Potassium Metabisulfite is an ingredient that is added to a variety of products to act either as an antioxidant or to prevent microorganism growth. Some of these products are dried fruits, maraschino cherries, and lemon drinks. 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.