The parabens are esters of para-hydroxibenzoic acid. The two most common esters are methyl and propyl parabens, which are approved for food use in the United States under the GRAS classification. The maximum concentration allowed is 0.1 %. They are most active against yeasts and molds. Parabens are white powders with faint odor and fair solubility in water at room temperature. The solubility is greatly increased by heating the water to 160Â°F-180Â°F. Methyl paraben is more soluble in water but less effective against molds than propyl paraben. To balance these differences, mixtures of 2 to 3 parts of methyl paraben with 1 part propyl paraben are normally used. Important advantages of parabens are their effectiveness at higher pH values, from 3 up to 8, and stability to high and low temperatures, even to steam sterilization. Despite these properties, parabens are not as widely used as other antimicrobial agents, probably due to higher cost and flavor objections. Applications include bakery products (formulated without yeast), beverages, flavor extracts, food colors, fruit products, jams, jellies, preserves (artificially sweetened), gelatin, marinated and smoked fish, pickles, salad dressings, syrups, wine and olives. If preservatives are used in a food, they must be declared in the list of ingredients, along with a short explanation of intended use, such as "preservative", "mold inhibitor", "to retard spoilage".