Analysis Of Aroma Compounds Of Soy Sauce Based On GC-MS

In this study, headspace solid-phase microextraction (HS-SPME) and silylation derivatization coupled with gas chromatography-mass spectrometry (GC-MS) was applied to analyze volatile and nonvolatile aroma compounds and identify more rich aroma compounds in soy sauce. At the same time, the contents of the importance compounds were measured. The main contents were as follows:1 Analysis of volatile aroma compounds(1) The saparation effects of HP-5MS and CP-WAX chromatographic columns to the analysis of aroma compounds were investigated, and the performance of HP-5MS was better; The sensitivity and repeatability of the SPME fibers with different polarities were examined, 65?mPDMS/DVB was then selected to extract aroma compounds of soy sauce;By single factor experiment, the optimal extraction conditions were established as follows:the volume of soy sauce sample 8 mL, extraction temperature 60 ? and extraction time 60 min. The method validation show that the degree of precision was well, the linear and veracity for the quantification of the main compounds were also well, and the limits of detection were lower.(2) Under the optimized conditions, a total of 172 volatile aroma compounds were identified, and 13 mutual compounds were determined in ten soy sauce samples.Meanwhile, the contents (156.79?11170.59?g/L) of 40 major compounds, the relative contents of which were more than 1%, were determined. Amomg, ethanol was the mutual major compounds in all samples; Acetic acid, phenyl acetaldehyde, 2-acetylpyrrole,guaiacol, nonanal, 4-guaethol, sorbic acid, 5-methyl-2-phenyl-2-hexylenicaldehyde, and ethyl palmitate were the major compounds in majority samples.2 Analysis of novolatile aroma compounds(1) The affects of derivatization conditions to novolatile aroma analysis of soy sauce were investigated. The results showed the optimal derivatization conditions were: solvent dosage 100?L,derivating agent 125 ?L,derivatization temperature 80 ?,derivatization time 50 min. The method validation show that the degree of precision was well,the linear and veracity for the quantification of amino acids were also well, and the limits of detection were lower.(2) Under the optimized conditions, a total of 96 kinds of novolatile aroma compounds were identified coupled with GC-MS, and 32 mutual compounds were determined in ten soy sauce samples. The main compounds were saccharides, alcohols and other acids. The compounds of dark soy sauces were more than light soy sauces. The relative content of saccharides was superior, and the relative content of other acids was lower in dark soy sauces. The relative contents of amino acids and alcohols were superior, and the relative content of saccharides was lower in in the superfine soy sauces. The numbers of compounds in the superfine soy sauces from different areas were similar, yet the contribution to soy sauce flavor had large difference. Meanwhile, the contents of 13 amino acids were determined. Among, L-isoleucine, L-threonine, glutamic acid, L-lysine and phenylalanine were the mutual amino acids in all samples, and the content was 0.1?1.06g/100mL,0.2 ?1.53g/100mL,0.05 ?2.7g/100mL,0.17?2g/100mL,0.18?2.45 g/100mL, . The others were detected in some samples. The amount of amino acid nitrogen of soy sauce in the study contrasted to grading standard of soy sauce in national standard,and showed the method could conduct a preliminary classification of unknown soy sauce samples.