Short Lecture "A green process for the complete valorisation of Olea europaea leaves, based on limonene extraction, enrichment, and recycling"

Olive leaves, the main CO₂ generating side-product of olive tree cultivation, are rich in bioactives, such as the secoiridoid oleuropein, the precursor of the bioactive oleocanthal present in olive oil [1], and oleanolic and maslinic acids with applications in skin care products [2]. Under the frame of circular economy, a novel and highly efficient fractionation of crude olive leaf extract was designed. Application of ultrasound extraction, supercritical CO₂ extraction and molecular distillation for recycling the green solvent (D- limonene), resulted in the efficient fractionation of olive extract into three enriched fractions ready to be used as active ingredients, and recycling of D-limonene. Target compounds were quantified (HPLC- DAD/polyphenols, HPLC-ELSD/triterpenoids). Each extract was enriched in distinct chemical classes: chlorophylls and pigments; olive polyphenols (22.4% oleuropein); olive triterpenoids (75.3% oleanolic acid, and 16.9% maslinic acid). Oleuropein was further purified using state-of-the-art automated techniques (MPLC/HPLC, green solvents), and was used as a synthon for the green semisynthesis of novel, olive dialdehyde-based bioactive molecules, based on hydrolysis steps with the aid of enzymes in aqueous media. In conclusion, we report for the first time the complete valorisation of the main agricultural side-product of olive cultivation with the use of solely green techniques, for producing diverse active ingredients such as olive polyphenols and secoiridoids, and triterpenic acids.

Funding ERDF, “Synergies of Research and Innovation (ΑΤΤΡ4-0359462)”, ROP of Attica, MIS 5185066.

Publikationsverlauf

Artikel online veröffentlicht:
16. November 2023

• References

• 1 Martins BT. et al. J Agric Food Chem 2022; 70: 14109-28
• 2 Jing Z. et al. Curr Drug Targets 2021; 22: 1496-506