Abstract
To clarify the re-odorization mechanism, the refined rape seed oil was oxidized with dried air.
The volatile carbonyl compounds were caught in a trap of 2, 4-dinitrophenylhydrazine solution, while the non-volatiles in the oil were extracted with Girard reagent to convert into 2, 4-DNPH compounds.
These compounds were then passed through alumina column with benzen to collect only monocarbonyl compounds. Saturated and unsaturated mono-carbonyl compounds were determined by applying paper chromatography and ultra-violet absorption spectrum analysis with the following results :
1) C4 and C6 aldehydes covered over 70% of the volatile carbonyl compounds and over one half of the C8 and C10 components was consisted of unsaturated compounds.
2) The non-volatile carbonyl compounds contained more saturated ones compared with the volatiles.
