Soli in a food processing system is composed of both inorganic and organic matter, the latter in the form of proteins, fat or carbohydrates. The conditioning of food-contact surfaces with food residues (e.g., meat and fat soil) has been reported to stimulate attachment as bacterial cells attach to the meat residue, which builds up over time, or become trapped in fat that is strongly affiliated with contact surfaces (Hood and Zottola, 1995).