Phosphated starches applications

Starches have been chemically modified to improve their solution and gelling characteristics for food applications. Common modifications involve the cross linking of the starch chains, formation of esters and ethers, and partial depolymerization. Chemical modifications that have been approved in the United States for food use, involve esterification with acetic anhydride, succinic anhydride, mixed acid anhydrides of acetic and adipic acids, and 1-octenylsuccinic anhydride to give low degrees of substitution (d.s.), such as 0.09 [31]. Phosphate starch esters have been prepared by reaction with phosphorus oxychloride, sodium trimetaphosphate, and sodium tripolyphosphate the maximum phosphate d.s. permitted in the US is 0.002. Starch ethers, approved for food use, have been prepared by reaction with propylene oxide to give hydroxypropyl derivatives [31]. 

Nierle, W. (1969). The influence of the manufacturing conditions on the properties of phosphated com starch and their applications. Starch, 21, 13-15. 

Application of ethylene-,4C to plants resulted in only a 2.4% conversion into soluble carbohydrates, 11% into ether-soluble materials, 6.9% into phytol, 31.7% into cellulose and lignin, and 9.6% into soluble protein and non-protein material, mainly phosphates. 9 Treatment of detached fruit (such as apples, bananas, peaches, figs, and pears) with synthetic auxins, especially (2,4,5-trichlorophenoxy) acetic acid, speeded up ripening, as indicated by color, taste, softness, and starch breakdown. 7 Other fruits have been similarly ripened, 8 and the treatments are effective both on climacteric and non-climacteric fruit. 

Other applications of fluidization have been made to such materials as sodium chloride liable salt), soda ash. sodium phosphate, sodium sulfate, starch, talc, magnesium oxide, dry clay, bone acid, hydrated lime, and various high polymers in powdered or head" form. Fluidization is especially effective in loading and unloading materials from railroad cars and trucks, as well as in moving them aboul within the plant. 

Anionic starches are obtained by reaction with phosphoric acid and alkali metal phosphates or by derivatization with carboxymethyl groups.30,31 This modification is primarily used to introduce amphoteric properties into cationic com starch for application on the wet end of the paper machine. Anionic starches with carboxymethyl substitution are used as thickeners in coating colors or as binders in coatings for specialty paper grades. Oxidized starches are inherently anionic but without thickening action. Potato starch already carries sufficient natural anionic charge to provide amphoteric properties after cationization.32... 

For mechanical stability against hydration and swelling, starch is chemically crosslinked (by adipic acid-acetic anhydride, phosphate, etc.) below Tgz, so that the physical integrity of the granules is not impaired by gelatinization. Weakly crosslinked starches (DS < 0.1) are acid-stable and thus find occasional application in recipes containing vinegar. The many industrial functions of crosslinked starch include use as an adhesive. 

Although TA from yeast is commercially available, it has rarely been used in organic synthesis applications, and no detailed study of substrate specificity has yet been performed. This is presumably due to high enzyme cost and also since the reaction equilibrium is near unity, resulting in the formation of a 50 50 mixture of products. In addition the stereochemistry accessible by TA catalysis matches that of FruA DHAP-dependent aldolase and the latter is a more convenient system to work with. In one application, TA was used in the synthesis D-fructose from starch.113 The aldol moiety was transferred from Fru 6-P to D-glyceraldehyde in the final step of this multi-enzyme synthesis of D-fructose (Scheme 5.60). This process was developed because the authors could not identify a phosphatase that was specific for fructose 6-phosphate and TA offered an elegant method to bypass the need for phosphatase treatment. 

Lack of the amine group "NH2 makes chitin almost chemically inactive. In addition, the availability of chitin as the second most abundant material after cellulose allows its use as an excipient in processing solid drug dosage forms. This facilitates its use with other common excipients, namely microcrystalline cellulose (MCC), lactose, starch, and calcium hydrogen phosphate. Consequently, this monograph will focus on chitin applications as a solid dosage form excipient. 

Amylose triacetate prepared from butanol-precipitated starch may be plasticized with almost any of the common plasticizers which are applicable to the plasticization of cellulose triacetate. For example, some suitable plasticizers are dimethyl or diethyl tartrate, tributyl citrate, tributyl phosphate, tricresyl phosphate, polyethylene glycol, and pentaerythritol tetraacetate. Addition of only 10-20% plasticizer is sufficient to give amylose triacetate films a useful and lasting degree of... 

The above descriptions show the monomeric structures of starch, dextrin, cellulose, and guar gum. In reality, these polysaccharides can be extracted from different sources and the chain length and configuration, molecular weights, and the contents of impurities may vary considerably. Generally, starches have been used mainly as flocculants or flotation depressants for iron oxide minerals and phosphate minerals while the associated silica is floated. Dextrin has been mainly tested as depressants for inherently hydrophobic minerals such as talc, molybdenite, and coal [96]. Applications of polysaccharides in other mineral systems, both in the laboratory and in commercial processes, have also been frequently reported. As can be seen, the polysaccharides have been used or tested as selective depressants in practically all types of mineral systems, ranging from oxides, sulfides, salt-type, and inherently hydrophobic minerals. 

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