The Study On The Volatile Flavor Characteristics Of Chinese Traditional-type Soy Sauce

Soy sauce is a traditional fermented seasoning with rich flavor that can enhance food flavor and satisfy the people’s pursuit of a better life.It is widely used for food cooking in Asian countries.Chinese traditional-type soy sauce has the unique process of "long-term sun exposure and night dew,turn-over sauce and sun sauce,multi-bacteria participation in fermentation",which gives products a typical flavor characteristic of "strong sauce and rich flavor".Flavor is the key factor determining the quality of soy sauce,which affects the acceptance of consumers.However,at present,there is insufficient research on the volatile compounds and aroma-active compounds of Chinese traditional-type soy sauce with chinese characteristics.Therefore,scientific analysis of its volatile flavor characteristics is of great significance for enriching the unique flavor chemistry theory and quality control of Chinese traditional-type soy sauce.The study took the analysis of volatile flavor characteristics of Chinese traditional-type soy sauce as the target.Based on the analysis of sensory characteristics,the typicality of volatile flavor characteristics of Chinese traditional-type soy sauce and the differences between Japanese soy sauce,Chinese guang-type soy sacue and Chinese traditional-type soy sauce were analyzed from the two aspects of volatile compounds and aroma-active compounds,which could lay the foundation for the understanding of Chinese traditional-type soy sauce flavor chemistry theory and the control of flavor quality.The following was the main contents and conclusions:(1)The study used the scientific sensory description method to characterize the aroma description characteristics of Chinese traditional-type soy sauce.Firstly,the rapid sensory analysis method Napping(?)was used to confirmed the typicality and representativeness of the selected samples.Then,quantitative descriptive analysis(QDA)was used to characterize the aroma descripition characteristics of three types of soy sauce in detail,further principal component analysis(PCA)results showed that the aroma characteristics of caramel-like,nutty and baked of Chinese traditional-type soy sauce were prominent compared with Japanese soy sauce and Chinese guang-type soy sauce.(2)The study used the comprehensive two-dimensional gas chromatography/time-of-flight mass spectrometry(GC×GC-TOFMS)to analyze the volatile compounds in Chinese traditional-type soy sauce.Firstly,head-space solid phase micro extraction(HS-SPME)and solvent-assisted flavor evaporation(SAFE)were used to extract volatile compounds and GC×GC-TOFMS was used to separate and identify volatile compounds.The total of 379 volatile compounds with high reliability were identified in Chinese traditional-type soy sauce,of which 121 were firstly identified in Chinese traditional-type soy sauce.Next,195 volatile compounds with high reliability which had significant differences among Chinese traditional-type soy sauce,Japanese soy sauce and Chinese guang-type soy sauce were identified by HS-SPME-GCxGC×TOFMS combined with multivariate statistical method.Among them,isoeugenol,ethyl 2-methylthioacetate,benzyl methyl sulfide,pantolactone,5.methyl-2-phenyl－2-hexenal,2-propen-1-ol,ethyl 2-hydroxy-3-methylbutyrate,etc.might be potential aroma compounds in soy sauce.(3)The study used gas chromatography-olfactory(GC-O)to analyze the aroma-active compounds that formed the unique sensory style of Chinsese traditional-type soy sauce..The total of 80 aroma-active compounds in Chinsese traditional-type soy sauce were identified by normal phase chromatography combined with GC-O technique.The possible key aroma-active compounds were analyzed,among them,3-methyl-4-pentanolactone,pantolactone,linalool,limonene and bis(2-furfuryl)disulfide were firstly identified as aroma-active compounds in Chinese traditional-type soy sauce.Then,aroma extract dilution analysis(ADEA),multi-method quantitative strategy and odor activity value(OAV)were used to clarify that the key aroma-active compounds which contributed more aroma to Chinese traditional-type soy sauce were sotolone,methional,3-methyl butanal,phenylacetaldehyde,3-methyl butanol,HEMF,HDMF,2-methyl butanal,dimethyl trisulfide and ethyl 2-methyl propionate etc.The differences of the key aroma-active compounds compared with Japanese soy sauce and Chinese guang-type soy sauce included species and concentration,but mainly in concentration.