Improved methods are provided for the treatment of foods to inhibit microbial growth therein, by the applying to or incorporating into the food a quantity of an alkali or alkaline earth metal salt of levulinic acid. The salts may be topically applied by spraying or dipping, or can be incorporated into the foods such as comminuted meat products. Preferred antimicrobial agents are the sodium and potassium salts of levulinic acid, applied or incorporated at a level of from about 0.5-4% by weight. A variety of foods may be treated in accordance with the invention, such as human foods (e.g., meats and cheeses) or animal foods (pet foods).