Stable isotopes verify geographical origin of Tibetan chicken

Abstract

Due to the particularity of origin area, the yield and price of Tibetan chicken are different from those in the plain areas, which leads to chickens from the plains being disguised as Tibetan chickens. In present study, Tibetan chicken and chicken from other four provinces in plain areas were distinguished by stable isotopes and chemometric methods. The cross-validation rate was 97.6%. Secondly, correlation between mean δ¹³C, δ¹⁵N, δ²H and δ¹⁸O values in chicken samples and environmentalparameters was investigated. These indicators are closely related to geographical environment. δ¹³C and δ¹⁵N values were positively correlated with longitude (R = 0.955) and altitude (R = 0.796), respectively. δ¹⁸O and δ²H values were negatively correlated with latitude (R = 0.903) and altitude (R = 0.938), respectively. At last, we used stable isotopes to trace Tibetan chicken from the different area of Tibet. When four stable isotope ratios were combined, we can distinguish them.

Keywords: Chemometrics; Environmentalparameters; Stable isotope; Tibetan chicken; Traceability.