Extraction and purification of grape seed polysaccharides using pH-switchable deep eutectic solvents-based...

Area of Science:

• Green Chemistry
• Biopolymer Extraction
• Sustainable Separation Technologies

Background:

• T-butanol is a common but environmentally harmful solvent used in three-phase partitioning (TPP).
• Deep eutectic solvents (DESs) offer a recyclable and eco-friendly alternative to traditional organic solvents.
• Grape seed polysaccharides (GSP) are bioactive compounds with potential health benefits.

Purpose of the Study:

• To develop and optimize a DES-based TPP method for efficient extraction and purification of GSP.
• To evaluate the recyclability and regeneration capabilities of the DES system.
• To characterize the extracted GSP.

Main Methods:

• Screening of various DES formulations, with DES-1 (dodecanoic acid: octanoic acid = 1:1) showing optimal performance.
• Single-factor experiments to determine the main influencing factors for GSP extraction.
• Cyclic extraction experiments to assess DES recyclability over 25 cycles.
• Characterization of GSP, including molecular weight and monosaccharide composition.

Main Results:

• The optimized DES-1 based TPP achieved a maximum GSP extraction yield of 98.04 mg/g.
• The DES exhibited excellent recyclability, with minimal loss in extraction yield after 25 cycles.
• Complete recovery of DES extractability was achieved through switching and regeneration.
• The extracted GSP had a molecular weight of 60 kDa and comprised mannose, glucose, galactose, and arabinose.

Conclusions:

• pH-switchable DES provide an efficient, recyclable, and sustainable alternative to t-butanol for GSP extraction.
• The developed method demonstrates the potential for large-scale application in extracting bioactive substances.
• This approach contributes to greener and more sustainable bioprocessing techniques.