Geographical traceability of wheat and its products using multielement light stable isotopes coupled with chemometrics

The present study was aimed to investigate the variation of stable isotopic ratios of carbon, nitrogen, hydrogen, and oxygen in wheat kernel along with different processed fractions from three geographical origins across 5 years using isotope ratio mass spectrometry (IRMS). Multiway ANOVA revealed significant differences among region, harvest year, processing, and their interactions for all isotopes. The region contributed the major variability in the delta C-13 parts per thousand, delta H-2 parts per thousand, delta N-15 parts per thousand, and delta O-18 parts per thousand values of wheat. Variation of delta C-13 parts per thousand, delta N-15 parts per thousand, and delta O-18 parts per thousand between wheat whole kernel and its products (break, reduction, noodles, and cooked noodles) were <0.7 parts per thousand, and no significant difference was observed, suggesting the reliability of these isotope fingerprints in geographical traceability of wheat-processed fractions and foods. A significant influence of wheat processing was observed for delta H-2 values. By applying linear discriminant analysis (LDA) to the whole dataset, the generated model correctly classified over 91% of the samples according to the geographical origin. The application of these parameters will assist in the development of an analytical control procedure that can be utilized to control the mislabeling regarding geographical origin of wheat kernel and its products.