Biomolecules extraction from coffee and cocoa by- and co-products using deep eutectic solvents

Area of Science:

• Agro-industrial waste valorization
• Green chemistry and sustainable extraction technologies
• Biomolecular compound isolation

Background:

• Coffee pulp, cocoa husk, and pod husk are abundant agro-residues.
• These residues contain valuable biomolecules like phenolic compounds, fibers, and alkaloids.
• Developing sustainable extraction methods for these biomolecules is crucial.

Purpose of the Study:

• To investigate deep eutectic solvents (DES) as green extraction media for agro-residues.
• To evaluate the extraction capacity of different DES compositions.
• To compare heat stirring-assisted extraction (HSE) and ultrasound-probe assisted extraction (UPAE) for DES-based extraction.

Main Methods:

• Extraction of biomolecules from coffee and cocoa agro-residues using various DES compositions.
• Evaluation of extraction yields using heat stirring-assisted extraction (HSE) and ultrasound-probe assisted extraction (UPAE).
• Identification and quantification of extracted bioactive compounds using UPLC-MS.

Main Results:

• Choline chloride (ChCl)-based DES, particularly lactic acid:ChCl (2:1 mol ratio), demonstrated the highest extraction efficiency.
• Ultrasound-probe assisted extraction (UPAE) was significantly more effective and faster (3 min) than HSE (1 h) for DES-assisted extraction.
• Key bioactive compounds identified include chlorogenic acid, caffeine, and theobromine. Furfural was also produced under specific DES conditions.

Conclusions:

• Deep eutectic solvents offer a sustainable and highly effective method for extracting biomolecules from plant biomass.
• DES-based extraction can simultaneously yield valuable biomolecules and platform chemicals like furfural.
• This approach enhances the valorization of agro-industrial residues, promoting a circular economy.