Study of odor from boiled eggs over time using gas chromatography

In this study, emission characteristics of volatile odorant species released from boiled egg samples were investigated and correlated to boiled egg aging and growth of microorganisms. To this end, air samples from boiled eggs were collected at five different times during storage at (elapsed (E-) days of 0, 1, 3, 6, and 9). The concentrations of the volatile organic compounds (VOC) and reduced sulfur compounds (RSC) were measured by thermal desorber (TD)/gas chromatography (GC)/mass spectrometry (MS) and TD/GC/pulsed flame photometric detector (PFPD), respectively. The emission patterns of volatile components generally fell into three distinct stages: (1) fresh: E-0 and 1, (2) decaying or intermediate: E-3, and (3) decayed: E-6 and 9. In terms of the magnitude of concentration (ppb) and odor activity value (OAV), H2S at the fresh stage (E-0) was the most critical component of odor with 3655 and 8915, respectively. The overall results of this study, if examined in terms of the sum of OAV for all odorants during the whole period, suggest that the strongest odorant emission occurs from the fresh boiled eggs with its value exceeding that of others by about an order of magnitude.