Hydrophobically-modified silica aerogels: Novel food-contact surfaces with bacterial anti-adhesion properties

Abstract In the context of food safety, contamination of food-contact surfaces with pathogenic bacteria is a global concern. This work investigates the potential of hydrophobically-modified, silica aerogel as a bacterial anti-adhesion food-contact surface. The bacterial anti-adhesion efficacies of hydrophobic silica aerogel, hydrophilic silica (negative control), and hydrophobic silica (positive control) were evaluated using dip inoculation with Salmonella Typhimurium LT2 and Listeria innocua NADC 2841 at 8.8 to 9.1 log CFU/mL. After rinsing, cells on these surfaces were enumerated by conventional plating as well as direct counting via scanning electron microscopy (SEM). Compared with the negative control, the positive control and silica aerogel led to a reduced number of salmonellae by 1.2 ± 0.1 log units (93.23 ± 0.91%) and by 3.1 ± 0.1 log units (99.93 ± 0.01%), respectively via plate counting ( p L. innocua were 1.3 ± 0.0 (94.82 ± 0.21%) and 3.0 ± 0.0 (99.91 ± 0.01%) for the positive control and silica aerogel, respectively via plate counting ( p