Dairy products are an indispensable food in our lives. Protein is a major component of dairy products, and changes in the protein content greatly affect the quality and taste of dairy products. Proteomics is at the core of current post-genomics and systems biology approaches. In this paper, the concept, detection methods and data analysis methods of proteomics are reviewed, with emphasis on proteomic studies of differential proteomes in casein, milk fat globule membrane protein and whey protein, which are useful to distinguish dairy products from different sources. This review provide an effective working idea for authenticity identification and quality and safety assurance of dairy products.

An ultra-high performance liquid chromatography tandem triple quadrupole mass spectrometry (UPLC-MS/MS) method was established for the determination of six quaternary ammonium disinfectant residues in milk-containing food for special medical purposes. The sample was extracted with 80% acetonitrile in water and the extract was separated on a RRHD Eclipse Plus C₁₈ column, detected in the positive ion mode using an electrospray ionization source with multiple reaction monitoring (MRM), and quantified by matrix-matched standard calibration. The calibration curves for the six quaternary ammonium disinfectants was linear in the concentration range of 0.1–5.0 ng/mL with correlation coefficient higher than 0.9960. The limit of detection (LOD) was 0.5 μg/kg and the limit of quantification (LOQ) was 1 μg/kg. The recoveries were 72.8%-102.3% for spiked solid matrix samples, and 71.8%–100.8% for spiked liquid matrix samples with relative standard deviations (RSDs) in the range of 0.25%–3.88% and 0.19%–2.51%, respectively. The proposed method is simple, efficient, rapid, sensitive, and suitable for the qualitative and quantitative analysis of quaternary ammonium disinfectant residues in food for special medical purposes.