Adsorption of Protein to Metal Surface and Removal of Adsorbed Protein by H 2 O 2 -electrolysis Treatment

Abstract

Proteins often adsorb tightly to metal sur faces. Such a tight adsorption of protein leads to fouling of the wall sur face of manufacturing equipment in food and drug manufacturing processes. The author has been engaged in the study of the adsorption behavior and mechanism of protein to metal (oxide) sur faces and the development of cleaning techniques that can remove adsorbed protein absolutely from metal sur faces under mild conditions. The results of the investigation to date have revealed that the electrostatic interactions via acidic amino acid residues of protein largely contribute to the tight adsorption. As for cleaning technique, a novel one that involves the use of hydroxyl radicals (・OH) generated by the electrolysis of hydrogen peroxide(H 2 O 2-electrolysis cleaning) has been developed. It was demonstrated that the irreversibly-adsorbed proteins on metal (oxide) sur faces (stainless steel, titanium, and etc.) could be absolutely removed within a few minutes by the H 2 O 2-electrolysis treatment at room temperature. The influences of various treatment factors on the removal behavior in H 2 O 2-electrolysis cleaning were investigated.