Starch Hydrolytic products

Acid Reversion in Relation to Isomaltose as a Starch Hydrolytic Product, A. Thompson, M. L. Wolfrom, and E. J. Quinn,/. Amer. Chem. Soc., 75,3003-3004 (1953). Chemical Interactions of Amino Compounds and Sugars. VII. pH Dependency, M. 

How does the monosaccharide hydrolytic product of cellulose differ from the hydrolytic product of starch ... 

The unusual utility of this adsorbent has been demonstrated by its role in the preliminary isolation of isomaltose,maltotriose, maltotetra-086, = and panose > from the hydrolytic products of starch in the preparation of n-xylo-biose, -trio.se, -tetraose, -pentaose, -hexaose, and -heptaose from a partially hydrolyzed xylan in the resolution of bi-molecular dianhydrides of L-sorbose < and D-fructose < > in an improved procedure for the preparation of stachyose and in the preparation of a series of maltodextrins (as high as maltoheptaose) from the partial, acid... 

Dextrin, an intermediate hydrolytic product between starch and maltose sometimes present in plants. 

A source of alcohol and alcoholic beverages. The starch of grains, potatoes, etc., is first hydrolyzed by natural sprouting, as in the preparation of barley malt, or by the addition of malt to it. The hydrolytic products, glucose and maltose, are then fermented by the addition of yeast, containing the enzymes, maltase, and zymase, and alcohol is thus produced. This has been fully discussed in the chapter on alcoholic fermentation, (p. 95). 

A source of commercial glucose. Starch from various sources, e.g. corn, potatoes, etc., is hydrolyzed by boiling with dilute sulphuric acid, by which the final hydrolytic product, glucose, is obtained. It is ordinarily obtained as a thick syrup, corn syrup, or as a crystalline substance, glucose. Corn syrup as usually made is not pure glucose syrup but contains more or less of the intermediate products, dextrin and maltose. With these present the syrup does not crystallize even when very concentrated. 

Based on the mechanisms of enzyme hydrolysis of starch and the diffusion processes of enzyme and the starch digestion products in the plastic matrix, the following assumptions were made (a) the diffusion of both the enzyme and the products in the plastic matrix obeys the Pick s first law, (b) the diffusion coefficient is constant throughout the matrix during the reaction, (c) the hydrolytic reactions take place only inside the hydrophobic plastic matrix, and (d) the reaction between the enzyme and the substrate is a modified Michaelis-Menten type and the product (P), will competitively inhibit the enzyme activity ... 

On the basis of researches devoted to the products of paitial or total hydrolytic breakdown of methylated starch, the chain of a-D-anhydroglucose is thought to constitute the main element of the amylose and amylopectin molecules. These units are combined as in maltose, i.e. by means of a-glucosidic linkages formed between the carbon atoms 1 and 4 ... 

It is now supposed that gibberellic acid stimulates the hormonal production of a-amylase (and, probably, of /9-amylase and others) in the aleurone layer surrounding the endosperm starch-reserve. Gibberellic acid released 400 mg. equivalents of D-glucose per g. in 90 hours in wheat grains, with a maximum hydrolytic activity after 60 hours. The effect on /9-amylase was thought to be a release (to the extent of 85%) from the protein-bound, insoluble form.876... 

Pectinases These enzymes carry out the hydrolytic degradation of the D-glycosidic linkage in pectins. The latter substances, also known as pectic substances, are polymeric components of plant cell walls and. like starch, are composed of sugar residues linked by glycosidic bonds. The chemistry is the same as that shown for the amylases previously described. The main application of pectinases is in the production of fruit juices, wines, and certain other food products. 

Starch conversion refers to the process of converting starch into other products. It involves gelatinization, liquefaction, and saccharification. Liquefaction refers to the acid-or enzyme-catalyzed conversion of starch into maltodextrin. Starch, usually from wet milling of com, is pumped in a slurry to the conversion plant, where it undergoes one or more hydrolytic processes to yield mixtures of various carbohydrates in the form of syrups. The kind and amount of the various carbohydrates obtained depend upon the type of hydrolysis system used (acid, acid-enzyme, or enzyme-enzyme), the extent to which the hydrolytic reaction is allowed to proceed, and the type of enzyme(s) used. The fact that most starches consist of two different kinds of polymers... 

Another method was reported in 1919 for obtaining soluble starch by refluxing the starch granules in 95% ethanol, containing 0.2-1.6% (w/v) HCl for 6-15 min [141]. The product is called Small s soluble starch. It is soluble (10mgml ) in hot water and has a low reducing value due to the formation of ethyl-glycosides at the hydrolytic points. 

---