EFFECT OF AQUEOUS-ETHANOL CATIONIZATION ON FUNCTIONAL-PROPERTIES OF NORMAL AND WAXY STARCHES

Cationic starch ethers of normal and waxy corn, normal and waxy barley and normal pea starch were prepared by an aqueous alcoholic process f or evaluation of their functional properties as compared to the native starch controls. The native starches exhibited a wide range in averag e granule size (10-21 mu m diameter), amylose content (0-34%) and swel ling power (13-31). Cationization to degrees of substitution (DS) of 0 .030-0.035 with 3-chloro-2-hydroxypropyltrimethylammonium chloride res ulted in marked increases in swelling power of all starches, with litt le corresponding increases in starch solubility. Cationization also de creased the onset of endothermic transitions and pasting temperatures quite substantially, and promoted the development of sharp peak viscos ities in the amylographs of all normal and waxy starches, including th at of pea starch. Final cold viscosities of the cationic starches exhi bited positive setbacks, and the cooked starch gels, after storage for 7 days at 4 degrees C and -15 degrees C, showed no syneresis. All cat ionic starches except for waxy corn were more susceptible to alpha-amy lase hydrolysis than native control starches. The general improvement in functional properties, especially in the waxy corn, waxy barley and pea starches, due to the aqueous alcoholic-alkaline cationization pro cess would greatly enhance their industrial applications.