河南奶山羊乳酶活力和乳蛋白组分的研究

测定河南奶山羊乳的4种酶酶活力，并采用SDS-PAGE方法对乳中主要蛋白组分进行分析。结果表明：在初乳和常乳中4种酶酶活力分别为：γ-谷胺酰转肽酶(γ-GT)为322.46U/100mL和247.71U/100mL，碱性磷酸酶(AKP)为248.62U/100mL和200.14U/100mL，过氧化物酶(LP)为281.76U/mL和205.07U/mL，淀粉酶(AMY)为71.20U/100mL和22.15U/100mL。初乳中AKP活力显著高于常乳(0.01＜P＜0.05)，γ-GT、LP、AMY的活力极显著高于常乳(P＜0.01)。主要乳蛋白按分子质量由小到大均依次显示出乳清蛋白(α-La)、β-乳球蛋白(β-LG)、IgG-L(轻链)、酪蛋白(CN)、IgG-H(重链)、血清白蛋白(SA)等区带。在初乳和常乳中的含量分别为：α-La为4.52%和4.51%，β-LG为18.78%和9.59%，IgG-L为7.52%和3.95%，CN为11.29%和11.49%，IgG-H为6.95%和4.07%，SA为5.48%和5.39%。乳中β-LG相对含量较高，达到20.96%，α-La含量较低。初乳中的免疫球蛋白IgG(IgG-L、IgG-H)相对含量显著高于常乳(P＜0.01或0.01＜P＜0.05)，β-LG极显著高于常乳(P＜0.01)。乳球蛋白和免疫球蛋白随着泌乳天数的增加呈现明显的下降趋势，而其他蛋白变化不显著。乳蛋白组分的相对含量在山羊个体间存在差异。

Enzyme Activities and Protein Composition of Henan Dairy Goat Milk

The activities of four enzyme (γ-glutamyl transpeptidase, γ-GT; alkaline phosphatase, AKP; peroxidase, LP; amylase, AMY) in Henan dairy goat milk (a local variety of dairy goat in the west part of Henan province) was measured and the milk protein composition was determined by SDS-PAGE in this study. The results showed that the activities of r-GT, AKP, LP and AMY in colostrum and common milk of Henan dairy goat were 322.46 U/100 mL and 247.71 U/100 mL, 248.62 U/100 mL and 200.14 U/100 mL, 281.76 U/mL and 205.07 U/mL, and 71.20 U/100 mL and 22.15 U/100 mL, respectively. The activity of AKP was significantly higher in colostrums milk compared to common milk (0.01