Organic Acids in Soy Source

Organic acids in soy source were analyzed using RSpak KC-811. Generally, comparing the two types of soy source, full body type and light body type, the latter has smaller content of organic acids, especially, the contant of lactic acid is small. Another type of soy source which is produced by chemical method and not by fermentation method is characterized by its large content of leuvlinic acids.


Sample : Soy sauce
1. Phosphoric acid, etc.
2. Citric acid
3. Pyruvic acid
4. Malic acid
5. Succinic acid
6. Lactic acid
7. Formic acid
8. Acetic acid
9. Levulinic acid
10. Pyroglutamic acid

Columns      : Shodex RSpak KC-LG (8.0mmID*50mm) + KC-811 (8.0mmID*300mm) x 2
Eluent       : 4.8mM HClO4 aq.
Reagent      : 10-fold diluted ST3-R (for post-column method)
Flow rate    : (Eluent); 1.0mL/min, (Reagent) ; 1.1mL/min 
Detector     : VIS(430nm)
Column temp. : 50deg-C