GB246098A - Method of producing crystalline dextrose from starch bearing materials - Google Patents

Abstract

246,098. Corn Products Refining Co., (Assignees of Newkirk, W. B.). Jan. 17, 1925, [convention date]. Glucose.-Crystalline glucose is obtained by incompletely melting glucose, which has been prepared from starch by the ordinary processes of conversion and crystallization, and subjecting the magma to final crystallization while keeping the solid phase dispersed through the liquid. In one method, impure anhydrous dextrose is incompletely melted and then crystallized with gentle agitation at about. 120‹ F. or above to favour the production of anhydrous crystals. The mass is next centrifuged, and washed. The tem. perature may be reduced, after a certain amount of solid dextrose forms, to increase the yield. In another form, impure hydrate glucose is incompletely melted and then crystallized as before but within the hydrate range of temperature (i.e. up to 105‹ F.) or at higher temperatures up to 130‹ F. The conditions under which the anhydrous or hydrate forms of alpha- or #-glucose are formed in the crystallization are also described. The production of block sugar by carrying crystallization up to, or nearly to the point of solidification and subsequently removing the mother liquor by centrifuging or pressing is also mentioned. Specifications 227,140 and 232,160 are referred to. The Specification as open to inspection under Sect. 91 (3) (a) comprises also the addition of hydrate seed crystals in the crystallization of the incompletely melted hydrate. Crystalline glucose is also prepared from the starch-converted glucose by bringing about supersaturation in a solution of such high purity that crystallization is initiated substantially as scon as supersaturation takes place. In one method the sugar which may be hydrate or anhydrous or a mixture of both, is completely melted to a density of 40‹ BÚ. or thereabouts, and then crystallized in motion at about 120‹ F. or above, anhydrous crystals being obtained without seeding. Seed crystals may be added under some conditions. As the solid phase increases the temperature may be lowered, causing more rapid crystallization. A lower initial temperature may also be employed if liberal feeding with anhydrous crystals is effected at the start. In another method the solutions employed consist of liquors of high purity, e.g. 93 per cent and higher, obtained by carrying out the conversion of the starch by acid, e.g. hydrochloric acid, in open vessels instead of under pressure or by starting with a starch suspension of lower density, e.g. 6‹ instead of 12‹ BÞ., or by using a shorter time for the conversion, e.g. 21-22 minutes. In a further method, the solutions consist of converted liquors of ordinary puritv mixed with re-melted glucose. From these liquors either the hydrate or anhydrous form of glucose can be prepared, according to the temperature employed in crystallization and the purity of the liquor used. the anhydrous form tending to crystallize out from the purer and the hydrate from the less pure liquors. This subject-matter does not appear in the Specification as accepted,