Peanut butter adsorption onto surfaces and surfactant selection in cleaning and the effect on allergen recovery

Abstract

Stainless steel and High-Density Polyethylene (HDPE) were fouled with suspensions of peanut butter and tested for their cleanability using cleaning solutions containing different surfactants. Following cleaning, protein allergen recovery from the surfaces was determined. The stainless steel was less rough (S_a = 162 nm) and less hydrophobic (-4.5 mJ/m²) than the HDPE surface (S_a = 3261 nm, −61.9 mJ/m², respectively). HDPE was cleaned more efficiently by Model cleaning solution B than Model cleaning solution A at all concentrations of peanut butter (0.001 % - 10 %). Recovery of the retained protein from the surfaces using Enzyme-Linked Immunosorbent Assay (ELISA) demonstrated that on the stainless steel, regardless of the cleaner or concentration used, no allergen was detected on the surface. The HDPE surfaces detected allergen from surfaces fouled with 10 % and 1 % peanut butter (5.12 ppm – 11.6 ppm and 0.01 ppm – 0.9 ppm, respectively). The recovery of allergens suggests an effect of the surface free energy and size of the surfactant molecules. Such findings are important when considering the selection of cleaners with respect to cleaning and allergen removal.