title: Effect of photocatalytic and hydrophobic coatings on brewery surface microorganisms.
abstract: The aim of this study was to determine whether process hygiene in the beverage industry could be improved by applying new coating techniques to process surfaces. Photocatalytic titanium dioxide (TiO(2)) and hydrophobic coatings applied to stainless steel with or without added  antimicrobial compounds were studied in laboratory attachment tests and in a 15-month process study. No clear reductions in numbers of attached microbes were obtained with photocatalytic coatings, except for coatings to which silver had been added. These TiO(2)+Ag coatings reduced  microbial coverage in laboratory studies and in some process samples. Hydrophobic coatings reduced the area coverage of microorganisms in 4-h laboratory studies but did not affect colony counts in laboratory or process studies. The surfaces had changed from hydrophobic into hydrophilic during  the process study. The coatings did not mechanically fully withstand process conditions; part of the hydrophobic coatings had peeled off, most of the precipitated Ag had dissolved, and some of the TiO(2) coatings were damaged. In conclusion, functional coatings have potential for  reducing microbial loads on beverage industry surfaces, but these coatings need further development.
authors: VTT Technical Research Centre of Finland, Espoo, Finland. outi.priha@vtt.fi
authors: O
authors: O
authors: Priha
authors: J
authors: J
authors: Laakso
authors: K
authors: K
authors: Tapani
authors: E
authors: E
authors: Levänen
authors: M
authors: M
authors: Kolari
authors: T
authors: T
authors: Mäntylä
authors: E
authors: E
authors: Storgårds
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D001419:Bacteria / Q000187:drug effects* / Q000254:growth & development; D001628:Beverages / Q000382:microbiology*; D018441:Biofilms; D015169:Colony Count, Microbial; D003257:Consumer Product Safety; D004203:Disinfection / Q000379:methods*; D005525:Food-Processing Industry / Q000592:standards; D006801:Humans; D057927:Hydrophobic and Hydrophilic Interactions; D008826:Microbial Sensitivity Tests; D012834:Silver / Q000494:pharmacology; D013193:Stainless Steel / Q000737:chemistry*; D013499:Surface Properties; D014025:Titanium / Q000494:pharmacology; D015032:Zinc / Q000494:pharmacology
chemical_list: D000900:Anti-Bacterial Agents; D013193:Stainless Steel; C009495:titanium dioxide; D012834:Silver; D014025:Titanium; D015032:Zinc