###### Abstract  
To investigate the key odor-active compounds in children's soy sauce (CSS), volatile components were extracted by means of solvent extraction coupled with solvent-assisted flavor evaporation (SE-SAFE) and solid-phase microextraction (SPME). Using gas chromatography-olfactometry (GC-O) and gas chromatography-mass spectrometry (GC-MS), we identified a total of 55 odor-active compounds in six CSSs by comparing the odor characteristics, MS data, and retention indices with those of authentic compounds. Applying aroma extract dilution analysis (AEDA), we measured flavor dilution (FD) factors in SE-SAFE isolates, ranging from 1 to 4096, and in SPME isolates, ranging from 1 to 800. Twenty-eight odorants with higher FD factors and GC-MS responses were quantitated using the internal standard curve method. According to their quantitated results and thresholds in water, their odor activity values (OAVs) were calculated. On the basis of the OAV results, 27 odorants with OAVs \(\geq 1\) were determined as key odorants in six CSSs. These had previously been reported as key odorants in general soy sauce (GSS), so it was concluded that the key odorants in CSS are the same as those in CSS.  
children soy sauce; gas chromatography-olfactometry; AEDA; FD factor; quantitative measurements; OAV; key odorants +
Footnote †: journal: _foods_  
0000-0002-0001-9999-2276][PERSON]  
0000-0002-0002-3390][PERSON]  
0000-0002-0002-3390][PERSON]  
0000-0002-3390-3390-3390-3390-3390-3390-3390-3390-3390-3390-3390-390-3390-3390-390-3390-390-3390-3390-390-3390-  
extracted via solid phase microextraction (SPME) and solvent extraction, and the extracts were analyzed using GC-O. Eleven odor-active compounds were identified, and methional, 3-methylbutanoic acid, guaiacol, 2,5-dimethyl-4-hydroxy-3(2H)furanone (DMHF) and 2-ethyl-4-hydroxy -5-methyl-3(2H)furanone (HEMF) were found to have higher flavor dilution (FD) factors [3]. The key aroma compounds in Japanese SS were characterized using molecular sensory science approaches for the first time in 2007. Twenty-eight aromato-active compounds were identified by means of GC-O analysis in an isolate obtained from Japanese SS through solvent extraction combined with solvent-assisted flavor evaporation (SE-SAFE), and 13 compounds with odor activity values (OAVs) > 1 were determined to be the key odorants [4]. To clarify the compounds' contributions to the odor profiles of Japanese SS, researchers from Japan have investigated the aroma compounds in SS by means of GC-O, and more than 60 aroma-active compounds have been identified. Among those odorants, some compounds, including guaiacol, 4-ethyl guaiacol, 2(and 3)-methylbutanal, methional, DMHF, HEMF, etc., have a higher detection frequency in the analyzed samples [5; 6; 7]. Odor components in Chinese SS have also been examined by means of GC-O, and more than 50 aroma-active compounds have been determined. Some substances, such as 2-phenylethanol, 3-methylbutanol, 3-methylbutanoic acid, 2(and 3)-methylbutanal, methional, benzeneacetaldehyde, HEMF and dimethyl trisulfide, have been identified as aroma-active compounds in all Chinese SS samples [8; 9]. The odorants in five Chinese high-salt liquid-state soy sauces were investigated using modified gas chromatography-mass spectrometry-olfactometry. A total of 195 odor-active compounds were detected, and methional, maltol, guaiacol, 4-ethylguaiacol, 2-acetylpyrrole, 2-acetylfuran, 2-phenylethanol, furfural and DMHF showed high FD factors [10].  
Because of the lack of reports about the odor-active compounds and key odorants in CSS, the aims of the present study were (i) to screen and identify the aroma-active compounds in CSS using GC-O, (ii) to quantitate the odorants identified, (iii) to identify the key odorants contributing to the characteristic odor of CSS by calculating the odor activity values (OAV, the ratio of an odorant concentration to its odor threshold) of those odor-active substances, and (iv) to determine if there are difference between CSS and GSS in key odorants.