Changes in the Flavor Compounds in Soy Sauce Stored in Antioxidation Containers

Antioxidation containers, recently used to keep soy sauce fresh, are known to preserve the color of soy sauce. However, it is unclear whether these containers also maintain the flavor of soy sauce. We evaluated the effect of these containers on the flavor compounds of soy sauce using GC/MS with solid-phase microextraction (SPME) and stir bar sorptive extraction (SBSE). The soy sauce was stored for 30 weeks in a PET bottle or two antioxidation containers, a pouch in a dispenser (PID) and a Delami bottle. SMPE-GC/MS analysis revealed that the soy sauce in the PET bottle had an increased amount of pyrazines and short-chain fatty acids and a decreased amount of esters compared with the antioxidation container samples. 2,3,5-Trimethylpyrazine was slightly increased in the Delami bottle sample than the PID sample, and a similar tendency was observed for the color change of soy sauce. Dimethyl trisulfide and nonanal were analyzed by SBSE-GC/MS to improve the stability of analytes compared with SPME. Dimethyl trisulfide and nonanal were the most significantly increased flavor compounds of soy sauce, and the increase of these compounds was reduced in the antioxidation containers.