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Environmental Compensation for Robust Tea Aroma Classification Based on an Electronic Nose and Machine Learning

*Budi Sumanto orcid scopus  -  Department of Electrical Engineering and Informatics, Vocational College, Universitas Gadjah Mada, Yogyakarta, Indonesia
Ummi Kaltsum orcid scopus  -  Department of Physics Education, Faculty of Mathematics, Natural Sciences, and Information Technology Education, Universitas Persatuan Guru Republik Indonesia Semarang, Indonesia
Galih Setyawan orcid scopus  -  Department of Electrical Engineering and Informatics, Vocational College, Universitas Gadjah Mada, Yogyakarta., Indonesia
Ganjar Alfian orcid scopus  -  Department of Electrical Engineering and Informatics, Vocational College, Universitas Gadjah Mada, Yogyakarta., Indonesia
Dzulkifli Daeng Syauqi  -  Department of Electrical Engineering and Informatics, Vocational College, Universitas Gadjah Mada, Yogyakarta., Indonesia
Ariesta Martiningtyas Handayani orcid scopus  -  Department of Electrical Engineering and Informatics, Vocational College, Universitas Gadjah Mada, Yogyakarta., Indonesia
Kombo Othman Kombo orcid  -  Department of Natural Sciences, College of Science and Technical Education, Mbeya University of Science and Technology, Mbeya., Tanzania, United Republic of
Received: 20 Jul 2026; Revised: 25 Aug 2026; Accepted: 26 Aug 2026; Available online: 31 Aug 2026; Published: 31 Aug 2026.

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Abstract

Classifying tea aromas using an electronic nose (e-nose) system offers rapid, non-destructive quality assessment. However, metal oxide semiconductor (MOS)-based gas sensors are often affected by temperature and humidity, reducing classifier robustness. To address this, we propose an environmental compensation approach to boost robustness in machine learning-based tea aroma classification. Specifically, we analyzed 400 tea samples (100 per class: black, green, red, yellow) using an e-nose with 10 MOS sensors under three scenarios: (A) sensor features only, (B) integration of temperature–humidity features, and (C) temperature–humidity-based signal compensation before feature extraction. For classification, we used SVM, Random Forest, KNN, and a soft voting ensemble. Notably, Scenario C performed best, achieving 85.00% accuracy with SVM. Furthermore, robustness analysis revealed that KNN led on test data (RI=0.9851), while SVM was perfect in cross-validation (RI=1.000). These results confirm that environmental compensation effectively improves the MOS e-nose system stability.

Keywords: Electronic nose; MOS sensor; Tea aroma classification; Environmental compensation; machine learning

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Section: Articles
Language : EN
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