How do proteolytic enzymes help detergents remove protein stains?

Proteinic stains—such as those from blood, milk, or egg—are typically water-insoluble and adhere strongly to fabric fibers, which prevents standard detergents from penetrating the stain effectively.1

Proteolytic enzymes help remove these stubborn stains by breaking down the long, complex protein molecules into smaller, water-soluble fragments like peptides and amino acids. By degrading the protein structure, these enzymes make the stain water-permeable or water-soluble. This process allows the detergent to successfully penetrate the material, disperse the stain, and wash it away along with other oily dirt.21