The Screening Of Marker For Geographical Origin Traceability Of Yak Meat

The analysis of stable isotope ratio and mineral element content is one of effective methods for food geographical origin traceability according to its theory.In order to probe into the feasibility and validity of the analysis of stable isotope ratio and mineral element fingerprint for yak geographical origin traceability,the yak meat samples were collected from He-nan county,Da-tong county of Qinghai Province、Hong-yuan county,Jiu-long county of Sichuan Province,Lu-qu county of Gansu Provence,Di-qing county of Yunnan Province and Ba-zhou county of Xingjiang,theδ¹³C、δ¹⁵N andδ²H values of yak meat were determined using isotope ratio mass spectrometry（IRMS）,the concentrations of Na,Mg,Al,K,Ca,Sc,V,Cr,Mn,Fe,Co,Ni,Cu,Zn,As,Se,Rb,Sr,Mo,Ag,Cd,Sn,Sb,Cs Ba and other mineral element in yak meat were measured by inductively coupled plasma mass spectrometry（ICP-MS）.Then the data of stable isotope ratio and mineral element content of different regions,and the influence of discriminant accuracy of regional combination of different age stages were combined with multivariate statistical methods and analysisde.The main results were as follows:（1）The result demonstrates that the stable isotope ratio and mineral element were significantly different among yak meat of different geographical origin at level of 0.05.In those single index,stable hydrogen isotopes provide potential indicators for tracing the origin of yak meat with 85%correct discrimination rate.When the indicators of stable isotope were comprehensively considerated,the effect of distinguish for yak meat from different places was better than individual indicator.Combined analysis of stable nitrogen and hydrogen isotopes provides potential indicators for tracing the origin of yak meat with accuracy up to 85%.By stepwise discriminating analysis three kinds ofδ¹³C,δ²H,Cd,Cs and Ti as indictors for origin traceability were selected.The combination of stable isotopes and mineral elements,and stable isotope ratio notablely improved the correct classification rate and had a better traceability effect on yak meat origin than mineral element methods.（2）In the use of isotope stability or mineral elements for geographical origin traceability,the samples with decrease ages will reduce the correct discriminant rate of samples from different regional source of yak meat.The combination of stable isotopes and mineral elements notablely improved the correct classification rate of different ages of yak meat samples.（3）The division of traceability scope can’t be single bounded with administrative areas,should fully consider feeding way,the influence of geographical environment,et.al.The multivariate statistical methods were essential tools for selecting the indicators and establishing the discriminant models in yak meat origin traceability.