Tuning of Proanthocyanidin Extract's Composition through Quaternary Eutectic Solvents Extraction

Area of Science:

• Green Chemistry
• Natural Product Extraction
• Biomass Valorization

Background:

• Current proanthocyanidin extraction methods face limitations in specificity and yield, hindering industrial use.
• Sustainable sourcing and novel extraction techniques are crucial for wider application.
• Eutectic solvents offer a promising alternative due to their low cost, ease of preparation, and tunable properties.

Purpose of the Study:

• To explore the effective extraction of proanthocyanidins from grape pomace using a quaternary eutectic solvent.
• To investigate the ability to tune proanthocyanidin characteristics, including mean degree of polymerization and galloylation percentage.
• To optimize extraction yield and compare it with conventional methods.

Main Methods:

• Utilized a quaternary eutectic solvent composed of choline chloride, glycerol, ethanol, and water.
• Varied the composition of the eutectic solvent to influence extract characteristics.
• Investigated the effect of temperature on extraction yield, up to 100 °C.

Main Results:

• Achieved tunable mean degree of polymerization (6.0–7.37) and galloylation percentage (32.5%–47.1%).
• Maintained high extraction yields (above 72.2 mg/g biomass).
• Increased extraction yield by 238% at 100 °C compared to conventional methods.

Conclusions:

• Eutectic solvents provide an effective and tunable method for proanthocyanidin extraction from grape pomace.
• This approach offers a sustainable and industrially viable alternative for producing high-quality proanthocyanidins.
• Optimized temperature significantly enhances extraction efficiency, demonstrating the method's potential.