Characterization and Analysis of Differentially Expressed Proteins in Raw Milk during Cold Storage

Using data independent acquisition (DIA) proteomics, the composition and biological functions of differentially expressed proteins in raw milk during cold storage at 4 ℃ for up to 6 days were investigated. A total of 902 proteins were detected. Among them, 70 and 71 differentially expressed proteins were selected during the early (day 0 vs day 3) and late (day 3 vs day 6) stages of refrigeration, respectively. The differentially expressed proteins played an important role in the response to nerve growth factors and the regulation of cells and tissues at the early stage of refrigeration, and were mainly involved in the biological processes of cells. At the late stage of refrigeration, the differentially expressed proteins could regulate the metabolic processes of carbohydrate and RNA, and mainly participated in the sugar metabolic pathways. Protein-protein interaction (PPI) network analysis indicated that cell division control protein 42 homolog (CDC42) was the hub node protein for both refrigeration periods, which was closely related to phagocytosis. These findings revealed the compositional changes and functional diversity of functions in raw milk proteins during refrigeration, which will provide a theoretical basis for the cold storage of raw milk and be of great significance for the quality control of raw milk.