Dextrins from Corn Starch

Subfractionation of Limit Dextrin MMV) from Corn Starch 

Acid Hydrolysis of Limit Dextrin, k X JfO in 2.S4 N Hydrochloric Acid at 100° 

Maltose Starch Limit dextrin preparation  

The specific rotation of the limit dextrins is lower than that calculated under the assumption that only maltose linkages occur. Maltotriose should have [a]u about -f 153°. 

The dextrin fraction MMIX was methylated. Vacuum distillation 

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We subject envelope and stamp adhesives to stringent safety requirements. Since we re likely to swallow traces of the stuff, we have to regulate it as a food. Gum arable from the acacia tree, dextrin from corn starch, and the water soluble resin polyvinyl alcohol are the adhesives we use most often. We also... 

Limit Dextrins from Corn Starch hy Action of Malt Extract... 

Fig. 1.—Formation of a White Dextrin from Corn Starch Changes in (1) Viscosity, in Centistokes, (2) Alkali Lability, and (3) Solubility, %, as a Function of the Conversion Time. (Redrawn from Ref. 5.)...

A Comparison of the Action of Purified Maltase-free Alpha Amylase from Malted Barley upon Corn Amylose, Corn Starch and upon Beta Dextrins Formed from Corn Starch by the Action of Beta Amylase (Data of Myrbdck and Thorsellu)... 

An interesting comparison is also given in Table XI86 of the action of malted barley alpha amylase upon corn starch, beta dextrins obtained from corn starch by the action of beta amylase, and upon corn amylose prepared according to the method of Meyer.6 90 These data show that, with equivalent amounts of enzyme, amylose was hydrolyzed much more rapidly and more extensively than unfractionated corn starch. Although the beta dextrins were hydrolyzed by this amylase, they were hydrolyzed much more slowly and less extensively than either of the other two substrates. These results are similar to those already considered for pancreatic amylase.41 64... 

Dextrine (produced from corn starch), for example, has been widely used as a binder in the fireworks industry. Water is used as the wetting/activating agent for dextrine, avoiding the cost, environmental issues, and hazards associated with the... 

A clear, viscous, syrup produced by the hydrolysis splitting—of potato starch with heat and acids, or enzymes. It contains dextrins, maltotetrose, maltotriose, maltose, and dextrose (glucose). The amount of each depends upon the conditions and duration of the hydrolysis. Corn syrup, derived in the same manner from corn starch, is more common in the United States. 

Of the myriad of modified starch systems tested, ranging from simple enzymically dextrinized starches to covalently attached amino acids and peptides onto dextrinized and/or oxidized (hypochlorite or periodate) corn starch bases, two polymers were selected as holding promise. The first system was a low dextrose equivalent (DE 5.7) enzyme-modified corn starch. The second starch-based polymer developed was a periodate-oxidized, amylase-dextrinized, covalently-attached phenylalanine glycoamine. 

Commercial dextrins are specifically the oligomers of starch. White dextrins, so called because of their visual appearance, are produced from a 30-40% suspension under the mildest possible hydrolysis conditions (79-120°C for 3-8 h in 0.2-2% H2S04 or HC1). Yellow dextrins and British gums are the partial hydrolysates at higher time-temperature integrals. Maltodextrins, dextrose equivalent20 5-19, derive from controlled enzyme or acid partial hydrolysis of gelatinized corn starch. The 20-24 dextrose equivalent hydrolysates tire com syrups (Appi, 1991). 

D-GIucose, 2,3,4-trimethyl-, III, 96 from methylated corn starch, III, 297 from methylated dextrin, III, 293 D-GIucose, 2,3,4-trimethyl-, and derivatives, V, 172-175 anilide, V, 175 a-1,6-di-azobenzoate, V, 175... 

Getting ethanol from corn consists of five steps grain grinding, mash cooking, starch liquefaction, saccharification and fermentation, followed by ethanol separation and dehydration. Before fermentation, the starch has to be converted to soluble dextrin by liquefaction in the presence of specific enzymes, such as a-amylase. This process takes place at temperatures above 100 °C at suitable pH and residence time. Then, another enzyme glucoamylase is added that transforms the... 

Dextrin.—Dextrin is a carbohydrate made from starch (chiefly from corn or potato starch) by the application of heat (yellow dextrin) or by treatment with both heat and acids (white dextrin). It forms a paste with water, the yellow variety tending to swell up and dissolve much more readily than the white. When examined microscopically in alcohol mounts, the grains, while conforming in general outline to those of the type of starch from which the dextrin was prepared, nevertheless show more conspicuous striations and clefts.. Corn dextrin shows distinct striations, whereas striations Digitized by Microsoft ... 

In America, the main source material of sugars and syrups from starch is corn starch. The starch is hydrolyzed to simpler chemical substances through the action of dilute acid—generally hydrochloric acid—under heat and pressure in a converter. The products of hydrolysis products are dextrin, maltose, and dextrose. As the hydrolysis progresses, the content of dextrose increases at the expense of the others. The conditions of the conversion are regulated according to the amount of dextrose required in the product to be produced. 

Dextrin A modified (hydroiyzed) starch usuaily from corn or potatoes. 15 3... 

The 7-dextrin is isolated from an enzymolysate of 5% potato or corn starch paste and macerans amylase prepared in a manner similar to that for dextrin. However the reaction is allowed to proceed in the absence of precipitant although thymol is added to inhibit extraneous bacterial growth. The final digest is concentrated to about one-fourth the original volume and cyclic dextrins are precipitated with trichloroethylene. The precipitate is dissolved in hot water to about 25% solids concentration and allowed to stand at room temperature for 24 hrs to remove the less soluble dextrin. The precipitated dextrin is removed by filtration and the clear filtrate is diluted to about 3% solids. The y-dextrin is precipitated with bromobenzene. The y-dextrin is collected, dissolved in boiling water and concentrated to about 20% solids. 

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