Protein in milk exists in the form of

Protein in milk exists in the form of Colloidal.
Casein and whey protein are the major proteins of milk. Casein constitutes approximately 80% (29.5 g/L) of the total protein in bovine milk, and whey protein accounts for about 20% (6.3 g/L).
Casein is chiefly phosphate-conjugated and mainly consists of calcium phosphate- micelle complexes. It forms about 80% of the bovine milk proteins and forms large colloidal particles with calcium phosphate to form casein micelles.