稳定性同位素碳、氮在牛不同组织中的变化规律

稳定同位素分析是追溯食品来源的一种有效技术。本文主要探讨了在相同的饲养条件下，牛不同组织中碳、氮同位素组成的变化情况以及品种对其的影响。利用同位素比率质谱仪测定了不同部位脱脂牛肉、不同部位粗脂肪、牛尾毛、血液、肝脏及饲料中的δ13C值和δ15N值，并进行了统计分析。结果表明，品种因素不影响组织中的碳、氮同位素组成；肌肉不同部位、血液、肝脏、牛尾毛之间的δ13C值无显著差异，而肝脏中的δ15N值极显著地高于其它组织；不同部位粗脂肪间的δ13C值也无显著差异。结果说明稳定性同位素碳、氮在牛不同组织中的分馏效应是不一致的。

Changes of Stable Isotopes Carbon-13 and Nitrogen-15 in Different Tissues of Cattle

Stable isotope analysis is a potential tool for tracing food origin. The stable carbon and nitrogen isotope composition in different tissues of two varieties of cattle under the same culture condition were investigated. δ13C and δ15N values of different defatted muscle and crude fat, cattle tail hair, blood, liver and feed were determined by isotope ratio mass spectrometry, and statistical analysis was carried out. The results showed that stable isotopes of carbon and nitrogen composition was not affected by cattle variety; the δ13C values between different defatted muscle, blood, liver and cattle hair were not significantly different but δ15N value in the liver was much higher than other muscle and the δ13C values didn't show difference among all the crude fat samples. So these results indicated that isotope fractionation in the various tissue was discrepant.