稳定同位素技术在肉羊产地溯源中的应用

【目的】通过比较不同部位羊肉中碳氮稳定同位素差异,以及对羊肉、全骨粉、脱脂骨粉与骨胶原的稳定同位素分析,为肉羊产地溯源鉴别提供技术支持。【方法】利用同位素比率质谱仪（IRMS）测定不同部位脱脂羊肉中δ¹³C和δ¹⁵N值,进而比较不同产地来源（新西兰和中国宁夏、甘肃、安徽）的羊肉、全骨粉、脱脂骨粉与骨胶原中δ¹³C和δ¹⁵N值,并对结果进行方差分析、线性判别分析与相关性分析,确定碳氮稳定同位素对肉羊产地的溯源能力。【结果】后腿、排骨与胸叉、腹腩、脖子中δ¹³C值具有显著性差异（P<0.05）,δ¹⁵N值在后腿、胸叉、排骨、腹腩和脖子5个部位间无显著差异（P>0.05）。不同产地（宁夏、甘肃、安徽和新西兰）的脱脂羊肉、全骨粉、脱脂骨粉与骨胶原中δ¹³C和δ¹⁵N值差异显著（P<0.05）,其中脱脂羊肉对产地溯源判别效果最佳,原始判别正确率为84.9%,交叉验证判别正确率为82.4%。全骨粉与骨胶原对产地判别正确率达65%以上。相关性分析结果表明脱脂羊肉、全骨粉、脱脂骨粉与骨胶原中δ¹³C、δ¹⁵N具有极显著相关性（P<0.01）,骨胶原与脱脂骨粉、全骨粉中碳同位素相关性最高,相关系数分别为0.903和0.866。【结论】稳定同位素可有效鉴别不同产地来源的肉羊样品,羊肉、全骨粉、脱脂骨粉及骨胶原中稳定同位素组成变化趋势基本一致,因此,利用稳定同位素技术对肉羊进行产地溯源是可行的。

Application of Stable Isotope Technology in the Origin Traceability of Sheep

【Objective】By comparing the differences of carbon and nitrogen stable isotopes in different parts of mutton and analyzing the stable isotopes of mutton, whole bone meal, de-fatted bone meal and bone collagen, the technical support was provided for the origin traceability identification of sheep. 【Method】Isotope Ratio Mass Spectrometer (IRMS) was used to determine δ ¹³C and δ ¹⁵N values in different parts of sheep, and δ ¹³C and δ ¹⁵N values in de-fatted mutton, whole bone meal, de-fatted bone meal and bone collagen of the sheep bones from different origins (New Zealand, and Ningxia, Gansu, Anhui, China). ANOVA test, linear discriminant analysis and correlation analysis were carried out on the results to determine the traceability of carbon and nitrogen stable isotope to the origin of sheep. 【Result】The δ ¹³C values of hind legs and ribs were significantly different from those of chest fork, abdomen and neck (P<0.05), and there was no significant difference in δ¹⁵N values among the five parts of hind legs, chest fork, ribs, abdomen and neck (P>0.05). The δ¹³C and δ ¹⁵N values of de-fatted mutton, whole bone meal, de-fatted bone meal and bone collagen from different origins (Ningxia, Gansu, Anhui and New Zealand) were significantly different (P<0.05). De-fatted mutton had the best effect on the origin traceability, with the original discrimination accuracy rate was 84.9% and the cross-validation discrimination accuracy rate was 82.4%. The accuracy rate of distinguishing the origin by whole bone meal and bone collagen was over 65%. The correlation analysis results show that de-fatted mutton, whole bone meal, de-fatted bone meal and bone collagen had extremely significant correlation (P<0.01), and the carbon isotope in bone collagen had the highest correlation with de-fatted bone meal and whole bone meal, with correlation coefficients of 0.903 and 0.866, respectively. 【Conclusion】Stable isotope could effectively identify sheep samples from different origins, and the change trend of stable isotope composition in mutton, whole bone meal, de-fatted bone meal and bone collagen was basically the same, so it was feasible to trace the origin of sheep by using stable isotope technology.