Abstract:Ginseng goat milk powder is a dairy product made by mixing ginseng ultrafine powder with milk powder. An extraction and separation method was established and validated for the recovery, precision and stability. The liquid chromatography- Quadrupole-Time of Flight -mass spectrometry (LC-Q-TOF-MS) was used for the identification and quantification of saponin monomers. The method had good stability, high precision (1.28%) and high recovery (101.1-105.3%). Twenty saponin monomers were fingerprinted and identified with MS2, then the peak areas were compared in two milk powers. The content of saponin in ginseng milk powder obtained by dry preparation method (3.44±0.51 mg/g) was higher than that of ginseng milk powder obtained by wet preparation method (2.38±0.14 mg/g). However, the uniformity was poor. No obvious degradation components were found in the total ion chromatograms, which were consistent with total saponin results. Saponin monomers contents in two milk power were: Rg1 (11.22±3.1 μg/g v.s. 8.03±2.9 μg/g), Re (22.99±5.5 μg/g v.s. 18.91±0.38 μg/g), Rb1 (7.43±0.41 μg/g v.s. 4.83±0.14 μg/g), Rb2 (65.29±5.32 μg/g v.s. 58.21±3.15 μg/g), Rc (11.64±1.02 μg/g v.s. 8.80±0.92 μg/g), Rd (10.09±0.69 μg/g v.s.7.81±0.52 μg/g). The method can provide a basis for saponin detection in complex matrices in food field.
