Geographical origin of cereal grains based on element analyser-stable isotope ratio mass spectrometry (EA-SIRMS)

The stable carbon and nitrogen isotopic compositions (δ13C and δ13N) of different cereal grains from different regions were determined, using element analyser-stable isotope ratio mass spectrometry (EA-SIRMS) as the key method. Systematically, δ13C and δ13N of 5 kinds of cereal grains of different origins, 30 wheat samples from different cultivation areas and 160 rice samples of different cultivars from Guangdong province of China were examined. The results indicated that the δ13C values of rice, soybean, millet, wheat and corn were significantly (P < 0.05) different within different origins (Heilongjiang, Shandong and Jiangsu province of China), respectively, while δ13N values were not. Interestingly, there exists discrimination between these 5 kinds of cereals grains, no matter C-3 or C-4 plants. Further study showed that the δ13C values of wheat from Australia, the USA, Canada, and Jiangsu and Shandong province of China were also significantly (P < 0.01) different. Furthermore, the P-value test for 160 rice samples of 5 cultivars was not significant (P > 0.05), which indicated that the cultivar of cereal grains was not significant based on δ13C value. Thus, the comparison of δ13C would be potentially useful for rapid and routine discrimination of geographical origin of cereal grains.