| 摘要 |
A chemically modified starch sulphate is prepared by reacting, in an aqueous system at a pH above 7, starch, a tertiary amine-sulphur trioxide compound and a chemical starch modifying agent whereby the starch is simultaneously sulphated and chemically modified. By the term "chemical modifying agent" is meant an enzyme, an oxidising agent, a derivatizing agent or a dextrinizing agent. The derivatizing step includes etherification and esterification and a variety of mixed derivatives may be produced, cyanoethyl starch sulphate and mixed phosphate-sulphate of starch being novel compounds. The process may be effected at room temperature or at any temperature up to the gelatinization temperature, or higher when salts are present to increase the gelatinization temperature. It is desirable that p the sulphation be limited to the range of 0,009 to 0,15 D.S. Trimethyl-amine- and triethylamine sulphur trioxides are the preferred sulphating agents but the sulphur trioxide compounds of other trialkyl amines and cyclic and heterocyclic tertiary amines may be used. The products are useful as gelling, thickening and emulsifying agents in foods, as textile sizes, paper coating agents, protective films and drilling mud adjuncts. In examples, (1) cyanoethyl starch sulphate is obtained from starch, acrylonitrile and trimethylamine-sulphur trioxide in water ; (3) Starch sulphate-phosphate ester is obtained from starch, sodium trimetaphosphate and trimethylamine-sulphur trioxide in water ; (2) a suspension of ungelatinized starch in gelatinized cyanoethyl starch sulphate is used to form protective films.ALSO:Fruit pie fillings are made by mixing the acid juice of canned sour cherries with a starch sulphate-phosphate mixed ester (see Group IV(a)) and sugar, heating the mixture to a boil and then adding the cherry meats. The fillings are then poured into pie crusts and baked. |
