Starch commercial acid hydrolysis

During hydrolysis, both 1,4 and 1,6 linkages are cleaved, converting the starch molecule to increasingly lower molecular weight products. A typical residence time in the converter is 5-10 minutes for low DE syrups high DE syrups may require 15-20 minutes at the necessary temperature. It is important to keep the conversion time short to prevent unnecessary color development. A typical commercial acid converter system is shown in Figure 21 A.22... 

The enzymatic hydrolysis of starch to glucose is commercially preferred to the acid hydrolysis route using hydrochloric acid. The enzymatic process produces fewer sideprod-ucts, does not involve a corrosive acid, and allows the use of less pure starch products whose protein contaminants would, upon acid hydrolysis, give amino acids and browning reactions. 

Preparation. D-Glucose (often called dextrose commercially, because of its dextrorotation) is manufactured on a large scale by acid hydrolysis of starch, usually potato starch in Europe and com starch in the United States.96... 

Mandels et al. (22) found that glucose manufactured commercially by acid hydrolysis of starch contained sophorose as an impurity which is a powerful inducer of cellulase in Trichoderma viride. In the studies... 

The most commercially feasible hydrolysis method is the initial hydrolysis at 140°C for 30 minutes. This method hydrolyzes most of the starch and 72% of the hemicellulose. This leaves the cellulose and a portion of the hemicellulose to act as a carrier for the corn steep liquor and stillage to make corn gluten feed. The additional acid hydrolysis step creates a large amount of degradation products, which would be inhibitory to the ethanol fermentation, without giving a greater monosaccharide concentration. The enzyme hydrolysis step is not feasible without enzymes that contain activities specifically for the corn fiber hemicellulose matrix. These types of enzymes are not commercially available, or would be prohibitively expensive, therefore, enzyme hydrolysis of corn fiber is not currently commercially feasible. 

Definition Sugar obtained from the hydrolysis of starch commercial prod, is the natural D(+)-enantiomer monohydrate Empirical C6H12O6 Formula CHO(CHOH)4CH20H Properties Colorless cryst. orwh. gran, powd., odorless, sweet taste sol. in water, hot glac. acetic acid, pyridine, aniline si. sol. in alcohol, ether, acetone m.w. 180.18 (anhyd.) dens. 1.544 m.p.146-158C... 

The use of starch for the preparation of glucose syrups has led to a commercial success in the industrial production of this material [132], However, starch is chemically converted to dextrin or dextrose syrups. Crystalline dextrose (glucose) is the major product of the starch conversion industry from com, milo-maize, grain sorghum, and other vegetable starches with acid under pressure and at high temperature [133], Starch hydrolysis is an equilibrium reaction and depending upon the... 

The pure oligosaccharides were obtained by preparative liquid chromatography from partially hydrolyzed polymers. Mixture of maltodextrins is a commercial sample obtained by partial enzymic and acid hydrolysis of starch (Roquette, France) Mixture of isomaltodextrins is prepared by partial acid hydrolysis of dextran. Cyclodextrins are commercial samples from Aldrich. 

Commercially, maltodextrins are produced by acid hydrolysis, hydrolysis," or combined acid and enzyme hydrolysis of starches. 

Degradation of starches with malt diastatic enzymes (which contain a-and )S-amylase) depolymerize starch to give soluble starch . "Thin-boiling starches are produced by mild acid hydrolysis of starch. D-Glucose is produced commercially by the total acidic hydrolysis of starch. 

The final product was subjected to ferric chloride-hydrochloric acid treatment in the same manner as commercial glucose and starch. A linear carbon dioxide-time relationship was observed which was practically identical with that for starch. In other words purified cotton cellulose, on relatively complete hydrolysis, appeared to give glucose in a... 

Glidine, a commercial diabetic food which is prepared from wheat flour and contains over go per cent of protein, may be used as a satisfactory source of glutamic acid. If this is used, it is not necessary to wash in order to remove the starch. From 1130 g. of this material, by hydrolyzing with 2500 cc. of concentrated hydrochloric acid and working up as before, 275-285 g. of glutamic acid hydrochloride may be obtained. Usually, the product from glidine is more difficult to decolorize. It has been found that an ether extraction of the hydrolysis mixture, after removal of the melanin, improves the color of the final product. 

Converted starches, also called thin-boiling starches, are produced by degradation of the starch chains into small segments. They can be cooked in water at higher concentrations than native starches. Low-viscosity starches are needed in applications where a high solid starch paste with a pumpable and workable viscosity is required. There are four classes of commercial converted starches dextrins (hydrolysis in solid-state) acid-modified starches (hydrolysis in a slurry) oxidized starches and enzymically depolymerized starches. 

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). 

Maltodextrin is an acid or enzyme-catalyzed hydrolysis product of starch, which has a dextrose equivalent of < 20. Maltodextrins are GRAS substances (21 CFR 184.1444) and can be used as a fat replacer, texture modifier, or bulking agent in dairy products, salad dressings, spreads, sauces, baked goods, frozen meat, and frozen desserts. Most maltodextrins are derived from corn, potato, tapioca, and wheat starches. Some examples of commercial products are Paselli SA2, Maltrin, and Stellar. 

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