Yield, Quality and Composition of Cumin Essential Oil as Affected by Storage Period

Essential oils from newly produced (2017) and previous season crop (2016) of cumin (Cuminum cyminum L.) seeds collected from local farmers in Dongla area, north Sudan were extracted and analyzed to determine the effect of storage period on volatile oil yield and quality. The essential oil was extracted using hydro distillation method. Identification of the volatile compounds was performed using gas chromatography-mass spectrometry (GC/MS). Results revealed that oil obtained from cumin (Cuminum cyminum L.) was pale yellow. With respect to oil characteristics, the specific gravity, refractive index, acid value, ester value and other quality characters were not significantly different between the stored and newly harvested seeds. Thirty-eight compounds were separated and identified in cumin seeds essential oil in both seasons with some minor differences in some components between 2016 and 2017 samples. Major effective components of cumin seeds volatile oil were cumin alcohol (4-isopropylbenzyl alcohol), cumin aldehydes as 4-Isopropylbenzaldehyd and 7,7-dimethylbicyclo (4.1.0) hept-3-ene-4-carbaldehyde known as carenal, terpinenes as γ-terpinene and α-terpinene (1,4-Cyclohexadiene, 1-methyl-4-(1-methylethyl) and 1,3-cyclohexadine-1-methanol, 4(1-methethyle)-), β-pinene, o-cymene and p-menthadienol in both stored and newly harvested samples. Differences between the samples season wise were very minor with respect to type of volatile components but percentage oil yield was largely decreased by storage period.