Fatty Acids Fingerprint And Discriminant Model Of Pasturing And Barn Feeding Beef Of Inner Mongolia

Inner Mongolia has a unique natural geographical environment and is rich in natural pasturing beef.In order to increase production and efficiency large-scale barn feeding is also rapidly developing.The difference of meat quality is caused by different feeding modes.However,Fatty Acids(FAs)fingerprint of beef and authentication model for pasturing from barn feeding lacks systematic study.A total of 148 pasture grazing,half barn-feeding and barn-feeding cattle biceps,dorsal longest muscle and subcutaneous fat on rib samples were collected from 10 banners/counties distributing east to west part of Inner Mongolia.FAs were determined by gas chromatography(GC)methods,and conducted descriptive statistics and chemometric cluster analysis,and establish and optimize the discriminant model of pasturing and barn feeding beef.FAs profiles of Inner Mongolia beef are different among feeding mode,region and the muscles.Three feeding methods have obvious clustering characteristics,but half-barn feeding cluster over laps either grazing and barn feeding beef samples.Optimizing Principal Component Analysis(PCA)parameters,cluster of pasturing and barn feeding beef can be separated,and this implies that FAs profiles of beef is feasible to establish authentication the model to discriminates pasturing beef from barn feeding.The n-3Polyunsaturated Fatty Acids(PUFA),α-C18:3n3(α-linolenic acid),α-C18:3n3,Trans Fatty Acid(TFA),C15:0,C17:0,C18:0 and C18:1n9t of pasturing beef were significantly higher than those in barn feeding beef,n-3 PUFAs increased 3.0 times,and α-linolenic acid increased 2.2 times,respectively.On the other hand,barn feeding beef contains significantly high n-6 PUFAs,C14:1,C16:1,C17:1,C18:1n9c and C18:2n6c(linoleic acid)than pasturing beef.The ratio of S: M: P in pasturing and barn feeding beef is 10:8:1 and9:11:1,the values of polyunsaturated fatty acids n-6/n-3 were 2.8 and 7.2,respectively.Clustering of geographical origins is consistent with clustering of feeding methods,in further analysis,clusters of two pasture grassland,Hulunbeier and Xilingol can be separated.Horqin Left Wing Rear Banner,Zhenglan Banner,Southern suburb of Hohhot and Uxin Banner clustering separately.The composition of FAs is different in three parts of biceps femoris,longissimus dorsi and subcutaneous fat on rib,but the difference between pasturing and barn feeding is the same.PCA of samples from three parts showed better discrimination between pasturing and barn feeding,and FAs of beef subcutaneous fat on rib had the longest clustering distance between pasturing and barn feeding,and had the best discrimination effect.SIMCA model was established by FAs of subcutaneous fat on rib,and the accuracy of internal and external verification is 100% and 94%,respectively.The pairing and compatibility tests could not distinguish the two feeding mode and the region difference.The cluster analysis and model based on chemometrics provide innovative ideals and methods for identifying the feeding systems of beef.