Starch acetylated

Starch acetates [9045-28-7] are made by reaction of starch with acetic anhydride. Starch acetates are used in foods to provide paste clarity and viscosity stabiHty at low temperatures. A waxy maize starch acetate is most commonly used. Waxy maize starch acetates for food use are often cross-linked. Acetylated starches are also widely used in warp sizing of textiles. 

In the transmission electron microscopy (TEM) images, the starch nanoplatelets (SNPs) are believed to aggregate as a result of hydrogen bond interactions due to the surface hydroxyl groups [13] (Fig. lA). Blocking these interactions by relatively large molecular weight molecules obviously improves the individualization of the nanoparticles. The acetylated starch and cellulose nanoparticles (SAcNPs and CelAcNPs) appeared more individualized and monodispersed than their unmodified counterparts with a size of about 50 nm (Fig. IB C). 

E 1103 Invertase E 1105 Lysozyme E 1200 Polydextrose E 1201 Polyvinylpyrrolidone E 1202 Polyvinylpolypyrrolidone E 1404 Oxidised starch E 1410 Monostarch phosphate E 1412 Distarch phosphate E 1413 Phosphated distarch phosphate E 1414 Acetylated distarch phosphate E 1420 Acetylated starch E 1422 Acetylated distarch adipate E 1440 Hydroxy propyl starch E 1442 Hydroxy propyl distarch phosphate E 1450 Starch sodium octenyl succinate E 1451 Acetylated oxidised starch E 1505 Triethyl citrate E 1518 Glyceryl triacetate (triacetin)... 

Heins, D., Kulicke, W. -M., Kauper, P, Thielking, H. (1998). Characterization of acetyl starch by means ofNMR spectroscopy and SEC/MALLS in composition with hydroxyethyl starch. Starch, 50,431 37. 

Lawal, O. S. (2004). Succinyl and acetyl starch derivatives of a hybrid maize physicochemical characteristics and retrogradation properties monitored by differential scanning calorimetry. Carbohydr. Res., 339,2673-2682. 

Sodhi, N. S., Singh, N. (2005). Characteristics of acetylated starches prepared using starches separated from different riee eultivars. J. Food Engg., 70,117-127. 

Acetylated starch 1420 E1420 Acetic anhydride Hydroxypropyl groups <7.0% Acetyl groups <2.5%... 

Acetylated starch is more mechanically stable, has a lower cooking (swelling and gelatinization) temperature, and is less prone to gel than the parent starch. Phosphated starch has the advantages of acetylated starch and the extra advantage, in some instances, of high viscosity. The carboxyl-... 

Starch has been acetylated by Barnett s mixture, W hich is composed of acetic acid, acetic anhydride, and a catalyst consisting of equal parts of sulfur dioxide and chlorine. This mixture, originally developed for cellulose esterification," readily acetylates starch at 55 , the acetyl content reaching the theoretical value of 44.8% in about four hours. A critical evaluation of the reaction by Hassid and Dore, and particularly by Higginbotham and Richardson, has shown that the acetates prepared have the viscosity, reducing power, and solubility characteristics indicative of a partially degraded starch. 

Sulfuryl chloride and magnesium perchlorate have been suggested as acetylation catalysts for starch. Sulfur dioxide in acetic acid/ sulfur trioxide in acetic anhydride, and sulfonated fatty acid or sulfonated salicylic acid in a mixture of acetic anhydride and acetic acid have also been reported to acetylate starch. 

Jarowenko W (1986) Acetylated starch and miscellaneous organic esters. In Wurzburg OB (ed) Modified starches properties and uses. CRC Press, Boca Raton, FL, p 55... 

Acetylation of starch, which is commonly done with acetic anhydride and can reach a D.S. between 2 and 3. Highly acetylated starches are soluble in organic solvents and become insoluble in water. They are used for their capability to form films and coatings. 

Acetylated adipate- and glycerol-crosslinked starch, administered at 62% in a cooked diet, was safe to experimental rats.2115 Such esters, as well as acetylated starch phosphates, influenced mineral metabolism to a certain extent in rats, but... 

FRI 96] Fringant C., Desbreres J., Rinaudo M., Physical properties of acetylated starch-based materials relation with their molecular characteristics . Polymer, vol. 37, no. 13, pp. 2663-2673,1996. 

The plasma volume expanders are the substances that are transfused to maintain fluid volume of the blood in event of great necessity, supplemental to the use of whole blood and plasma. Some starch derivatives like hydroxyethyl starch and acetyl starch, which are a group of coUoids, are used to provide sustained intravascular volume expansion. Hydroxyethyl starches are high-polymeric compounds obtained via hydrolysis and subsequent hydroxyl ethylation of glucose units substituted at carbon number 2, 3, and 6 of starch. Recently some waxy starches were also evaluated for plasma volume expander, but more research is needed to establish them as a good substitute for the synthetic polymers. 

Behne, M. Thomas, H. Bremerich, D.H. Lischke, V. Asskali, F. Forster, H. The pharmacokinetics of acetyl starch as a plasma volume expander in patients undergoing elective surgery. Anesth. Analg. 1998, 86 (4), 856-860. 

Derivatized starches are obtained by reaction with a-chloroacids, epoxy derivatives or anhydrides in alkaline conditions. In general, they have lower gelatinization temperature, better film-forming properties and tend to give softer gels. Typical products used in oil drilling fluids, adhesives and paper applications are carboxymethylated starches, hydroxypropylated starches, cationized starches and acetylated starches. 

It is well known that the nucleophilic displacement reactions at tosylated polysaccharides are limited or at least mainly directed towards the primary positions . Therefore, our interest was focused on 6-0-tosyl starch samples with DStos 1- One suitable synthesis path is the protection of 0-2 and the subsequent tosylation. A useful protecting group may be the acetyl ester function. It was recently found that in contrast to conventional esterification processes of starch with acetic anhydride, which leads to a statistic distribution of the ester groups, an acetylation of starch dissolved in DMSO with acetic acid vinyl ester in the presence of sodium chloride yields 2-0-acetyl starch of varying DSac from 0.1 to 1.0. The functionalisation patterns of these new starch products were unambiguously proved by means of various NMR measurements including two dimensional methods . 

However, up to now no subsequent modification of the 2-0-acetyl starch is known. We have found that the 2-0-acetyl starch samples are not soluble in common organic solvents but they swell to a certain extend. Heterogeneous conversions of 2-0-acetyl starch swollen in DMA with Tos-C1/N(C2Hs)3 leads to a small DSt< only (Tab. 3). On the other hand, 2-0-acetyl starch can be dissolved in DMA in combination with LiCl which is an appropriate reaction medium for tosylation as discussed for unmodified starch in detail above. As shown in Tab. 3, the homogeneous procedure in DMA/LiCl is suitable to prepare products of high DStos- At a molar ratio Tos-Cl modified AGU of 2 1 respectively 5 1 using a 2-0-acetyl starch with DSac = 0.7 a DSto of 0.53 respectively 1.37 is reached. From C-NMR )ectroscopy a preferred tosylation of 0-6 can be concluded. 

Table 3. Tosylation of 2-O-acetyl starch with Tos-Cl and triethylamine as a base...

Acetylated starch. See Starch acetate Acetylated sucrose distearate CAS 121684-92-2... 

INS1420 E1420 Synonyms Acetylated starch Classification Food starch modified Definition Starch esterified with acetic anhydride or vinyl acetate... 

High DS starch acetates are used to create brittle films and molded products. These have had little application, due to the economic superiority of cellulose acetates. In general, specific gravity and melting temperature both decrease with an increase in acetylation (45). Highly acetylated starches above 15% acetyl content (DS approximately 0.7) are soluble in water at 50° to 100°C and insoluble in organic solvents. When the acetyl content reaches 40% (DS approximately 2.5), the derivatized starch is soluble in aromatic hydrocarbons, ketones, and glycol ethers. 

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