*3.1.1 Sample preparation for 1DLC*

0.5 g milk powder samples were diluted in 2.0 mL ultrapure water. After 10 min of ultrasonication, 0.5 mL of Carrez I solution (500 mM aqueous potassium ferrocyanide), 0.5 mL of Carrez II solution (500 mM aqueous zinc acetate), and 1 mL of ACN were added in order to precipitate the proteins.
