Sr isotope and trace elements analysis as a potential tool for determining the geographical origin of paprika

Sr isotope ratio and trace elements (Al, Ti, Mn, Fe, Ni, Cu, Zn, Rb, Sr) of 52 paprika samples (from Japan, Korea, New Zealand and Netherlands) were measured using inductively coupled plasma mass spectrometers of the double-focusing type and the quadrupole type, respectively. The relative standard deviation of the strontium isotope ratio (⁸⁷Sr/⁸⁶Sr) for a NIST SRM 987 standard was as small as 0.033% by optimizing the measurement conditions of the device. The obtained data were statistically evaluated so as to investigate whether there was a significant difference between domestic and foreign products cultivated by nourishing solutions. Although domestic products were limited to two cultivated areas, a linear discriminant analysis (LDA) model allowed the discrimination of domestic and foreign products with high (domestic products) accuracy. Consequently, the present study has demonstrated that the production place of paprika cultivated by a nourishing solution can be estimated by the ⁸⁷Sr/⁸⁶Sr isotope ratio and the Sr concentrations.