CHEMICALS
^ Foods (frozen and canned) ^ Pharmaceuticals ^ Cosmetics ^ Ore Refining ^ Water Treating ^ Adhesives
Phosphate Gives Starch New Properties American Maize commercializes starch phosphates, aims them at food and industrial markets A new group of starch derivativesstarch phosphates—is going into commercial production at American Maize-Products, Hammond, Ind. Production now is on pilot plant scale, with a full-sized unit scheduled to be running before the year is out. Most likely uses for the new compounds: as thickeners in packaged (frozen and canned) foods; fillers and binders in pharmaceuticals; coagulants and binders in ore refining, water treatment, and adhesives. American Maize's entry into starch phosphates is based on process and use patents licensed from International Minerals & Chemical. According to IM&C patents, starch is reacted with phosphate salts (such as sodium, potassium, or lithium) to form the ester. American Maize uses mono- and disodium orthophosphates in its version of the process. The reaction works equally well with root starches (like potato starch) and cereal starches. In its own laboratories, American Maize finds that waxy corn (containing pure amylopectin) and high amy84
C&EN J U N E 27, 1960
lose corn phosphates can also be made. The Indiana firm, together with National Starch, pioneered commercialization of both types of corn.
Esters Are Water Soluble.
ing, which often breaks down their products. The starch phosphates, though, hold up much longer under these conditions. In canned foods, too, the esters have improved suspending qualities. In both types of products, they prevent curdling and formation of a sponge-like appearance. Thickening power of the starch phosphates compares with that of some vegetable gums currently in use, claims American Maize. And the gum-like properties of the phosphate esters could find use in pharmaceuticals and cosmetics. Dr. Evans speculates that the starch phosphates might compete with higher priced products like gum arabic, locust bean gum, and carboxymethylcellulose. Strong nonfood potential for the esters: ore refining. The new chemicals apparently work as coagulants during separation operations, also make good binders for pelletizing taconite ores (low-grade iron ore). Different Grades Available. American Maize is offering as its standard grade a highly substituted (8% to 10% phosphate on a weight basis), cold water soluble starch. It will supply other grades, which differ in the degree of phosphate substitution in the starch molecule and in purity, on request. The standard grade sells for I2V2 cents a pound, compared with 6V2 cents per pound for a comparable grade of regular corn starch. Higher purity, decolorized versions of the standard grade are also available. Expected price range for all eventual grades: 12 to 20 cents per pound.
Some
starch phosphates' properties differ markedly from those of starch itself. For example, starch phosphates dissolve in water. Normal starch, notes American Maize's Dr. James W. Evans, research and development vice president, doesn't dissolve in cold water, needs precooking before use. An aqueous solution of starch phosphates at room temperature is a gel. At higher temperatures, viscosity remains about the same. Different viscosities can be obtained only by changing the degree of phosphate esterification, or by treating the starch before phosphatizing it. The behavior of starch phosphates in water gives them a freeze-thaw stability unmatched by conventional starch, thus bodes well for their future food role. Normally, says Dr. Evans, frozen food manufacturers discourage frequent freezing and thaw-
Silvichemical Aims For New Outlets Rayonier's HT-120, extracted from western hemlock bark, works in cold-set adhesives Low-cost, cold-setting adhesives made by partially replacing resorcinol with an inexpensive bark extract (C&EN, June 13, page 47) could mean another commercially successful silvichemical for Rayon ier. The silvichemical is HT-120, a polyphenols intermediate extracted from the bark of western hemlock. Rayflo, Rayonier's other silvichemical, is also a western hemlock bark extract, is used as a dispersant for oil well drilling muds. It is produced at Vancouver, B.C.
