GB774549A - Improvements in or relating to the production of dispersions in starch - Google Patents

Abstract

In making a cold water paint which will reconstitute with water, an aqueous slurry of a starchy substance capable of forming a solution of mono-dispersed molecules is cooked at above the normal gelatinization temperature with mechanical agitation to produce a clear solution of monodispersed molecules, the pigment is dispersed in this solution, and the dispersion is dried to particles, flakes or films in which the starchy substance constitutes a protective colloid for the pigment particles, and is clear, coherent and non-gummy. The starchy substances exemplified by roasted dextrins of 80 per cent or more solubility in water, thin-boiling hypochlorite- or peroxide-oxidized starches, hydroxyethyl, hydroxypropyl, methyl and ethyl derivatives of starch of a low degree of esterification and rendered thin-boiling by acid modification or oxidation, mixed carboxylic and sulphonic esters of starch and slightly acetylated starches of thin-boiling nature, waxy maize and waxy sorghum starches rendered thin-boiling by hydrolysis or oxidation, and acid or enzyme hydrolysed starches of dextrose equivalent 4-20, of high solubility in cold water, and giving only red to plum colouration with iodine. A substance which renders the dried starchy substances less friable and enhances its protective character, e.g. calcium chloride, glycerol, glycol, urea, dicyandiamide, ammonium thiocyanate, formamide, a glucose or maltose syrup, may be added, preferably to the cooked solution. A substance which assists dispersion of the pigment in the solution may be incorporated. U.S.A. Specifications 2,170,954 and 2,641,547 are referred to.ALSO:In imbedding a feed supplementary material, e.g. a vitamin A or b -carotene preparation, in a dry starchy matrix for protection against evaporation, bleaching, oxidation or rancidification, an aqueous slurry of a starchy substance capable of forming a solution of mono-dispersed molecules is cooked above the normal gelatinization temperature with mechanical agitation to produce a clear solution of mono-dispersed molecules, the material to be protected is dispersed in this solution, and the dispersion is dried to particles, flakes or films in which the starchy substance constitutes a protective colloid for the dispersed material, and is clear, coherent and non-gummy. The starchy substances may be derived from maize, tapioca, wheat, rice, sorghum, sago, potato and arrow-root, and are exemplified by roasted dextrins of 80 per cent or more water solubility, thin-boiling hypochlorite- or peroxide-oxidized starches, hydroxyethyl, hydroxypropyl, methyl and ethyl starches of a low degree of esterification rendered thin-boiling by acid modification or oxidation, slightly acetylated starches and mixed carboxylic and sulphonic starch esters of thin-boiling nature, waxy maize and waxy sorghum starches, rendered thin-boiling by hydrolysis or oxidation, and enzyme or acid hydrolyzed starches of dextrose equivalent of 4-20, of high solubility in water and giving only red to plum colouration with iodine. A substance which renders the dried starchy substance less friable and enhances its protective character, e.g. calcium chloride, a glucose syrup such as corn syrup, a maltose syrup, glycerol, glycol, urea, dicyandiamide, ammonium thiocyanate or formamide, may be added, preferably to the cooked solution. A substance which assists dispersion of the feed material may be added. Examples are concerned with making poultry feed supplements by plate drying and spray drying dispersions of xanthophyll oil from maize in prepared solutions of the starchy substances and corn syrup. U.S.A. Specifications 2,170,954 and 2,641,547 are referred to.ALSO:In preparing particles, flakes and films of materials imbedded in a dry starch matrix, there is employed an aqueous slurry of a starchy substance capable of forming a solution of mono-dispersed molecules, the slurry being cooked above the normal gelatinization temperature with mechanical agitation to produce a clear solution of mono-dispersed molecules, the material to be imbedded being dispersed in this solution, and the dispersion being dried to a product in which the starchy substance constitutes a protective colloid for the dispersed material and is clear, coherent and non-gummy. The starchy substances may be derived from maize, tapioca, wheat, rice, sorghum, sago and arrowroot, and are exemplified by roasted dextrins of 80 per cent or more water solubility, thin-boiling hypochlorite- or peroxide-oxidized starches, hydroxyethyl, hydroxypropyl, methyl and ethyl starches of a low degree of esterification rendered thin-boiling by acid modification or oxidation, slightly acetylated starches and mixed carboxylic and sulphonic starch esters of thin-boiling nature, waxy maize and waxy sorghum starches rendered thin-boiling by hydrolysis or oxidation, and acid or enzyme hydrolyzed starches of dextrose equivalent 4-20, of high solubility in water and giving only red to plum colouration with iodine. A substance which renders the dried starchy substance less friable and enhances its protective character, e.g. a glucose syrup such as corn syrup, a maltose syrup, glycerol, glycol, calcium chloride, urea, dicyandiamide, ammonium thiocyanate or formamide, may be added, preferably to the cooked solution. A substance which assists dispersion of the material may be incorporated. U.S.A. Specifications 2,170,954 and 2,641,547 are referred to.ALSO:In embedding materials in a dry starchy matrix, e.g., in diluting medicines, preparing plant-coating insecticides and in protecting dry spices, spice oils, diet supplements, vitamin preparations and fatty substances against deterioration by evaporation, bleaching, oxidation and rancidification, an aqueous slurry of a starchy substance capable of forming a solution of mono-dispersed molecules is cooked above the normal gelatinization temperature with mechanical agitation to produce a clear solution of mono-dispersed molecules, the material to be imbedded is dispersed in this solution, and the dispersion is dried to particles, flakes or films in which the starchy substance constitutes a protective colloid for the dispersed material, and is clear, coherent and non-gummy. The starchy substances may be derived from maize, tapioca, wheat rice, sorghum, sago, potato and arrowroot, and are exemplified by roasted dextrins of 80 per cent or more water solubility, thin-boiling hypochlorite-or peroxide-oxidized starches, hydroxyethyl, hydroxypropyl, methyl and ethyl starches of a low degree of esterification rendered thin-boiling by acid modification or oxidation, slightly acetylated starches and mixed carboxylic and sulphonic starch esters of thin-boiling nature, waxy maize and waxy sorghum starches rendered thin-boiling by hydrolysis or oxidation, and acid or enzyme hydrolysed starches of dextrose equivalent 4-20, of high solubility in water and giving only red to plum colouration with iodine. A substance which renders the dried starchy substance less friable and enhances its protective character, e.g. a glucose syrup such as corn syrup, a maltose syrup, glycerol, glycol, calcium chloride, urea, dicyandiamide, ammonium thiocyanate or formamide, may be added, preferably to the cooked solution. A substance which assists dispersion of the material may be added. Examples are concerned with (i) making vitamin A-containing flakes by plate drying a dispersion of an oil solution of vitamin A palmitate in a prepared solution of the starchy substance and corn syrup, (ii) making odourless flakes of rodent repellant by plate drying a dispersion of powdered crystals of aniline-trinitrobenzene in a prepared solution of the starchy substance and corn syrup, and (iii) making a free-flowing, non-greasy shortening preparation by plate drying an emulsion of melted vegetable shortening in a prepared solution of the starchy substance and corn syrup. U.S.A. Specifications 2,170,954 and 2,641,547 are referred to.