Stable isotopic fingerprint of Sangyod rice

Sangyod rice is the geographical indication product of Phatthalung province in Thailand. In this work, the stable isotopic fingerprint of Sangyod rice samples was investigated using isotope ratio mass spectrometry. A total of fifty rice samples collected from ten districts in Phatthalung were analyzed for stable isotopic composition (δ¹³C, δ¹⁵N and δ¹⁸O). The range of δ¹³C, δ¹⁵N and δ¹⁸O values in rice samples was - 28.41 to - 26.81, + 3.06 to + 8.31 and + 23.46 to + 29.46 ‰, respectively. The highest mean δ¹³C value was observed for rice samples from Tamot whereas the lowest value was found for rice samples from Si Banphot. δ¹⁵N was highest in samples from Si Banphot and lowest in samples from Khao Chaison. Kong Ra showed the highest δ¹⁸O value. Pak Phayun had the lowest δ¹⁸O. Most Sangyod rice samples from Si Banphot can be distinguished from other cultivation areas by a scatter plot of isotopic values. (author)