Antifouling amphiphilic silicone coatings for dairy fouling mitigation on stainless steel

Abstract

Pasteurization of dairy products is plagued by fouling, which induces significant economic, environmental and microbiological safety concerns. Herein, an amphiphilic silicone coating was evaluated for its efficacy against fouling by a model dairy fluid in a pilot pasteurizer and against foodborne bacterial adhesion. The coating was formed by modifying an RTV silicone with a PEO-silane amphiphile comprised of a PEO segment and flexible siloxane tether ([(EtO)₃Si-(CH₂)₂-oligodimethylsiloxane_m-block-(OCH₂CH₂)_n-OCH₃]). Contact angle analysis of the coating revealed that the PEO segments were able to migrate to the aqueous interface. The PEO-modified silicone coating applied to pretreated stainless steel was exceptionally resistant to fouling. After five cycles of pasteurization, these coated substrata were subjected to a standard clean-in-place process and exhibited a minor reduction in fouling resistance in subsequent tests. However, the lack of fouling prior to cleaning indicates that harsh cleaning is not necessary. PEO-modified silicone coatings also showed exceptional resistance to adhesion by foodborne pathogenic bacteria.

Keywords:

• Antifouling
• amphiphilic
• dairy processing
• durability

Acknowledgements

The authors would like to thank Université de Lille, the Région Hauts-de-France and the Texas A&M Engineering and Experiment Station (TEES) for supporting this project. M.E.B. thanks the Beckman Scholars Program. The SEM and Electron Probe Microanalyzer (EPMA) facilities in Lille are supported by the Conseil Régional des Hauts de France and the European Regional Development Fund (FEDER).

Disclosure statement

No potential conflict of interest was reported by the authors.