摘要
目的:建立快速、简便测定鲜牛奶、转基因牛奶和人乳中乳铁蛋白的方法。方法:在对样品脱脂和去除酪蛋白时,水洗乳脂、酪蛋白以提高乳铁蛋白的回收率。通过十二烷基磺酸钠-聚丙烯酰胺凝胶电泳(sodiumdodecyl sulfate-polyacrylamide gel electrophoresis,SDS-PAGE)分离乳清蛋白,薄层扫描法定量。对电泳和薄层扫描的条件进行优化,电泳使用1.0mm×10齿的试样格、分离胶质量浓度12g/mL、分离电压100V、上样量5μL、染色3h、脱色2h;薄层扫描采取锯齿、双波长、透射的扫描方式,Y步长和摆幅宽分别为0.1mm和8mm。结果:可以分离不同来源乳中的乳铁蛋白、α-乳白蛋白和β-乳球蛋白;乳铁蛋白加标回收率分别为104.53%、108.37%,同板精密度RSD值为3.1003%和1.8151%,在100～2000μg/mL范围内呈线性关系,相关系数为0.9988和0.9990。结论:此方法可以用于3种乳中乳铁蛋白的测定。
The aim of this study was to develop a rapid and simple method for the determination of lactoferrin from fresh bovine milk,transgenic bovine milk and human milk.After removing fat by centrifugation and precipitating caseins by adjusting pH,the lactoferrin contents were separated by SDS-PAGE（100 V,12 g/mL gel,comb：1.0 × 10 teeth,5μL injection,staining for 3 h and destaining for 2 h）;and then the target fractions in the gel were examined by thin layer chromatography scanner（transmission,zigzag scan,dual wavelength,swing width： 8 mm,delta Y： 0.1 mm）.The results showed that good separation was achieved for lactoferrin（LF）,α-lactalbumin（α-La） and β-lactoglobulin（β-Lg） from three different sources.The recoveries for LFI（LF standard obtained from fresh bovine milk） in fresh bovine milk and LFII（LF standard obtained from transgenic bovine milk） in transgenic bovine milk across three spike levels were 104.53% and 108.37%,respectively.The intra-plate assay precision RSDs for LFI and LFII were 3.1003% and 1.8151%,respectively.The calibration curves of LFI and LFII displayed a good linearity within the range of 100 to 2000μg/mL,with a correlation coefficient of respectively 0.9988 and 0.9990.
出处
《食品科学》
EI
CAS
CSCD
北大核心
2011年第16期274-278,共5页
Food Science
基金
转基因生物新品种培育重大专项(2008ZX08007-001)
