Discrimination of Rice Varieties Using Attenuated Total Reflectance-Fourier Transform Infrared (ATR-FTIR) Spectroscopy Combined with Chemometric Methods

¹ Universitas Lancang Kuning, Graduate School of Agricultural Sciences, 28261 Pekanbaru, Indonesia
² Center for Environmental & Sustainable Tropical Agricultural Research, 28261 Pekanbaru, Indonesia
³ National Research and Innovation Agency (BRIN), Research Center for Food Technology and Processing (PRTPP), 55861 Yogyakarta, Indonesia
⁴ Universitas Riau, Department of Chemical Engineering, 28293 Pekanbaru, Indonesia
⁵ Universitas Lancang Kuning, Department of Agricultural Product Technology, 28261 Pekanbaru, Indonesia
⁶ Universitas Lancang Kuning, Department of Agrotechnology, 28261 Pekanbaru, Indonesia
⁷ Tokyo University of Agriculture, Department of International Food and Agricultural Science, 156-8502 Tokyo, Japan

^* Corresponding author: indra.purnama@unilak.ac.id

Abstract

Ensuring the authenticity and quality of rice varieties is crucial for protecting market value and maintaining consumer trust. This study evaluates the potential of Attenuated Total Reflectance-Fourier Transform Infrared (ATR-FTIR) spectroscopy combined with chemometric methods to accurately discriminate three Indonesian rice varieties: Inpari42, Pandan Wangi, and Logawa. Spectral data collected in the mid-infrared region (4000−600 cm⁻¹) were analyzed using Partial Least Squares-Discriminant Analysis (PLS-DA), sparse PLS-DA (sPLS-DA), and Hierarchical Cluster Analysis (HCA). While PLS-DA provided clear varietal separation, minor overlaps were observed, which were effectively resolved by sPLS-DA through the identification of key spectral variables in carbohydrate, protein, and lipid regions. HCA further validated the classification, forming distinct clusters for each variety. This study highlights ATR-FTIR spectroscopy as a rapid, non-destructive, and reliable tool for rice variety discrimination, with promising applications for global rice quality control and authentication.