An effective method, use of a 2,4-dinitrophenylhydrazine (DNPH) derivatization and high-performance liquid chromatography (HPLC) with ultraviolet (UV) detection, has been used for separation carbonyl compounds. In particular, acetonitrile/water composition as a mobile phase could not separated acrolein/acetone and 2-butanone/ butyraldehyde. In this study, however, that"s compounds separated using acetonitrile/water/tetrahydrofuran as a mobile phase. The resolution was 1.48 and 1.46, respectively. Also, aldehydes and ketones was shown different decrease rate and increase resolution at increase tetrahydrofuran ratio. But butyraldehyde become coeluted methacrolein. Therefore, it is need to consider of mobile phase for separation of butyraldehyde.

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.