Patent GB-739173-A (GB)
Title: Cold water dispersible cold water soluble starch products and their production
IPC: C08B30/14
Filed: 1953-01-05
Abstract: A cold water dispersible, cold water soluble starch product suitable for use as laundry starch is obtained by subjecting starch to treatment by the following three steps in any order: (a) degrading the starch to a fluidity level within the range of about 40 to 90; (b) etherifying the starch by treatment with an etherifying agent in the presence of a starch etherification catalyst to a degree of substitution within the range of about 0.02 to about 0.1; and (c) completely gelatinizing the starch; the thus treated starch being then rapidly dried in the presence of about 3 to about 7 per cent of boric acid based on the weight of the starch (dry basis).  The degradation may be effected by acid hydrolysis, enzyme hydrolysis, or oxidation, and the degradation, e.g. in the case of acid hydrolysis or oxidation, may be carried p  out with or without gelatinization but when enzyme hydrolysis is employed pregelatinization of the starch is preferred.  The preferred etherifying agents are alkylene oxides, e.g. ethylene and propylene oxides, although other agents such as dimethyl sulphate may also be used.  Specified etherification catalysts are sodium hydroxide, sodium carbonate, lime, sodium chloride, triethanolamine and tetraethylammonium hydroxide.  Residual etherifying agent, catalyst, and soluble by-products may be removed by washing the starch with water on filters or centrifuges.  The starch should preferably be gelatinized with a minimum amount of water and the "Votator" (Registered Trade Mark) may be used for this purpose or a heated mixture of the starch and water may be pumped under high pressure through the feed orifice of a conventional spray drier.  For drying the etherified starch paste heated rolls are preferred and the dispersed starch should be dried as rapidly as possible directly after the final gelatinization.  Any type of starch, e.g. corn, wheat, grain sorghum, waxy maize, or tapioca, or mixtures thereof, may be used.  In examples (1) corn starch is treated with sulphuric acid in aqueous slurry at 125 DEG  F. until a portion of the reaction mixture when adjusted to pH 5.0 with sodium carbonate, filtered, and washed shows a fluidity of 75 and an intrinsic viscosity of 0.5.  The main portion of the starch is then neutralized, filtered, and washed and water is then added followed by sodium chloride and sodium hydroxide and the slurry transferred to a closed reactor into which ethylene oxide is introduced. After 6 hours hydrochloric acid is introduced to adjust the pH to 6.5 and the slurry is filtered and washed.  The starch which has been etherified to a degree of substitution (D.S.) of 0.073 hydroxyethyl groups per glucose group in the starch is then made into a slurry with water, 5 per cent of boric acid is added and gelatinization is completed in a "Votator" at 195 DEG  F. and the paste then led through a heated pipe to the valley between two steam heated rolls and the resulting dried starch flake is ground; (2) to (4) as in (1) except that the etherification is effected to a D.S. of 0.089, 0.064, and 0.024 respectively; (5) as in (1) except that the starch is degraded to a fluidity of 60 and an intrinsic viscosity of 0.60 and etherification is carried out to 0.061 D.S.; (6) as in (5) except that the starch is degraded to a fluidity of 40 and intrinsic viscosity of 0.90; (7) corn starch is etherified with ethylene oxide to a D.S. of 0.02, the product slurried with water, 5 per cent boric acid added, and the pH adjusted to 6.9.  Some calcium chloride and a commercial alphaamylose preparation ("Rhozyme DX") are then added and the slurry passed through a "Votator" at 195 DEG  F. and held in converting coils at 190 DEG  F. when the intrinsic viscosity drops to 0.60 and the starch is then passed to the valley of heated double rolls and finished as a dry powder; (8) as in (7) except that the etherification is carried out to a D.S. of 0.080; (9) corn starch is etherified with propylene oxide to a D.S. of 0.030 and the product is then suspended in water and 5 per cent boric acid added.  The pH is adjusted to 6.9 with hydrochloric acid and calcium chloride and "Rhozyme DX" added to convert the starch to an intrinsic viscosity level of 0.35 and the starch then dried; (10) starch of 75 fluidity is etherified with propylene oxide as in (9) to a D.S. of 0.042 and is then made into a slurry with water, the pH adjusted to 6.8 with hydrochloric acid, 5 per cent boric acid added, and gelatinization and roll drying effected; (11) corn starch is slurried with water at 75 DEG  F. and treated with sodium hypochlorite until the intrinsic viscosity is 0.60.  It is then filtered and washed and treated with ethylene oxide as in (1) to a D.S. of 0.079.  The product is then gelatinized and roll dried in the presence of 5 per cent boric acid.  The dispersibility ratings in cold water and the water spotting tendencies of the products are referred to and the cold water-solubility of some of the products are also given.  The methods used to determine the fluidity, degree of substitution (D.S.), cold water dispersibility, and cold water solubility are described. Specification 658,525, [Group V], is referred to.ALSO:A cold water dispersible, cold water soluble starch product suitable for use as laundry starch is obtained by subjecting starch to treatment by the following three steps in any order: (a) degrading the starch to a fluidity level within the range of about 40 to 90, (b) etherifying the starch by treatment with an etherifying agent in the presence of a starch etherification catalyst to a degree of substitution within the range of about 0.02 to about 0.1, and (c) completely gelatinizing the starch; the thus treated starch being then rapidly dried in the presence of about 3 to about 7 per cent of boric acid based on the weight of the starch (dry basis).  The degradation may be effected by acid hydrolysis, enzyme hydrolysis, or oxidation, and the degradation, e.g. in the case of acid hydrolysis or oxidation, may be carried out with or without gelatinization, but when enzyme hydrolysis is employed pregelatinization of the starch is preferred. The preferred etherifying agents are alkylene oxides, e.g. ethylene and propylene oxides, although other agents such as dimethyl sulphate may also be used.  Specified etherification catalysts are sodium hydroxide, sodium carbonate, lime, sodium chloride, triethanolamine and tetraethylammonium hydroxide.  Residual etherifying agent, catalyst, and soluble by-products may be removed by washing the starch with water on filters or centrifuges.  The starch should preferably be gelatinized with a minimum amount of water and the "Votator" (Registered Trade Mark) may be used for this purpose or a heated mixture of the starch and water may be pumped under high pressure through the feed orifice of a conventional spray drier.  For drying the etherified starch paste, heated rolls are preferred and the dispersed starch should be dried as rapidly as possible directly after the final gelatinization.  Any type of starch, e.g. corn, wheat, grain sorghum, waxy maize, or tapioca, or mixtures thereof, may be used.  In examples: (1) corn starch is treated with sulphuric acid in aqueous slurry at 125 DEG  F. until a portion of the reaction mixture when adjusted to pH 5.0 with sodium carbonate, filtered, and washed shows a fluidity of 75 and an intrinsic viscosity of 0.50. The main portion of the starch is then neutralized, filtered, and washed, and water is then added followed by sodium chloride and sodium hydroxide, and the slurry transferred to a closed reactor into which ethylene oxide is introduced to adjust the pH to 6.5 and the slurry is filtered and washed.  The starch which has been etherified to a degree of substitution (D.S.) of 0.073 hydroxyethyl groups per glucose group in the starch is then made into a slurry with water, 5 per cent of boric acid is added and gelatinization is completed in a "Votator" at 195 DEG  F. and the paste then led through a heated pipe to the valley between two heated rolls and the resulting dried starch flake is ground; (2) to (4) as in (1) except that the p etherification is effected to a D.S. of 0.089, 0.064, and 0.024 respectively; (5) as in (1) except that the starch is degraded to a fluidity of 60 and an intrinsic viscosity of 0.060 and etherification is carried out to 0.061 D.S.; (6) as in (5) except that the starch is degraded to a fluidity of 40 and intrinsic viscosity of 0.90; (7) corn starch is etherified with ethylene oxide to a D.S. of 0.02, the product slurried with water, 5 per cent boric acid added, and the pH adjusted to 6.9.  Some calcium chloride and a commercial alpha-amylase preparation ("Rhozyme DX") are then added and the slurry passed through a "Votator" at 195 DEG  F. and held in converting coils at 190 DEG  F. when the intrinsic viscosity drops to 0.060 and the starch is then passed to the valley of heated double rolls and finished as a dry powder; (8) as in (7) except that the etherification is carried out to a D.S. of 0.080; (9) corn starch is etherified with propylene oxide to a D.S. of 0.030 and the product is then suspended in water and 5 per cent boric acid added.  The pH is adjusted to 6.9 with hydrochloric acid and calcium chloride and "Rhozyme DX" added to convert the starch to an intrinsic viscosity level of 0.35 and the starch then dried; (10) starch of 75 fluidity is etherified with propylene oxide as in (9) to a D.S. of 0.042 and is then made into a slurry with water, the pH adjusted to 6.8 with hydrochloric acid, 5 per cent boric acid added, and gelatinization and roll drying effected; (11) corn starch is slurried with water at 75 DEG  F. and treated with sodium hypochlorite until the intrinsic viscosity is 0.60.  It is then filtered and washed and treated with ethylene oxide as in (1) to a D.S. of 0.079.  The product is then gelatinized and roll-dried in the presence o