Geographic Determination of Sangyod Rice using Elemental Concentration and Stable Isotopes Combined with Linear Discriminant Analysis

Rice is a main food for Thai population and the major cash crop of Thailand.Sangyod rice is traditional rice variety of southern Thailand mainly grown in Phatthalung province and was also registered as the Geographical Indication (GI) and the European Protected Geographical Indication (PGI).The traceability of rice geographical origin has become the most important issue in safety, rice quality assurance, and consumer confidence from mislabeling and adulteration.Stable isotope analysis is a powerful technique for food traceability.This study aimed to discriminate rice origin between Phatthalung and Songkhla provinces that are adjacent provinces.The stable isotopes and elemental concentrations combined with linear discriminant analysis (LDA) and radar plot were also investigated.As the result, three variables (%C, 18 O and %O) were chemical indicators applied to discriminate the geographical origin of Sangyod rice grown in 2 contiguous provinces (Phatthalung and Songkhla).The classification of Sangyod rice origins was correctly accomplished 95.3% of their original groups and 92.1% of cross-validation.