Potassium sorbate is a salt of sorbic acid that is used in foods like cheeses, bread, sausages, and others to protect against yeast and molds. Sodium Benzoate is a salt of benzoic acid (an acid commonly found in foods like cranberries, prunes, and cinnamon) that is used as an antimicrobial in acidic foods like fruit juices, jams, and relishes.