Microbial contamination of peanut butter by Salmonella poses a significant health risk as Salmonella may
remain viable throughout the product shelf life. Effective cleaning and sanitation of processing lines are
essential for preventing cross-contamination. The objective of this study was to evaluate the efficacy of a
cleaning and sanitation procedure involving hot oil and 60% isopropanol, ± quaternary ammonium
compounds, to decontaminate pilot-scale processing equipment harboring Salmonella. Peanut butter
inoculated with a cocktail of four Salmonella serovars (~7 log CFU/g) was used to contaminate the
equipment (~75 L). The system was then emptied of peanut butter and treated with hot oil (90 C) for 2 h
followed by sanitizer for 1 h. Microbial analysis of food-contact surfaces (7 locations), peanut butter, and
oil were conducted. Oil contained ~3.2 log CFU/mL on both trypticase soy agar with yeast extract (TSAYE)
and xylose lysine deoxycholate (XLD), indicating hot oil alone was not sufficient to inactivate Salmonella.
Environmental sampling found 0.25e1.12 log CFU/cm2 remaining on processing equipment. After the
isopropanol sanitation (±quaternary ammonium compounds), no Salmonella was detected in environmental
samples on XLD (