Compound-specific δ13C and δ15N analyses of fatty acids and amino acids for discrimination of organic, pesticide-free, and conventional rice (Oryza sativa L.). (15th June 2019)

• Record Type: Journal Article
• 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
• Is Part Of: Food chemistry. Volume 283(2019)
• Page Start: 305
• Page End: 314
• Publication Date: 2019-06-15
• Subjects: Organic rice -- Pesticide-free rice -- Conventional rice -- Compound-specific isotope analysis -- Chemometric model; Food -- Analysis -- Periodicals; Food -- Composition -- Periodicals; 664
• DOI: 10.1016/j.foodchem.2018.12.129
• Languages: English
• ISSNs: 0308-8146

Abstract

Highlights: This work focuses on the detection of incorrect or fraudulent organic rice labeling. Compound-specific isotope analysis was employed for organic rice authentication. Best results were achieved by OPLS-DA combined with δ 13 C/δ 15 N amino acid analysis. δ 13 Clysine was identified as the greatest contributor (VIP > 1) for all OPLS-DA models. Abstract: Herein, we improve the procedure for organic rice authentication using compound-specific δ 13 C and δ 15 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 15 Nbulk 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 13 Camino-acid and δ 15 Namino-acid values. δ 13 Cbulk was correlated with most δ 13 Cfatty-acid ( r ≥ 0.596) values, and δ 15 Nbulk was strongly correlated with most δ 15 Namino-acid ( 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 2 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.