内蒙古放牧和舍饲牛肉矿物质指纹特征

Mineral Fingerprint Characteristics of Pasture-fed and Barn-fed Beef in Inner Mongolia

为系统评价不同饲养方式牛肉的矿物质特征,从内蒙古自东向西8个旗县采集放牧和舍饲牛股二头肌和背最长肌样品共80份,测定其中27种样品矿物质元素含量,并进行主成分分析。结果表明:各旗县牛肉按照放牧和舍饲2种饲养方式或地区聚类,饲养方式聚类较地区聚类更明显;地区聚类与饲养方式聚类趋势一致,放牧旗县与舍饲旗县分别聚类;进一步分析表明呼伦贝尔和锡林郭勒2个放牧地区分离,科尔沁左翼后旗、正蓝旗、呼市南郊和乌审旗4个舍饲旗县分别单独聚类。股二头肌和背最长肌聚类部分重叠,有分离趋势。饲养方式、产地和肌肉部位矿物质的配伍方差分析和配对t检验差异不显著,常规统计对矿物质整体差异不敏感。放牧牛肉钾、镁、磷、钼、锰、镉、锂、锶、银、钡和铊含量显著高于舍饲牛肉,舍饲牛肉锌、硒、钴、铷和铯含量显著高于放牧牛肉。舍饲牛肉硒含量是放牧牛肉的2.1倍,且自东部向西部呈递增趋势。

A total of 80 samples of Biceps femoris and Longissimus dorsi muscles of pasture-fed and barn-fed cattle were collected from 8 banners/counties distributing from east to west in Inner Mongolia for the determination of 27 mineral elements,and principal component analysis(PCA)and descriptive statistics analysis were conducted on the data obtained.Results indicated cluster analysis showed better performance in discriminating among feeding systems than among regions despite consistent trends.Pasture-fed and barn-fed beef samples from different regions were clustered.Further analysis demonstrated that good separation was achieved between the pastures of Hulunbuir and Xilingol.Barn-fed beef samples from Horqin Left Wing Rear Banner,Zhenglan Banner,the Southern suburb of Hohhot and Uxin Banner were clustered separately.A tendency of separation between Biceps femoris and Longissimus dorsi samples was found despite a partial overlap.In paired analysis of variance(ANOVA)and paired t-test,no significant differences in the minerals were observed between feeding systems,geographical origins,and muscles,indicating that the conventional statistics is not sensitive to differences in minerals.The contents of K,Mg,P,Mo,Mn,Cd,Li,Sr,Ag,Ba and Tl in pasture-fed beef were significantly higher than those in barn-fed beef,while the contents of Zn,Se,Co,Rb and Cs in barn-fed beef were significantly higher than those in pasture-fed beef.The content of Se in barn-fed beef was 2.1 times higher than that in pasture-fed beef,and it showed an increasing trend from east to west in Inner Mongolia.