稳定性碳、氮、氢同位素在牦牛产地区分中的应用

Stable Isotope Distribution of Carbon, Nitrogen and Hydrogen in Yak Meat from Different Regions

为确定稳定性同位素对牦牛肉溯源的可行性。利用同位素质谱仪测定来自青海省河南县、大通县,四川省红原县、九龙县的牦牛肉样品中粗脂肪的碳同位素及脱脂牦牛肉中的碳、氮、氢同位素。通过比较分析不同地域来源牦牛肉中稳定性碳、氮、氢同位素的组成特征。结果表明,各地区牦牛肉不同组织中的稳定性碳、氮、氢同位素存在显著差异(P<0.05)或极显著差异(P<0.01),脱脂牦牛肉中的稳定性碳同位素判别效果好于粗脂肪中稳定性碳同位素判别效果,同位素指标组合判别效果好于单一同位素指标的判别效果,稳定性氮、氢同位素指标组合分析是牦牛肉产地溯源的有效指标,准确率可达到85%。利用稳定性碳、氮、氢同位素指标与多元统计分析方法相结合可以对不同地域来源的牦牛肉进行有效的区分。

This study aimed to confirm the possible traceability of yak meat samples from different regions using stable isotopes. The δ13C, δ15N, and δ2H values of yak meat samples(muscle crude fat and de-fatted muscle) from Henan county and Datong county of Qinghai province, and Hongyuan county and Jiulong county of Sichuan province were tested using isotope ratio mass spectrometry(IRMS). The composition characteristics of δ13C, δ15N, and δ2H of yak meat samples were compared and analyzed. The results demonstrated that the δ13C, δ15N, and δ2H differed significantly among meat samples from different yak tissues(P < 0.05 or P < 0.01). The distinguishing capacity for de-fatted muscle was better than for muscle crude. When the indicators of stable isotope were taken into comprehensive consideration, yak meat samples from different places was better distinguished as compared to the individual indicators, and the combined analysis of stable nitrogen and hydrogen isotopes provided potential indicators for tracing the origin of yak meat samples with an accuracy up to 85%. It is a promising approach to classify yak meat based on δ13C, δ15N and δ2H combined with multivariate statistical methods.