Enzymatic aqueous pretreatment composition for dishware

A pretreatment composition for dishware which comprises approximately by weight:

• (a) 0.05 to 2.0% of a thickening agent selected from the group consisting of xanthan gum, welan gum, rhamsan gum, guar gum, carboxymethyl cellulose, hydroxyalkyl cellulose, alkyl cellulose, polysaccharides with beta glycoside linkages, locust bean gum and maleic anhydride-methyl ether copolymers;
• (b) 0.1 to 0-9% of a calcium compound;
• (c) 0.01 to 1.0% of an antimicrobial preservative;
• (d) 0.1 to 5.0% of a buffer system comprising a mixture of boric acid, an alkali metal chloride and an alkali metal hydroxide;
• (e) 0.05 to 4.0% of at least one surfactant;
• (f) 0.2 to 4.0% of at least one enzyme stabilizer wherein said enzyme stabilizer has the formula YCO.sub.2 X, wherein Y is hydrogen or an alkyl group having about 1 to about 6 carbon atoms and X is an alkali metal cation;
• (g) 0.1 to 5.0% of at least one enzyme being selected from the group consisting of an amylase enzyme, alkaline protease enzyme or a mixture of said amylase enzyme and said alkaline protease enzyme, if said amylase enzyme and said alkaline protease enzyme are both present, then a weight ratio of said amylase enzyme to said protease enzyme being about 100 to 1 to about 1 to 10;
• (h) 0.1 to 1.0% of an alkali metal nitrate;
• and
• (i) balance being water, said composition at a concentration of 10 grams of said composition in one liter of an aqueous bath having a pH of about 6 to about 12, wherein the composition has a Brookfield viscosity at room temperature of about 100 to 600 cps at 10 rpms using a #1 spindle and the composition does not contain phosphate builders, nonphosphate builders excluding any present in said buffer system, organic builders, aliphatic glycols and aliphatic mono alcohols, or fatty acids or metal salts of fatty acids excluding any present in said antimicrobial perservative.