Cross-linked starches solubility

Colominic acid, a homopolymer of A -acetylneuraminic acid, has been cross-linked with soluble starch using epichlorohydrin to yield a gel which is useful for the affinity chromatographic isolation of neuraminidase. ... 

The specific activities of purified preparations of human parotid and pancreatic amylases towards Amylose Azure, Remazol Brilliant Blue starch, phosphate-derivatized starch, and cross-linked starch have been measured. The activities varied with the physical state of the substrate the parotid enzyme exhibited a higher specific activity towards all soluble starches, whereas the pancreatic amylase was more active towards insoluble chromogenic starches. Variations in the enzyme-substrate interactions support the view that there is a configurational difference between the amylases this may be useful in determining the proportions of these amylases in normal and pathological body fluids. 

Phadebas Method In this method [48], a blue-colored, cross-linked starch pol3rmer mixed with bovine senun albumin and a buffer substance is used as substrate. That product may be obtained from Pharmacia Diagnostics. It is suspended in water and hydrolyzed by the a-amylase, giving soluble blue fragments. At the end of the reaction, the unreacted compound is removed by filtration. The absorbance of the blue filtrate, measured at 620 nm, is a function of the a-amylase activity, which is determined from a standard curve. 

The affinity of an extracellular a-amylase from Streptomyces aureofaciens for cross-linked starches is affected by the presence of soluble substrates, the pH of the medium, and the presence of proteins. ... 

Cora Gluten Meal gluten de mais Com Oil huile de mais Com Stardi Production amidon de mais, procddds de fabrication Cora Steep Liquor extrait soluble de mais Cosmetics cosm6tiques Cotton coton Cotton Fiber fibre de coton Cottonseed Oii huile de coton Crambe chou d abassinie Cross-linked Starches amidon (f cule) reticuld... 

Some commercial durable antistatic finishes have been Hsted in Table 3 (98). Early patents suggest that amino resins (qv) can impart both antisHp and antistatic properties to nylon, acryUc, and polyester fabrics. CycHc polyurethanes, water-soluble amine salts cross-linked with styrene, and water-soluble amine salts of sulfonated polystyrene have been claimed to confer durable antistatic protection. Later patents included dibydroxyethyl sulfone [2580-77-0] hydroxyalkylated cellulose or starch, poly(vinyl alcohol) [9002-86-2] cross-linked with dimethylolethylene urea, chlorotria2ine derivatives, and epoxy-based products. Other patents claim the use of various acryUc polymers and copolymers. Essentially, durable antistats are polyelectrolytes, and the majority of usehil products involve variations of cross-linked polyamines containing polyethoxy segments (92,99—101). 

Carbonyl groups contribute to cross-linking reactions where hemiacetals are formed. These are the greatest influence on viscosity build-up when low oxidized starches are used at neutral to acidic pH. When highly oxidized starches are used, the influence of the carbonyl group is much less because the molecular weight has been lowered and solubility is increased. The complexity of the reaction is shown in Figure 1. 

However, the relatively high enzyme costs form an obstacle to commercialization. Inefficient laccase use is a result of its instability towards the oxidizing reaction conditions. We have recently shown that the stability of the laccase under reaction conditions can be improved by immobilization as a cross-linked enzyme aggregate (see Chapter 9). It has also been shown that a water-soluble iron complex of a sulfonated phthalocyanine ligand is an extremely effective catalyst for starch oxidation with hydrogen peroxide in an aqueous medium [11]. 

A template synthesis, by the cross link of water soluble starch with cyanuric chloride in a two-phase system (Equation (46)) provides a potential method for tailor-made cyclodextrins . Tailor-made cyclodextrins are believed to be applicable, more precisely and successfully, to many novel phenomena attained in the past by the use of cyclodextrin <83TL350l>. 

The reaction of polysaccharides ivith aldehydes to give cross-linked products has been known and exploited industrially for some time. Starch acetals may also be prepared by a method that does not give rise to cross-links and involves treatment of starch with a cyclic vinyl ether, 3,4-dihydro-2H-pyran, to give a tetrahydropyran-2-yl derivative (16). At low levels of substitution, the acetals are water-soluble, at... 

Wheat starch is composed of two components itself amylose, a linear, amorphous polymer and amylopectin, a branched, semicrystaUine polymer (10). The protein is known as gluten, also composed of two polymers, gliadin, a low-molecular-weight, soluble polymer and glutenin, a high-molecular-weight, cross-linked, elastic polymer primarily responsible for the viscoelastic properties of bread doughs. 

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