Environmental and Yield Comparison of Quick Extraction Methods for Caffeine and Chlorogenic Acid from Spent Coffee...

Area of Science:

• Green Chemistry
• Biomass Valorization
• Separation Science

Background:

• Spent coffee grounds (SCG) are a rich source of valuable compounds like chlorogenic acid (CA) and caffeine (Caf).
• Efficient extraction methods are needed to valorize SCG and recover these bioactive compounds.
• Current extraction techniques vary in efficiency and environmental impact.

Purpose of the Study:

• To compare the efficacy of three distinct laboratory-scale extraction methods for CA and Caf from SCG.
• To evaluate the environmental impact of different extraction solvents and processes.
• To identify optimal extraction strategies for industrial-scale recovery of bioactive compounds from SCG.

Main Methods:

• Extraction of CA and Caf from SCG using three methods: supramolecular solvent, water with vortex, and water assisted by ultrasound.
• All extractions were conducted for a 1-minute duration at room temperature.
• Life Cycle Assessment (LCA) was employed to compare the environmental footprint of water and supra-solvent extraction methods for commercial product manufacturing.

Main Results:

• Water extraction assisted by ultrasound yielded the highest amounts of CA (1.15 mg/g) and Caf (0.972 mg/g).
• Supra-solvent extraction resulted in lower CA recovery due to solvent phase affinity.
• Environmental assessment indicated that solvent type and extraction yield significantly influence overall environmental impact.

Conclusions:

• Ultrasound-assisted water extraction is a highly efficient and promising method for recovering CA and Caf from SCG.
• The choice of solvent and extraction efficiency are critical factors for the environmental sustainability of SCG valorization.
• Findings provide valuable insights for industries seeking to scale up the extraction of these valuable compounds from coffee waste.