Abstract: This study established a fluorescence-based quantitative real-time polymerase chain reaction method for the detection of caprine-derived ingredients in milk powder. The specificity, sensitivity, and stability of the caprine-specific primers were evaluated. By linear fitting of the difference in cycle threshold (ΔCt) as a function of the mixing proportion between goat and horse milk powder, a calibration curve for the relative quantitation of caprine-derived ingredients in milk powder was established as follows: y = 0.720 9x + 5.651 9 (R2 = 0.987 5), and the minimum detection limit of this method was 0.000 1 ng/μL. The recoveries of the proposed method were 96.22%-112.00%, and the inter- and intra-group coefficient of variation was ≤ 0.79% and ≤ 1.77%, respectively.

Key words: goat milk powder; horse milk powder; real-time fluorescence quantitative polymerase chain reaction; adulteration detection

摘要： 基于实时荧光定量聚合酶链式反应建立了乳粉中羊源性成分相对定量检测方法。对羊引物进行特异性、灵敏度和稳定性实验。通过模拟不同质量浓度羊乳粉与马乳粉混合样本，根据其ΔCt值的函数关系进行线性拟合进而绘制标准曲线，建立乳粉中羊源性成分相对定量检测。结果显示，该方法最低检测限为0.000 1 ng/μL、标准曲线方程为y＝0.720 9x＋5.651 9（R2＝0.987 5）、回收率为96.22%～112.00%、组间变异系数≤0.79%、组内变异系数≤1.77%。

关键词: 羊乳粉；马乳粉；实时荧光定量聚合酶链式反应；掺假检测