Combination of light stable isotopic and elemental signatures in Thai Hom Mali rice with chemometric analysis

Abstract

This study aims to discriminate the geographical origin of Thai Hom Mali rice in order to protect consumers from mislabeling. Stable isotopic and elemental compositions (δ13C, δ15N, δ18O, As, Br, K, Mn, Rb, and Zn) of Thai Hom Mali rice cultivated inside and outside the Thung Kula Rong-Hai Plain were combined with chemometric analysis, linear discriminant analysis (LDA) and partial least squares-discriminant analysis (PLS-DA). The 9 variables combined with LDA can distinguish Thai Hom Mali rice cultivated inside and outside the Thung Kula Rong-Hai Plain with 98.2 % correct classification and 94.6 % cross-validation. The efficiency in using stable isotopic and elemental compositions combined with soft PLS-DA was achieved 100 % in discrimination of Thai Hom Mali rice cultivated inside and outside the Thung Kula Rong-Hai Plain. The variables δ15N, Br, K, and Rb were key parameters to discriminate the geographical origin of Thai Hom Mali rice.

Keywords

• Geographical origin
• Thai Hom Mali rice
• Stable isotope
• EA-IRMS
• Elements
• INAA