The essential oil content in caraway species (Carum carvi L.)

Abstract

Studies were conducted to determine the effect of different extraction methods (steam distillation and supercritical fluid extraction (SFE)) on caraway (C. carvi cultivars Rekord, Prochan and Kepron) seeds, the effect of harvest time on the amount of essential oil, and to compare the various mill types (ETA 0067 with millstones, splintery mill VIPO and cryogenic mill Vibrom 2). Seeds were harvested before maturation and in full ripeness. Roundup [glyphosate] was used as a ripening modifier, and Alert [4-bromo-2-(4-chlorophenyl)-1-(ethoxymethyl)-5-(trifluoromethyl)-1H- pyrrole-3-carbonitrile] and Prelude 10 [prochloraz] as fungicides. The alternative SFE method determined the essential oils in small samples. Upon steam distillation, the essential oil amounts (in weight percent) in whole and ground caraway seeds were 2 (RSD=1.05%) and 2.6 (RSD=1.25%), respectively; upon SFE, the essential oil amounts in whole and ground seeds were 0.09 (RSD=1.56%) and 2.55 (RSD=2.00%), respectively. In whole caraway extracts, the carvone content was 81.53%; in ground caraway extracts, the carvone content declined to 66.37%. The best recovery was achieved in the splintery mill VIPO, 2.55 weight % with RSD=2.00%, in the ETA mill, 1.79 weight % with RSD=1.36%, and cryogenic mill, 1.72 weight % with RSD=1.50%. Samples collected before maturation had lower essential oil content than samples harvested in full ripeness. Samples collected before harvest had elongated, narrow seeds, while those gathered after ripeness had rounder seeds. Roundup increased the essential oil content. Likewise, the fungicides significantly increased the essential oil content, with Alert recording the highest improvement. No significant differences were observed between the cultivars, and the interaction and treatment of the cultivars did not show any significant differences.