Abstract: System and method for applying an antimicrobial agent, such as acidified calcium sulfate (ACS), to unpackaged meat products, in order to eliminate or reduce existing food borne bacterial pathogens and to prevent their growth when the meat products are stored. A conveyor transports unpackaged meat products to a spray chamber having nozzles positioned above and below the conveyor and meat products. The conveyor can be a wire conveyor having wires having a thickness so that they can support the food items, which can be eight to ten pounds, while being small enough so that the they do not block ACS solution sprays from the bottom nozzles, or do so to a negligible degree. The lower nozzles spray ACS solution through apertures of the conveyor and onto at least the bottom surfaces of the unpackaged meat products. The solution is sprayed with a sufficiently high pressure and sufficiently small drop size so that the ACS solution penetrates into tissues of the unpackaged meat products.