Exploring Spent Coffee Grounds: Comprehensive Morphological Analysis and Chemical Characterization for Potential Uses

Area of Science:

• Agricultural Science
• Biomass Valorization
• Waste Management

Background:

• Agroindustry generates significant byproducts, with spent coffee grounds (SCGs) being a major waste stream from coffee production.
• SCGs possess a complex lignocellulosic structure, presenting opportunities for valorization.
• Effective waste management and resource sustainability are critical in the agro-industrial sector.

Purpose of the Study:

• To comprehensively analyze the chemical composition and physical properties of spent coffee grounds (SCGs).
• To explore the potential applications of SCGs in both food and non-food sectors.
• To assess the safety of SCGs for potential human consumption and their utility as a soil amendment.

Main Methods:

• Chemical analysis for cellulose, hemicellulose, and lignin content.
• Morphological characterization using Field Emission Scanning Electron Microscopy (FESEM).
• Spectroscopic (ATR-FTIR, XRD) and thermal (TGA) analyses.
• Mineral content assessment via ICP-AES and AAS.

Main Results:

• SCGs comprise 30.2% cellulose, 25% hemicellulose, and 12% lignin, with an amorphous structure (low crystallinity).
• ATR-FTIR and TGA confirmed the presence of polysaccharides, oils, and typical plant cell wall components.
• Mineral concentrations are within safe daily intake limits, indicating suitability for consumption and soil amendment.

Conclusions:

• Spent coffee grounds (SCGs) are a valuable lignocellulosic biomass resource.
• SCGs can be utilized in composite materials and as an organic soil amendment after fermentation.
• This research supports waste valorization and promotes resource sustainability in the agro-industry.