Variation in oil content, fatty acid and phytosterols profile of Onopordum acanthium L. during seed development

Abstract

This study has determined oil, fatty acid (FA) and phytosterols content during the ripening of the Tunisian Onopordum acanthium L. seeds. In total, nine FAs and six phytosterols were identified. The main FAs were linoleic acid (0.18–8.06 mg/g of seed) followed by oleic acid (0.051–2.45 mg/g of seed), palmitic acid and stearic acid. Pentadecanoic acid was detected, for the first time, in unripe fruits and the two last stages of development were characterised by a relative abundance of erucic acid. Overall, β-sitosterol (34.5–77.79% of total sterols) was the major 4-desmethylsterols during maturation. The first episodes of growth were characterised by the best amounts of stigmasterol and campesterol, while stigmastanol and Δ7 sitosterol had quoted the semi-ripe and fully ripe fruits; however, cholesterol was absent. These findings are useful in understanding a potential new source of important natural compounds (Phytosterols and USFA) found in this fruit and when harvest should be undertaken to optimise desired FA and phytosterols content.

Keywords::

• Onopordum acanthium seeds
• fatty acid composition
• lipid content
• β-sitosterol
• MUFA
• n − 6 PUFA
• stages of maturity

Acknowledgements

The authors gratefully acknowledge Dr Sharon Curtis for her technical advices; Justin Renaud and Abderrahman Hashem for their reading and corrections. A large part of this work was carried out in the laboratory of mass spectrometry in the university of Ottawa, Ontario, Canada.

Additional information

Funding

The authors thank the Tunisian ministry of higher education and scientific research for financially supporting this investigation.