.Although hyperosmotic conditions can prevent the growth and reproduction of some microorganisms.But the highly osmotic ruckellin-binding yeast can still survive.If the number of yeast colonies is too high,it will cause certain quality changes in the concentrated juice and other products.At present,the mechanism of high salt osmotic pressure resistance of Zygosaccharomyces rouxii is studied mainly in the cell membrane,changes in cell wall composition,protein changes,and corresponding gene changes in Zygosaccharomyces rouxii.The mechanism of high glucose osmotic pressure also includes proteomics and transcription.Group changes study etc.In order to explore the differential changes in the metabolism of Z.rouxii under high osmotic pressure,the mechanism of hypertonicity tolerance was interpreted.In this study,the gas chromatography-mass spectrometer was used to determine the difference in extracellular and intracellular metabolites of Z.rouxii under high glucose osmotic pressure and in combination with the PCA model.PLS-DA model selection of differential substances.The selection of different substances was studied during the entire growth period under the hyperosmotic environment of Z.rouxii,and the effect of Z.rouxii on the quality of concentrated apple juice was investigated.The research results of the paper are as follows:(1)The Z.rouxii 1130 was subjected to hyperosmotic and normal conditions and compared with Saccharomyces cerevisiae 2# and extracellularly selected to distinguish between 7-octenoate and 3-(methylthio)propyl.Acetate,2-tridecanol,3-methylbutyl pentadecanoate,ethyl 9-decenoate,3-(methylthio)-1-propanol,2-decanol;The differentially characterized substances glycerol,trehalose,lanosterol,xylitol,and mannitol were selected intracellularly.(2)Not all of the 7 extracellular substances are produced during the entire growth of Z.rouxii.Only 3-(methylthio)-1-propanol occurs during the entire yeast growth period,while7-octenoic acid B The ester appeared only 72 h after the yeast was grown,but it was not detected before 72 h.2-decanol and 3-(methylthio)propyl acetate were only detected at the 72 h time point.9-decenoic acid B The ester was only detected at the 84 h time point;The intracellular glycerol and trehalose were present during the entire yeast growth period,but the content was dynamically changed.Xylitol and ergosterol were only present in the middle and late stages.Mannitol was detected within 0-72 hours and no mannitol was detected at 60 hours.However,sorbitol was detected.Mannitol and sorbitol can be synthesized with each other.In addition,high sugar osmotic pressure suppresses the synthesis of cholesterol,sucrose,and mannose.(3)The Z.rouxii showed logarithmic growth in concentrated fruit juices.There was no significant change in fruit juices 18 days before yeast contamination,but the flavor and aroma components were reduced.However,after 21 days,serious changes have taken place in the flavoring substances,such as alcohol 2-methyl-1-propanol,which has unpleasant odorous substances.