Coffee Bean Characterization Using Terahertz Sensing

Coffee bean sorting is currently based primarily on visual appearance and near-infrared techniques that probe the bean’s skin. However, sorting based on compositional differences has significant potential to optimize the roasting process. We present a novel coffee bean sorting method using terahertz...

Full description

Saved in:
Bibliographic Details
Main Authors: Dook van Mechelen, Daan Meulendijks, Milan Koumans
Format: Article
Language:English
Published: MDPI AG 2025-03-01
Series:Sensors
Subjects:
Online Access:https://www.mdpi.com/1424-8220/25/7/2096
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1849769461764063232
author Dook van Mechelen
Daan Meulendijks
Milan Koumans
author_facet Dook van Mechelen
Daan Meulendijks
Milan Koumans
author_sort Dook van Mechelen
collection DOAJ
description Coffee bean sorting is currently based primarily on visual appearance and near-infrared techniques that probe the bean’s skin. However, sorting based on compositional differences has significant potential to optimize the roasting process. We present a novel coffee bean sorting method using terahertz (THz) spectroscopy, which effectively penetrates both green and roasted beans. Our findings show that the optical properties of coffee beans at THz frequencies are primarily governed by internal moisture levels. To demonstrate industrial feasibility, we implement a robot-guided THz sensing system capable of scanning beds of beans for automated sorting. More broadly, our results confirm the potential of THz technology for moisture content analysis across various applications.
format Article
id doaj-art-e37b4eafc1314c95b6f023ecd5ff491f
institution DOAJ
issn 1424-8220
language English
publishDate 2025-03-01
publisher MDPI AG
record_format Article
series Sensors
spelling doaj-art-e37b4eafc1314c95b6f023ecd5ff491f2025-08-20T03:03:24ZengMDPI AGSensors1424-82202025-03-01257209610.3390/s25072096Coffee Bean Characterization Using Terahertz SensingDook van Mechelen0Daan Meulendijks1Milan Koumans2Department of Electrical Engineering, Eindhoven University of Technology, 5600 MB Eindhoven, The NetherlandsDepartment of Electrical Engineering, Eindhoven University of Technology, 5600 MB Eindhoven, The NetherlandsDepartment of Electrical Engineering, Eindhoven University of Technology, 5600 MB Eindhoven, The NetherlandsCoffee bean sorting is currently based primarily on visual appearance and near-infrared techniques that probe the bean’s skin. However, sorting based on compositional differences has significant potential to optimize the roasting process. We present a novel coffee bean sorting method using terahertz (THz) spectroscopy, which effectively penetrates both green and roasted beans. Our findings show that the optical properties of coffee beans at THz frequencies are primarily governed by internal moisture levels. To demonstrate industrial feasibility, we implement a robot-guided THz sensing system capable of scanning beds of beans for automated sorting. More broadly, our results confirm the potential of THz technology for moisture content analysis across various applications.https://www.mdpi.com/1424-8220/25/7/2096optical properties of coffee beansmoisture level of coffee beanscoffee bean sortingTHz spectroscopy
spellingShingle Dook van Mechelen
Daan Meulendijks
Milan Koumans
Coffee Bean Characterization Using Terahertz Sensing
Sensors
optical properties of coffee beans
moisture level of coffee beans
coffee bean sorting
THz spectroscopy
title Coffee Bean Characterization Using Terahertz Sensing
title_full Coffee Bean Characterization Using Terahertz Sensing
title_fullStr Coffee Bean Characterization Using Terahertz Sensing
title_full_unstemmed Coffee Bean Characterization Using Terahertz Sensing
title_short Coffee Bean Characterization Using Terahertz Sensing
title_sort coffee bean characterization using terahertz sensing
topic optical properties of coffee beans
moisture level of coffee beans
coffee bean sorting
THz spectroscopy
url https://www.mdpi.com/1424-8220/25/7/2096
work_keys_str_mv AT dookvanmechelen coffeebeancharacterizationusingterahertzsensing
AT daanmeulendijks coffeebeancharacterizationusingterahertzsensing
AT milankoumans coffeebeancharacterizationusingterahertzsensing