Starch metal hydroxides

During com wet-milling, a 40—50% soHds-starch suspension is treated with a metal hydroxide and ethylene oxide at approximately 50°C to produce DS of 0.1 and the product is purified by filtration and washing. 

The Requirement of a Divalent Alkaline Earth Metal. Lime-treated corn produces a dough whose functional properties depend on the pasting characteristics of starch. The hydroxides of different alkaline earth metals were tested to determine whether they could replace calcium in the nixtamalization process. It was not possible to prepare tortillas with adequate sensory or mechanical properties from corn treated with... 

As discussed next, barium salts form insoluble complexes with starch. Similar behavior is exhibited by the complex of Ca(OH)2 with starch. This property is utilized for the precipitation of starch from aqueous solution, a process that is rather slow.475,476 In his subsequent paper, Rakowski477 studied the effect of salts on the adsorption of metal hydroxides it was observed that increases in salt increased the adsorption of hydroxides. This effect is absent in the case of the adsorption of NH4OH. More extensive studies478 demonstrated the following order of adsorption capacities Ca(OH)2 = Ba(OH)2 > KOH > NaOH > LiOH > Me3(PhCH2) NOH > Me4NOH. Rakowski,466,468 Lloyd,463 and Leach etal.47S accordingly... 

Diffuse reflectance spectroscopy was used to screen the possible interactions between a large number of adjuvants and several dyes [23]. It was concluded that supposedly inert excipients (such as starch or lactose) were capable of undergoing significant reactions with the dyes investigated (Red No. 3, Blue No. 1, and Yellow No. 5). For adjuvants containing metal ions (zinc oxide, or calcium, magnesium, and aluminum hydroxides), the degree of interaction could be considerable. It was concluded from these studies that dye-excipient interactions could also be responsible for the lack of color stability in certain tablet formulations. 

Nitric acid. Sulfuric acid, 3,5-DichloranUine Hypochlorites (calciirm/sodium). Glycerin Hydrochloric acid. Aluminum metal Sodium hydroxide. Aluminum metal Sodium chlorate. Fuel oil Aluminum, Sulfur, Starch Sugar, Sodium peroxide... 

Starch can be vinylated with acetylene in the presence of potassium hydroxide in an aqueous tetrahydrofuran medium.1 1 The mechanism possibly involves the addition of the potassio derivative of starch across the carbon-carbon triple bond of acetylene, with subsequent hydrolysis of the organometallic intermediate to give the vinyl ether. Such a mechanism has been postulated for the formation of vinyl ethers from monohydric alcohols and acetylene, in the presence of an alkali metal base as catalyst.1 2 The vinylation of amylose is very similar to the vinylation of amylopectin, except for the relative ratio of mono- to di-substitution. With amylopectin, the proportion of disubstitution is greater. In both starches, the hydroxyl group on C-2 is slightly more reactive than the hydroxyl group on C-6 there is little substitution at the hydroxyl group on C-3. 

Other starch varieties chemically bind metal atoms only to the hydroxyl groups, in the same manner as alcoholates. Alkali metal starchates were obtained for the first time by the use of either metal amides in liquid ammonia641 or metals in liquid amines.642 These methods were subsequently used by others.643 Sodium 2-starchate could be prepared by refluxing an alcohol solution of NaOH and dry starch.644 The reaction of dry starch with controlled amount of NaOH in 1-butanol provided either monosodium 2-starchate or disodium 2,3-starchate.645,646 However, complexes of NaOH with starch were also characterized.37,38 Thallation of starch could be performed with thallous hydroxide.647... 

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