Optimization of Phenolic-Enriched Extracts from Olive Leaves via Ball Milling-Assisted Extraction Using Response...

Area of Science:

• Agricultural Chemistry
• Natural Product Chemistry
• Process Engineering

Background:

• Olive leaves are a rich source of valuable phenolic compounds with potential health benefits.
• Traditional extraction methods often face challenges in efficiency and scalability.
• Developing advanced extraction techniques is crucial for maximizing the recovery of bioactive compounds from plant materials.

Purpose of the Study:

• To optimize and evaluate ball milling-assisted extraction (BMAE) for phenolic compounds from olive leaves.
• To determine the optimal conditions for extracting oleuropein, luteoloside, and hydroxytyrosol.
• To assess the efficiency and industrial applicability of BMAE for these target compounds.

Main Methods:

• Utilized ball milling-assisted extraction (BMAE) for phenolic compound extraction from olive leaves.
• Employed response surface methodology (RSM) and Box-Behnken design (BBD) to optimize extraction parameters (temperature, solvent-to-solid ratio, milling speed).
• Quantified extracted compounds using ultra-high-performance liquid chromatography-mass spectrometry (UPLC-MS) to determine recovery rates.

Main Results:

• Identified optimal BMAE conditions yielding high recoveries for key phenolic compounds.
• Achieved 79.0% ± 0.9% recovery for oleuropein at 56.4 °C, 39.1 mL/g, and 429 rpm.
• Obtained 74.6% ± 1.2% recovery for luteoloside at 58.4 °C, 31.3 mL/g, and 328 rpm; and 43.1% ± 1.3% for hydroxytyrosol at 51.5 °C, 32.7 mL/g, and 317 rpm.

Conclusions:

• Ball milling-assisted extraction (BMAE) is a highly efficient method for extracting oleuropein, luteoloside, and hydroxytyrosol from olive leaves.
• The high energy of ball milling enhances cell wall disruption, improving mass transfer and compound recovery.
• BMAE demonstrates significant potential for scalable industrial production of valuable olive leaf phenolics.