Alternative Assisted Extraction Methods of Phenolic Compounds Using NaDESs

Area of Science:

• Green Analytical Chemistry
• Sustainable Solvents
• Phytochemical Extraction

Background:

• The industry is shifting towards eco-friendly principles, prioritizing less harmful solvents for manufacturing.
• Green analytical chemistry (GAC) promotes the use of green solvents, with deep eutectic solvents (DESs) and natural deep eutectic solvents (NaDESs) emerging as highly promising.
• These solvents exhibit unique features and broad applications, particularly in extracting small bioactive compounds.

Purpose of the Study:

• To review novel 'solvent-free' extraction techniques, focusing on microwave-assisted extraction (MAE) and ultrasound-assisted extraction (UAE).
• To evaluate the potential of DESs and NaDESs as effective solvents for extracting phenolic compounds (PCs) from various olive oil-related matrices.
• To assess the nature, efficacy, and selectivity of DESs/NaDESs in extracting specific bioactive phytochemicals.

Main Methods:

• Review of recent advancements in 'solvent-free' extraction techniques, including MAE and UAE.
• Analysis of DESs and NaDESs for extracting phenolic compounds from virgin olive pomace, leaves, twigs, virgin/extra virgin olive oil, olive cake, and olive mill wastewaters.
• Examination of experimental designs and process optimization studies for promising DESs/NaDESs.

Main Results:

• DESs and NaDESs demonstrate significant potential as effective and selective solvents for phenolic compounds.
• MAE and UAE, in conjunction with DESs/NaDESs, offer efficient methods for extracting bioactive compounds like secoiridoids, lignans, phenolic acids, and alcohols.
• The reviewed literature supports the viability of DESs/NaDESs as sustainable alternatives to petrochemicals.

Conclusions:

• DESs and NaDESs are viable green alternatives to traditional solvents for extracting valuable compounds from olive industry byproducts.
• The combination of these novel solvents with advanced extraction techniques like MAE and UAE enhances efficiency and sustainability.
• These findings support the broader application of DESs/NaDESs in the cosmetic, pharmaceutical, and food industries.