Every Part of the Olive Has Value: Maximum Polyphenol Recovery from Olive Fruit, Leaves, and Pits Using Supercritical CO₂

The olive tree (Olea europaea L.) has held an important place in nutrition and health for thousands of years. Olive oil stands out as the most well-known and valuable product of this tree. However, recent scientific studies reveal that the olive fruit offers a much broader bioactive potential when evaluated not only for its oil but also for its fruit, leaves, and pits.

The olive pomace, pits, and leaves obtained after pruning, which are released during industrial olive oil production, are often considered “waste.” However, these fractions contain much higher concentrations of polyphenols and valuable phenolic compounds, especially oleuropein, compared to olive oil itself.

Published in the journal Current Perspectives on Medicinal and Aromatic Plants (CUPMAP) by the Polat Makina R&D team, this study presents a holistic approach covering all components of the olive, scientifically demonstrating how these by-products can be converted into high value-added raw materials.

Technology: Hybrid Power with PEX1002C (CO₂ + Ethanol)

In this study, olive fruit, primarily sourced from the Aydın region, along with olive leaves and olive pits, were processed using the PEX1002C Supercritical Fluid Extraction (SFE) System developed by Polat Makina.

The distinctive aspect of the research is that it goes beyond the use of pure CO₂ by integrating food-grade ethanol into the process as a co-solvent. This hybrid approach has significantly improved extraction efficiency by increasing the solubility of phenolic compounds.

Research Findings

The data obtained from the process optimized with Polat Makina technology is revolutionary for the food and pharmaceutical industries:

Olive Pulp: The extraction yield, which was 32.11% with pure CO2, increased to 54.21% with the addition of ethanol; the total polyphenol content increased from 527 mg/kg to 1470 mg/kg.

Olive Leaf: The total polyphenol content has increased from 485 mg/kg to 1275 mg/kg.

Olive Pit: The polyphenol content in the extract obtained from pits, which are generally used as fuel, has increased from 354 mg/kg to 1180 mg/kg with the optimized method.

Oleuropein Surge: 3000-Fold Increase: The amount of oleuropein, the most valuable component of olive leaves and known for its powerful antioxidant effect, has shown a very high increase with the ethanol-assisted SFE method. The Oleuropein content, which was 22.75 ng/mL in standard CO2 extraction, reached 68,360.10 ng/mL with the method optimized by Polat Makina. Similarly, significant increases were recorded in other valuable components such as 3-hydroxytyrosol, vanillin, and ferulic acid.

Why This Technology?

1.         Maximum Bioactivity: The study shows that the antioxidant capacity (DPPH test) of the extracts obtained increases approximately 3-fold (5.98 -> 19.72 µmol TE/g) with the use of ethanol.

2.         Sustainability: Olive by-products, which are considered waste, are returned to the economy.

3.         Industrial Scalability: Polat Makina systems offer this sensitive process on an industrial scale with standard quality.

Conclusion

This study demonstrates that all olive fractions, from the fruit to the leaves and pits, can be converted into high value-added raw materials for cosmetics, food supplements, and health-focused products when processed with the right technology.

Furthermore, high-polyphenol olive oils can qualify as functional foods and be positioned in the health-focused product category if they meet the health claim criteria defined by the European Union.