Rubidium analysis as a possible approach for discriminating between Korean and Chinese perilla seeds distributed in Korea.

The aim of this study was to discriminate between Korean and Chinese perilla seeds by using inorganic elemental analysis data combined with orthogonal partial least squares-discriminant analysis (OPLS-DA). Inorganic element content data were obtained from 29 Korean and 11 Chinese perilla seed samples distributed in Korea. Using energy dispersive X-ray fluorescence spectroscopy, 11 species of inorganic elements were detected in the perilla seed samples and eight of them were quantified. The Rb content was selected as the variable to best discriminate between Korean and Chinese perilla seeds using an S-plot generated from OPLS-DA. An accurate range for the Rb content was determined using inductively coupled plasma-optical emission spectroscopy. The Rb content is remarkably higher in Chinese perilla seeds (8.7-19.0 mg/kg) than in Korean perilla seeds (0.0-7.6 mg/kg), thereby suggesting that Rb analysis may be an appropriate approach to discriminate Chinese perilla seeds from Korean perilla seeds.