HEATHER M. SHEWAN1*, MEILIANA SIAUW1, NAOMI VINDEN2, ANRAN DONG2, AMIR BEHESHTI1, KENG YIH CHEW3, JASON R. STOKES1, KIRSTY R. SHORT3, DEIRDRE MIKKELSEN2, BERTHOLD KOEHLER4, MATTHIAS REIHMANN4*

*Corresponding authors

1. School of Chemical Engineering, The University of Queensland, Brisbane, Queensland, Australia
2. School of Agriculture and Food Sciences, The University of Queensland, Brisbane, Queensland, Australia
3. School of Chemistry and Molecular Biosciences, The University of Queensland, Brisbane, Queensland, Australia
4. GELITA AG, Eberbach, Germany

Abstract

The surface adsorption of hydrolysed collagen protein (NOVOTEC® CB800) and its interaction with a range of surfactants, which result in its ‘easy-to-clean effect’ has been utilised to produce a unique surface cleaner with residual biocidal activity for 24 hours. The protein combined with anionic, non-ionic and cationic surfactants is able to form a stable surface film on a range of surfaces including glass, polymethylmethacrylate (plexiglass) and stainless steel. In the absence of protein, the surfactant is rinsed off the surface. These stable surface films remain after drying the surface. With the addition of water, protein-surfactant mixtures rehydrate and reorganise to form an active surface film. The active film contains residual biocidal activity against Gram-negative and Gram-positive bacteria and SARS-CoV-2 after 24 hours. The presence of the hydroxyproline-rich-protein enhances the residual biocidal effect, especially in the presence of rinsing or abrasion, such as that occurring in high-use areas.

INTRODUCTION
The innovative concept of utilising a highly hydrophilic protein surface film to provide an easy-to-clean effect has recently been demonstrated (1). The novel surface properties of the hydroxyproline-rich-protein-based additive NOVOTEC® CB800 enable it to adsorb to surfaces in the presence of surfactants and render the surface hydrophilic. The surface film partially dissolves during subsequent rinses, releasing surfactants that facilitate cleaning while a thin protein surface film remains. The recent coronavirus pandemic has shown that there is a need for residual antiviral surface protection that lasts beyond the moment in time when the product is applied to the surface. SARS-CoV-2 remains viable on smooth stainless steel and plastic surfaces for up to 7 days (2). However, it is readily inactivated with a range of well-known disinfectants including those used routinely in the food industry including bleach (1 %), chlorhexidine (0.05 %) and benzalkonium chloride (0.1 %) (2). Despite routine cleaning with these agents, surface transmission has still occurred, for example in food processing facilities (3). This suggests that there is a need ...