Traceability Of The Geographical Origin Of Inner Mongolian Mutton By Carbon And Nitrogen Stable Isotope

Inner Mongolia is rich in natural grazing quality mutton,and some famous mutton species have been certified by geographical indications protection products.In recent years,for the protection of ecological environment and production increasing,some areas had started drylot and semi-drylot feeding methods.However,the ecological costs of dynamic feeding methods are different,and so are the qualities of mutton.At present,Inner Mongolia mutton lack of scientific origin traceability and authenticity identification technology.A total of 396 lean meats of longissimus dorsi,biceps femoris muscle,arm triceps and abdominal under muscle parts of 99 sheep were collected from 12 farming and animal husbandry counties in eastern and western Inner Mongolia.The values ofδ¹³C andδ¹⁵N were determined by elemental analyzer-isotope ratio mass spectrometry（EA-IRMS）.Results showed that there was no significant differences in the ratio ofδ¹³C andδ¹⁵N in the four parts,;theδ¹³C of grazing and yard feeding was distinct（P<0.05）,and could be distinguished between the three counties of the western areas,but could not be distinguished among the grazing mutton;theδ¹⁵N value had a significant difference（P<0.05）,but it could not be distinguished among all county samples.It is definite to distinguish grazing mutton in Hulun Buir and Xilingol areas from drylot mutton in Siziwangqi,linden county and Dalate flag through the values ofδ¹³C andδ¹⁵N conduceted by two-dimensional map projection and layer cluster analysis.There is obvious separation trends in some flag counties of the grazing area,but the longitude and latitude regularity are not found in this time.In conclusion,stable isotopeδ¹³C andδ¹⁵N values can partly distinguish the samples from each county.The results of this study supplied the technical and therological reference of traceability of the geographical origin of meat productes by carbon and nitrogen stable isotope.