This study compared the stability of odor compounds in three different types of polymer sampling bags. Tedlar, PET (polyethylene terephthalate) and aluminized polyester bag were used. A sample was collected from the interior of a new automobile which was parked in an outdoor parking lot. It was found that the Tedlar bag showed lower stability for odor active compounds than the PET bag. Meanwhile, the PET bag had good stability for odor compounds compared to the aluminized polyester bag. The PET bag showed a stability for the molecules smaller than toluene that was comparable to the canister, but showed a lower recovery for molecules bigger than C7. The FID signal of the sample in the PET bag was reduced by 1.7times after 3days storage compared to 24 h storage. The number of detected odor active compounds was reduced by half, and odor intensity was also decreased by 2~3 degrees. Considering the factors of repeated use, usability and price, a PET bag covered with a black plastic bag was the most appropriate approach for odor sampling in an automobile interior.

In this study fuji apples variation were measured during gradual decay, stored 5 weeks at 25℃. A aluminum and glass emission chamber were used for visual inspection throughout the experiment. The sampling was performed by using polyester aluminum bags and Tenax-TA tubes. In addition, GC/FID/O and TD-GC/MS were used for monitoring the compound of odor and its density variation during each storing period. By visual inspection, we found that the apples started decaying in 4th week and were rotten to core in 5th week. In contrast, individual odor analysis shows that the apples flavor reduced gradually and dramatically increased with the odor of old apples and apple cider in 3rd week, which was before visual identification of decay. This phenomenon was due to ongoing internal decay. ethyl 2-methylbutanoate, ethyl propanoate and 2-methylbutyl acetate were the major factor of this off-flavor in this period (3rd week). After visible observation of decay (4th week and 5th week), ethyl acetate, ethyl butanoate and hexyl ethanoate were emitted, which smells bitter or sour. Above 6 odors are closely related with apples decay, and measurement of smell or density of these odors could easily check the apples status. We expect measuring composition variation can be applied for food storage and management cause of not only internal change checking but also monitoring pre-decay phenomenon.

In this study, odor active compounds, emitted from food waste composting facility, were analyzed and their contribution degree were evaluated. Sample gases were collected at the inlet and outlet of scrubbing tower and bio-filter, respectively. The odor active compounds were separated by GC/FID/Olfactometry (GC/FID/O) and identified by GC/MS. Odor intensity and SNIF (Surface of Nasal Impact frequency) were used to evaluate contribution of each odor active compound. It was possible to calculate contribution rate (%) and reduction rate (%) of odor active compounds using analysis and evaluation of contribution degree of odor active compounds. As a result, the compounds showing the high contribution degree were fatty acids, ketones at inlet and aldehydes, ketones at outlet. Deodoring equipment of food waste composting facility appeared effective for the reduction of aldehydes, ketones but appeared week for the reduction of aldehydes. Although scrubbing tower and bio-filter could reduce 7 times of odor level, the outlet gases had odor dillution ratio of 3000, which exceed the allowable levels of Korean guideline by 6 times.