Patent GB-566236-A (GB)
Title: Improvements in and relating to the treatment of root starch
IPC: A23L1/0522
Filed: 1942-10-30
Abstract: Tapioca or other root starch is modified for use in pie fillings or jelly-like puddings of the Danish dessert type by treating it in aqueous suspension with a small amount of a water-soluble aldehyde, particularly formaldehyde or acetaldehyde, in the presence of a small amount of acid, preferably a mineral acid, or acid salt, such as sodium or potassium bisulphate, so that it will produce a gelatinizable paste of less viscosity, both when hot and cold, than the untreated starch, the gel being clear, transparent, tasteless and short, but not stringy or crumbly. The pH range may be about 1.6-2.5 and the amount of formaldehyde may vary from about .075-.5 per cent on the weight of starch. After treatment, the starch milk is neutralized with soda ash &c. and a water-soluble sulphite, e.g. sodium bisulphite is added to form with the excess aldehyde an addition compound, which is removed by filtering and washing.  The filter cake is resuspended in water, the pH adjusted by the addition of soda ash &c. and the starch is filtered and dried.  In one example, a 22 DEG  B<\>ae tapioca starch milk, to which dil. sulphuric acid has been added to adjust the pH to 1.6, is heated at 100 DEG  F. for 6 hours, .194 per cent formaldehyde being then added and the heating continued for 16 hours.  Soda ash is added to adjust the pH to 6 and the milk is filtered.  The filter cake is re-suspended in water at 115 DEG  F. to give a 12 DEG  B<\>ae suspension, .42 per cent sodium bisulphite is added and the milk is stirred for 75 mins. and filtered.  The filter cake is resuspended in water at 123 DEG  F. to 12 DEG  B<\>ae, the pH adjusted to 6 by addition of soda ash and the starch filtered and dried.  In the case of sweet potato starch, the preliminary acid treatment is omitted.ALSO:Tapioca or other root starch is modified for use in pie fillings or jelly-like puddings of the Danish dessert type by treating in an aqueous suspension with a small amount of a water-soluble aldehyde, particularly formaldehyde or acetaldehyde, in the presence of a small amount of acid, preferably a mineral acid, or acid salt, such as sodium or potassium bisulphate, so that it will produce a gelatinizable paste of less viscosity, both when hot and cold, than the untreated starch, the gel being clear, transparent, tasteless and short, but not stringy or crumbly.  The pH range may be about 1.6-2.5 and the amount of formaldehyde may vary from about .075-.5 per cent on the weight of starch.  After treatment, the starch milk is neutralized with soda ash &c. and a water-soluble sulphate, e.g. sodium bisulphate, is added to form with the excess aldehyde an addition compound, which is removed by filtering and washing.  The filter cake is re-suspended in water, the pH adjusted by the addition of soda ash &c. and the starch is filtered and dried. In one example, a 22 DEG  B<\>ae tapioca starch milk, to which dil. sulphuric acid has been added to adjust the pH to 1.6, is heated at 100 DEG  F. for 6 hours, .194 per cent formaldehyde being then added and the heating continued for 16 hours.  Soda ash is added to adjust the pH to 6 and the milk is filtered.  The filter cake is re-suspended in water at 115 DEG  F. to give a 12 DEG  B<\>ae suspension, .42 per cent sodium bisulphate is added and the milk is stirred for 75 mins. and filtered.  The filter cake is re-suspended in water at 123 DEG  F. to 12 DEG  B<\>ae, the pH adjusted to 6 by addition of soda ash and the starch filtered and dried.  In the case of sweet potato starch, the preliminary acid treatment is omitted. When the modified starch is required for puddings, a more severe aldehyde treatment may be given.  A pre-filling may be made by cooking the modified starch with sugar, egg yolks, butter and flavouring in water or with sugar and cherries in cherry juice, and a Danish dessert by cooking a mixture of the modified starch, anhydrous dextrose sugar, salt, tartaric, lactic or hydroxy acetic acid and flavouring in water.