定量分析加热后乳清蛋白与酪蛋白的结合

Quantification of the association between whey proteins and casein micelle in heated reconstituted skim milk

将复原脱脂乳在 70～ 90℃范围内加热 1 0～ 2 5min后 ,用超速离心分离出酪蛋白微粒 ,并用毛细管电泳法定量分析。结果显示 ,β-乳球蛋白更容易结合到酪蛋白微粒上。当加热条件为 70℃、1 0 min时就有相当多的 β-乳球蛋白发生了这种结合 ,这时酪蛋白微粒中没发现任何 α-乳清蛋白 ,只有当加热温度大于 75℃时才有少量 α-乳清蛋白与酪蛋白微粒结合。复原脱脂乳经 90℃、2 5min加热后几乎所有 β-乳球蛋白都已转入酪蛋白微粒部分 ,而只有近 50 %的α-乳清蛋白转入酪蛋白微粒。

Reconstituted skim milk samples were heated at temperatures ranging from 70～90℃ for 10 to 25 minutes.After ultracentrifugation casein micelles were seperated and analyzed by capillary electrophoresis.Results show β\|lactoglobulin was more liable to associate with casein micelle.Substantive β\|lactoglobulin was found in micelles after heating at 70℃ for 10 minutes,while no α\|lactalbumin was present at the moment.The presence of α\|lactalbumin in micelle occurred only when the heating temperature was higher than 75℃.Heating at 90℃ for 25 minutes caused transferration of almost all β lactoglobulin and about half of α\|lactalbumin into casein micelle.