[Spectroscopic methods applied to component determination and species identification for coffee]

Area of Science:

• Food Science
• Analytical Chemistry

Background:

• Coffee quality is influenced by its nutrient composition.
• Understanding the differences between coffee types is crucial for consumers and industry.

Purpose of the Study:

• To determine and compare the nutrient quality of ground, instant, and chicory coffees.
• To identify key chemical markers differentiating coffee varieties.

Main Methods:

• Inductively Coupled Plasma Atomic Emission Spectrometry (ICP-ES) for mineral elements.
• Ultraviolet (UV) spectrometry for caffeine determination.
• Fourier Transform Infrared (FTIR) spectroscopy for organic matter and detection.
• Oxidation-reduction titration for oxalate measurement.

Main Results:

• Instant coffee exhibited 2-3 times higher caffeine and significantly higher oxalate than ground coffee.
• Ground coffee had lower Magnesium (Mg), Phosphorus (P), and Zinc (Zn) but higher Copper (Cu) compared to instant coffee.
• Chicory coffee generally showed lower overall mineral content than instant coffee.
• FTIR spectroscopy effectively differentiated coffee types and detected caffeine and oxalate.

Conclusions:

• Spectroscopic and titration methods provide effective means for coffee quality assessment.
• Significant nutritional differences exist between ground, instant, and chicory coffees.
• FTIR spectroscopy offers a rapid method for coffee authentication and quality control.