Compound-specific δ 13 C and δ 15 N analyses of fatty acids and amino acids for discrimination of organic, pesticide-free, and conventional rice (Oryza sativa L.)

• Published in: Food chemistry 2019-06, Vol.283, p.305
• Main Authors: Chung, Ill-Min, Kim, Jae-Kwang, An, Yeon-Ju, Kwon, Chang, Kim, So-Yeon, Yang, Yu-Jin, Yarnes, Christopher T, Chi, Hee-Youn, Kim, Seung-Hyun
• Format: Article
• Language: English
• Subjects: Amino Acids - analysis; Carbon Isotopes - analysis; Cluster Analysis; Discriminant Analysis; Fatty Acids - analysis; Least-Squares Analysis; Nitrogen Isotopes - analysis; Oryza - chemistry; Oryza - metabolism; Pesticides - chemistry; Principal Component Analysis
• ISSN: 1873-7072

Herein, we improve the procedure for organic rice authentication using compound-specific δ C and δ N analyses of fatty acids and amino acids, addressing the increasing demand for accurate methods to confirm organic authenticity. Organic rice (OR) and pesticide-free rice (PFR) featured higher values of δ N than conventional rice (CR), whereas the corresponding differences between OR and PFR were insignificant. Additionally, OR, PFR, and CR could be discriminated based on some δ C and δ N values. δ C was correlated with most δ C (r ≥ 0.596) values, and δ N was strongly correlated with most δ N (r ≥ 0.834) values. The first component in the orthogonal projection to latent structure-discriminant analysis model allowed for a clear separation between OR and PFR, and good predictability (Q Y = 0.506). Thus, the present study improves the reliability of organic authentication when bulk stable isotope ratio analysis alone is insufficient for the accurate discrimination of OR, PFR, and CR.