Detection of coffee flavour ageing by solid-phase microextraction/surface acoustic wave sensor array technique...

Area of Science:

• Analytical Chemistry
• Sensor Technology
• Food Science

Background:

• Polymer-coated surface acoustic wave (SAW) sensor arrays show promise for detecting volatile organic compounds (VOCs).
• Accurate monitoring of VOCs is crucial for assessing food quality and shelf-life, such as in coffee storage.

Purpose of the Study:

• To develop a low-cost, highly reproducible sensor setup for detecting VOCs in the parts-per-billion (ppb) range.
• To evaluate the efficacy of a new SAW sensor array for monitoring coffee aging during storage.
• To compare the performance of the SAW sensor array with gas chromatography-flame ionization detection (GC/FID) and sensory analysis.

Main Methods:

• Development of a cost-effective sensor setup utilizing polymer-coated SAW sensor arrays.
• Implementation of a sampling method for reproducible VOC detection.
• Testing the sensor array's performance using coffee aging as a model system.
• Comparative analysis using a standard GC/FID setup and sensory panellists.

Main Results:

• The developed SAW sensor array achieved highly reproducible detection of volatiles in the ppb range.
• GC/FID analysis revealed non-linear concentration characteristics, hindering coffee age prediction.
• The SAW sensor array demonstrated a linear dependency between volatile concentration and coffee storage time, enabling age prediction.

Conclusions:

• The new SAW sensor array system provides a cost-effective and sensitive method for VOC detection.
• This technology offers a linear and reliable approach for monitoring changes in food products like coffee during storage.
• SAW sensor arrays present a viable alternative to traditional methods for objective quality assessment.