GB641222A - Improvement in manufacture of modified starch - Google Patents

Abstract

A modified starch in the physical form of ungelatinized starch granules having the property of inhibited gelatinization when dispersed in water under normal gelatinization conditions is obtained by reacting ungelatinized starch with an ether forming reagent which contains two functional groups which form ether linkages with two hydroxyl groups of the starch molecules. Ether-forming reagents specified include aliphatic dihalides or epoxy halides such as propylene dichloride, dichloropentane, ethylene dibromide, glycerol dichlorohydrin, dichlorobutane, epichloro- and epibromo-hydrin. It is preferred that the starch be alkaline during the reaction which may be conducted either in aqueous solution or in the dry. Gelatinization prohibitors such as sodium sulphate may be present and the starch used may be converted before or after treatment as by forming a British Gum. In examples, epichlorohydrin in varying proportions is added to weak aqueous sodium hydroxide dispersions of (1) tapioca starch, (2), (3), (4) corn starch, (14) 60 fluidity acid-converted corn starch and (15) 40 fluidity chlorinated corn starch at room temperature for fifteen hours when the product is neutralized, filtered off and dried, in (5) glycerol dichlorohydrin is added to a weak aqueous sodium hydroxide dispersion of corn starch, in (6) dry corn starch, mixed with soda ash, sodium methylate, trisodium phosphate or borax and dichloropentane is heated at 75-85 DEG C. for 20 hours when the cooled product can be used with or without purification and in a similar fashion tapioca starch is treated with (7) propylene dichloride and (8) epichlorohydrin at 60 DEG C. and corn starch with (9) epichlorohydrin at 75 DEG C., in (10) tapioca starch is suspended in weak aqueous sodium hydroxide solution for 4-5 hours, filtered off, dried and treated with glycerol dichlorohydrin at 65 DEG C. for 6 hours, in (11) corn starch mixed with trisodium phosphate is heated at 400 DEG F. to convert to a British Gum, sodium carbonate and epichlorohydrin added when the heat is turned off and the product allowed to stand for 1/2 -1 hour, in (12) the product of (3) is converted to a British Gum by heating with trisodium phosphate and in (13) corn starch pretreated with alkali is blended with sodium methylate and 1,4-dichlorobutane and heated at 40-50 DEG C. for 24 hours in a sealed container.ALSO:Food preparations comprising salad dressing, puddings and pies contain starches modified by treatment with an ether-forming reagent which contains two functional groups (see Group IVb).