Chemical characterisation of old cabbage (Brassica oleracea L. var. acephala) seed oil by liquid chromatography and different spectroscopic detection systems

Abstract

We report an extensive chemical characterisation of fatty acids, triacylglycerols, tocopherols, carotenoids and polyphenols contained in the oil extracted from old cabbage (Brassica oleracea L. var. acephala) by cold-pressing of the seeds. Analyses were performed by GC-FID combined with mass spectrometry, HPLC with photodiode array, fluorescence and mass spectrometry detection. The 94% of the total fatty acids were unsaturated, rappresented by erucic acid (more than 50%) followed by linoleic, linolenic and oleic acids accounting for approximately 10% each. The most abundant triacylglycerols (>13%) were represented by erucic–gadolenic–linoleic, erucic–eruci–linoleic and erucic–erucic–oleic. Among tocopherols, γ-tocopherol accounted for over 70% of the total content. Thirteen carotenoids and 11 polyphenols were identified and measured. In particular, the total content in carotenoids was 10.9 ppm and all-E-lutein was the main component (7.7 ppm); among polyphenols, six hydroxycinnamic acids and five flavonoids, were identified by combining information from retention times, PDA and MS data.

Keywords:

• Brassica oleracea
• fatty acids
• triacylglycerols
• carotenoids
• tocopherols
• polyphenols
• HPLC-PDA-ESI-MS

Acknowledgements

The authors gratefully acknowledge Shimadzu and Sigma-Aldrich/Supelco Corporations for their continuous support.

Disclosure statement

No potential conflict of interest was reported by the authors.