Recovery of Bioactive Constituents from Olive Leaf Pruning Waste of Five Different Cultivars: A Comparison of Green Extraction Techniques to Maximize Health Benefits

Olive leaves, once discarded as pruning waste, hide a treasure trove of health-boosting compounds—but the way we extract them changes everything.

The olive oil industry faces a mounting challenge: tons of pruning waste, mostly leaves, end up as environmental burden. But what if these leaves could become a goldmine of bioactives? A new study dives into this potential, comparing two green extraction strategies on leaves from five cultivars—'Caiazzana', 'Carolea', 'Itrana', 'Leccino', and 'Frantoio'.

One method used sequential ultrasound-assisted maceration (UAM) with n-hexane and ethanol, while the other employed compressed fluids: supercritical fluid extraction (SFE) followed by pressurized liquid extraction (PLE). The results were striking. UAM with ethanol excelled at pulling out polyphenols (like luteolin derivatives) and triterpenes (notably maslinic acid), while PLE yielded the highest secoiridoids, such as secologanoside.

When tested for antioxidant power, PLE extracts won, likely due to their richer mix of flavonoids, secoiridoids, and HCA derivatives. Meanwhile, SFE extracts, rich in fatty acids and triterpenes, showed moderate antioxidant activity but outstanding AChE inhibition—a key target for neurological health. This study underscores a simple truth: the extraction method determines the treasure you unlock, turning waste into a sustainable source of wellness.

Key Points

• Green extraction methods compared on five olive cultivars' pruning waste.
• PLE extracts show best antiradical activity; UAM-EtOH targets polyphenols.
• SFE extracts excel in AChE inhibition, hinting at neuroprotective potential.