Patent GB-807070-A (GB)
Title: Improvements in or relating to process for preparing new starch products and the resulting product
IPC: C08B31/06
Filed: 1955-08-19
Abstract: Chemically-modified starch sulphates are produced by reacting in an aqueous system starch and a tertiary amine-sulphur trioxide compound at a pH above 7, preferably above 10, and subsequently reacting the sulphated starch with a chemical starch modifying agent, i.e. an acid, enzyme, oxidizing agent, derivatizing agent or dextrinizing agent.  Any alkaline compound or compound producing alkali by hydrolysis or other chemical means may be used to catalyze the sulphation and to maintain the desired pH, e.g. alkali metal hydroxides, sodium phosphate, sodium carbonate and organic bases, such as quaternary ammonium bases and amines may be used.  The sulphation proceeds readily at room temperature but higher temperatures may be used and salts such as sodium sulphate, potassium sulphate, sodium chloride, sodium dihydrogen phosphate and sodium tartrate may be added to prevent gelatinization.  40 DEG  C. is satisfactory for the production of an ungelatinized product providing the alkali does not exceed 0.1 mol. NaOH in a slurry of 1 mol. of starch in 280 mol. of water. The optimum D.S. level of 0.009 to 0.15 is obtained using 0.01 to 0.16 mol. of sulphating agent per mol. of starch.  Suitable tertiary amine-sulphur trioxide compounds are those derived from trimethylamine, triethylamine, N,N - dimethylbenzylamine, dimethyl ethylamine, diethyl methylamine, tripropylamine, diethylaniline, N - ethylpiperidine, N - ethylmorpholine, dimethylcyclohexylamine, and pyridine.  Acid treatment of the sulphated starch may be effected in conventional manner, preferably in the presence of salts, such as sodium or potassium sulphate, sodium chloride, sodium citrate, or sodium tartrate. The starch sulphate may also be modified with liquefying enzymes. Oxidizing agents such as alkaline hypochlorite solution, dry chlorine, or peroxides may be employed, if desired in the presence of salts to prevent gelatinization.  The derivatization of the starch sulphate may include esterification, e.g. formation of the acetate, or etherification, e.g. formation of hydroxyalkyl starches.  Both cereal and root starches may be used as starting materials.  The products form pastes of improved clarity, water holding capacity and stability against retrogradation.  Examples (1) and (6) to (11) describe the sulphation of starch using the sulphur trioxide compound of trimethylamine, triethylamine, N,N - dimethylbenzylamine or pyridine in an aqueous medium rendered alkaline with sodium hydroxide, sodium carbonate or trisodium phosphate, with or without the addition of sodium sulphate, followed by acid modification by means of dilute hydrochloric acid with or without the addition of sodium sulphate or sodium tartrate.  In Example (12), the acid-modified starch sulphate prepared in (11) is pregelatinized by cooking in water at 100 DEG  C. for 15 minutes and then dried on heated rolls (85 lbs. steam pressure).  Example (13) describes the treatment of waxy grain sorghum starch as in (1).  In Example (14) an aqueous slurry of starch is sulphated by means of trimethylamine-sulphur trioxide in the presence of sodium sulphate or sodium hydroxide, the air-dried product is gelatinized in water at 85 DEG  C. and then hydrolysed using the enzyme Rhozyme 713.  The products may be used for the preparation of gelatine-type desserts and pectin type jellies, as suspending agents and textile sizings.ALSO:N,N-Dimethyl benzylamine-sulphur trioxide, used in an example for the preparation of sulphated starch products, is prepared by adding chlorosulphonic acid dropwise to a chilled solution of N,N-dimethyl benzylamine in carbon tetrachloride with vigorous stirring, and after 1 hour the precipitate is filtered and washed with carbon tetrachloride and petroleum ether.  In a similar example, pyridine-sulphur trioxide is prepared by adding chlorosulphonic acid dissolved in chloroform to a chilled solution of pyridine in chloroform with vigorous stirring.ALSO:A gelling constituent for food preparations is a modified starch sulphate produced by reacting, in aqueous medium, starch and a tertiary amine-sulphur trioxide compound at a pH abvoe 7, and reacting the so sulphated starch with an acid, enzyme, oxidizing agent, esterifying agent, etherifying agent or dextrinizing agent (see Group IV (a)).  Examples are concerned with: a gelatine-like dessert comprising acid-treated starch sulphate, dextrose, sucrose, salt, tartaric acid, and "cherry" colour and flavour (Poncean dye-SX plus benzaldehyde) in water, the mixture being stirred for 3 minutes in a boiling water bath and poured into a glass mould to cool and set; a gelled salad, acid-treated starch sulphate, sucrose and citric acid, being stirred for 4 minutes in a boiling water bath, diced fruit, shredded lettuce and colour (2 drops of 1 per cent Guinea Green B in water) added, and the mixture poured into a glass mould to set; a gelled bouillon comprising acid-treated starch sulphate and strained beef broth, the mixture being cooked for 5 minutes in a boiling water bath and then cooled; a pectin-like jelly, acid-treated starch sulphate, water and sucrose being heated together in a boiling water bath, tartaric acid, sodium benzoate and an artificial grape flavour and colour added, and the mixture poured into a glass jar to set.