Isolation of flavor producing yeast and analysis on aroma characteristics in the natural soy sauce mash

An excellent yeast HT.Y309screened from the natural sauce mash with good flavor,had obvious advantages in aroma,growth rate,salt tolerance,ethanol production capacity,been identified Zygosaccharomyes rouxii by colony and cell morphology analysis,sugar fermentation and other physiological and biochemical characteristics and 18SRNA sequence analysis.To research the aroma characteristics and the contribution to soy sauce flavor of the yeast HT.Y309,Simultaneous Distillation Extraction(SDE) and Gas Chromatography-Mass Spectrometry(GC-MS) were used to compare the volatile flavor compounds in soy sauce with and without HT.Y309fermentation.Results showed that the soy sauce with the yeast HT.Y309fermentation had the main volatile flavor characteristic components of propanol,butanol,isobutanol,isoamyl alcohol,and β-phenylethanol,furfural,benzeneacetaldehyde and other aldehydes,and 4-hydroxy-ethyl-5-methyl-3-furanone(HEMF).