A method of using quaternary ammonium compounds for inhibiting attachment of and removing a broad spectrum of foodborne microbial contamination from food products. The method uses quaternary ammonium compounds for inhibiting attachment of and removing microorganisms such as, Staphylococcus, Campylobacter, Arcobacter, Listeria, Aeromonas, Bacillus, Salmonella, non-toxin-producing Escherichia, and pathogenic toxin-producing Escherichia such as O157:H7; fungi, such as Aspergillus flavus and Penicillium chrysogenum; and parasites, such as Entameba histolytica from a broad range of food. The foods that can be treated by this method are meat, seafood, vegetables, and fruit. One of the treatment methods is spraying quaternary ammonium compounds on the food products to prevent broad-spectrum foodborne microbial contamination. New formulations of quaternary ammonium compounds combined with glycerin and/or ethyl alcohol provides a concentrated formulation for industrial use and a diluted formulation for use in spraying methods.