Changes in Volatile Flavor Compounds of Powdered Dried Bonito (Katsuobushi) during Storage

Abstract

The changes in the volatile flavor compounds of powdered katsuobushi during storage were studied. The headspace vapor of powdered katsuobushi was adsorbed on activated charcoal and then analyzed by gas chromatography (GC) and combined gas chromatography and mass spectrometry (GC-MS). The aroma concentrate obtained on simultaneous distillation-extraction (SDE) was also analyzed. Methanethiol, dimethyl sulfide/carbon disulfide and 2-butanone in the headspace vapor greatly decreased, and hexanal and 2,3-pentanedione greatly increased on the first day. On the other hand, hexanal, (2E)-hexenal and 2,3-pentanedione in the aroma concentrate greatly increased, the changes in phenols and ethers, in quantity, being relatively small. On headspace vapor analysis, 24 compounds were identified, of which 11 were newly found as aroma substances in katsuobushi.