Oxidized starches production

Oxidized Starch Production Methods. Multiple methodologies were utilized to produce the corn starch products of hypochlorite and periodate oxidation. Ultimately only three of these procedures were selected as yielding functional product and will, therefore, be the only methods to be outlined here. 

Dextrose Equivalency. Corn starch dextrose equivalent values (de) were usedto measure the carbonyl groups present in both dialdehyde, oxidized starch production and the production of dextrinized starches (26). 

Sodium chlorite oxidation of com and rice starches is recommended for the production of textile sizes (101) and oxidized starch is recommended as a hardening agent in the immobilization of microbial cells within gelatin (102). 

The oxidation of starch in aqueous suspension with H202 in the presence of iron phthalocyanine gives both carboxylic and carbonyl groups (Table 3.1). The best yields were obtained with a molar ratio 12900/1 (0.0078 mol%), but the oxidation was still quite efficient with 0.0039 mol% of catalyst [25800 per anhydroglucose unit (AGU)/catalyst ratio]. The oxidized starch had almost the same final Fe-content as the initial potato starch. Still, the efficiency of this method in view of scaling up was limited by comparatively low activity and product isolation problems. 

Significant volumes of low oxidized starch are used at the size press. These starches are made by treatment in alkaline suspension with sodium hypochlorite so that from 1 to 2% active chlorine acts on the starch. The reaction is simple to perform. However, the reaction products are complex. Chain scission occurs at the same time that carboxyl and carbonyl groups are formed in the starch. It is most desirable to prepare the highest ratio of carboxyl to carbonyl as possible and this reaction is a function of the pH in the slurry. 

The focus of this work was to determine if a glyco-peptide or a simple dextrinized, oxidized starch could be produced which would enhance the behavior of a starch-based polymer for spray dried flavoring production. Enhancement of a starch s lipophilic/hydrophilic balance was anticipated to maintain the polymer s film forming" and cohesive wall development during the spray drying process while improving its emulsifying/interfacial activity capabilities. 

Substantial improvement (about 50%) of lemon oil encapsulation efficiency was attained for the covalently-linked phenylalanine-Oxidized starch wall material over the Oxidized starch control. In fact, this particular glycoamine resulted in lemon oil retentions following drying in the mini-spray dryer which surpassed both the Control and lipophilic starches (See Table IV). Dry blending phenylalanine with the Oxidized starch base exhibited the benefits associated with covalently linked glycoamine production via lemon oil vapor phase flux analysis. 

Oxidized Starches. Alkaline hypochlorite treatment introduces carboxyl and carbonyl groups, effects some depolymerization, and produces whiter (bleached) products that produce softer, clearer gels. Ammonium persulfate is used in some paper mills with continuous thermal cookers to prepare in situ bigb solids, low viscosity dispersions. Most of the hypochlorite-oxidized starch and all the ammonium persulfate-oxidized starch is used in the paper industry. The low solution viscosity and good binding and adhesive properties of these products make them especially effective in high solids, pigmented... 

Oxidation of Starch.97- 98- 114 Oxidation in Aqueous -Suspension. Ten grams of cornstarch or potato starch, previously dried at 100° for about twenty hours, is suspended in 290 cc. of 0.533 M aqueous periodic acid solution. After being shaken thoroughly, the mixture is kept at 20-25° for twenty-four hours. About one mole of periodic acid per C H oOs unit of starch reacts to yield oxidized starch (LYI). The product is filtered, washed free from iodic acid and excess periodic acid with cold water, and dried at 40-50°. The yield is quantitative. Over 99% of the substance dissolves in forty parts of water at 100° during two hours [a]o = +9°. 

An interesting possible application in our society is in super absorbers, which are currently made with polyacrylates, but these suffer from poor biodegradability. Since the demand for short-use super absorbers is growing, a product with a short lifetime and therefore a quick and safe disposal is required. Carboxylated starch can be such a product, but first, an efficient method to oxidize starch needs to be developed. Currently used methods produce stoichiometric amounts of waste products, so the search for a catalytic process is ongoing. 

Starch for use in papermaking has to meet specific purity requirements in residual oil, protein, bran and ash content. Industrial starches have a protein content (N X 6.25), ranging from about 0.05% for potato starch to 0.3-0.6% for com starch, depending on separation efficiency during production. Excess protein content will induce foaming in dispersions of starch and affect the quality and strength of the coated surface. Starch for use in the paper industry should not contain more than 0.4% protein. Oxidized starches tend to have the lowest protein content. Residual oil will cause retrogradation due to complex formation with amylose. 

Dextrins (pyrodextrins) are made by heating dry starch with or without acid. Since it is a dry process, recovery of water-soluble materials is simpler than with aqueous fluidity and oxidized starches. Depending on reaction conditions, greater or lesser amounts of three reactions will occur (a) hydrolysis (b) transglycosidation and (c) repolymerization. According to which predominates, the product is a white dextrin, a yellow dextrin or a British gum. Like other converted materials, these products offer a way to use higher solids to increase performance. 

Oxidation with chlorine or sodium hypochlorite reduces the tendency of amylose to associate or retrograde. Oxidized starches are used where intermediate viscosity and soft gels are desired, and where the instability of acid-converted starches is unacceptable.76 Oxidized starches are reported to give batters improved adhesion to meat products and are widely used in breaded foods.76 Fuller77 reported that candies made with hypochlorite-oxidized starches gel and dry faster and have increased clarity, longer shelf life and better taste than those made with acid-thinned counterparts. 

Oxidized starch loses its ability to gel, thereby making low Tfi dispersions. Glucose dialdehyde is a glucose oxidation compound used to crosslink agarose (linear) and dextran (branched) for their performance as adsorbents. Oxidized celluloses are a substitute for glues manufactured from animal by-products. 

Application of Oxidized Starch-Containing Reagents (OSR) as Binding Agents in Production of Resin-Bonded Chipboard and Cane Fiber Board... 

Oxidized starch-containing raw materials obtained from both starch and starch-containing raw materials (for example from affected amaize corns) may be used as ecologically pure bonding agents in production of resin-bonded chipboard and cane fiber board [9, 10],... 

Some beer bottle manufacturers have added poly(vinyl alcohol) to the adhesive to ensure resistance to iced water yet retain washability in the bottling operation. Others have used the starch paste to extend the more water-resistant casein adhesives (0). Newer adhesives are being developed based on double treatments of starches such as hydroxyalkyl ethers of oxidized starch, blending these products with other specified polymers (12,13) or adding synthetic resins... 

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