Adhesion of Coagulating Protein (Casein) to Various Surfaces

Abstract

Adhesion of curdled milk to surfaces is a nuisance in some continuous cheese-making machines. It is also an example of a phenomenon of wider interest, namely that of adhesion between coagulating protein and solid surfaces. An understanding of the factors which influence it is an important step towards the ultimate objective of control. Adhesion in the system milk + rennet occurs most markedly when milk on the point of clotting is moved continuously over a surface. A means of producing a continuous supply of such milk is described, and results when the amount of adhesion to different surfaces was measured are given. Adhesion was considerable when the surface was metal or other hydrophobic material, but it was small with some hydrophilic polymers, e.g., regenerated cellulose in the form of dialysis tubing. Dialysis tubing in an experimental curd-making unit enabled it to function for long periods without difficulties due to adhesion.