Cold-water-swelling starches

Cold- Water Swelling Starches. Special physical treatment produces starch granules that will sweU in water without heating. Molecular dispersions can be formed by appHcation of shear to the swoUen granules. 

Cold-water swelling starches, 4 722 Cold work, 23 473, 496... 

Features Cold water swelling starch exc. flow props Regulatory FDA 21CFR 172.892... 

Features Cold water swelling starch exc. flow props. 

Syn. Starch Pregelatinized Cold Water Swelling Starches... 

Figure 4-42 Values of Yield Stress of Starch-Xanthan Dispersions Relative to those of the Starch-Water Dispersions (YSA SO) and Relative Mean Granule Diameters (D/DO) Plotted against Values of c[j) of Xanthan Gum waxy maize (WXM), cross-linked waxy maize (CWM), and cold water swelling (CWS).

Achayuthakan et al. (2006) studied vane yield stress of Xanthan gum-stareh dispersions. The intrinsic viscosity of Xanthan gum was determined to be 112.3 dl/g in distilled water at 25°C. In addition, the size of the granules in the dispersions of the studied starches waxy maize (WXM), cross-linked waxy maize (CWM), and cold water swelling (CWS) were determined. The values of yield stress of the starch-xanthan dispersions relative to those of the starch-water dispersions (YSA"S0) and relative mean granule diameters (D/DO) plotted against values of c[ ] of xanthan gum are shown in Figure 4-42. With the values of YS/YSO being less than 1.0, there was no synergism between CLWM starch and xanthan gum. 

Meng, Y. and Rao, M. A. 2005. Rheological and structural properties of cold-water-swelling and heated cross-linked waxy maize starch dispersions prepared in apple juice and water. Carbohydrate Polymers 60 291-300. 

Acylated starch can be copolymerized to yield materials for films, lacquers, and fibers.2111 Starch acetate copolymerized with epichlorohydrin was extruded to give cold-water swelling products with a high degree of friability.2112 Epichlorohydrin-crosslinked starch has been acylated with 2,3-di-O-benzoyl-L-threaric anhydride.2113 The reaction proceeded either in /V,/V-dimethy 11 ormam ide or in toluene, and the non-crosslinked product has also been reported.2114... 

Products known as cold-water-swelling (CWS) starches contain granules that swell extensively in the presence of ambient temperature water. Pqj- their manufaaure... 

Cold water-swelling may be attained by several techniques, but only thermo-mechanical treatment by steam-heated roller-dryers as well as extrusion cooking (- extrusion cooked starches) have gained industrial significance. Dry milling in ball mills or vibratory ball mills are techniques for pilot plant or laboratory use. 

Compared to native starches, monophosphate esters have a decreased gelatinization temperature range and swell in cold water at a DS of 0.07. Starch phosphates have increased paste viscosity and clarity and decreased retrogradation. Their properties are in many ways similar to those of potato starch, which naturally contains phosphate groups. 

Although untreated starches do not swell sufficiently, certain modified forms, such as sodium starch glycolate, do swell in cold water and are better as disintegrants. Various cellulose derivatives, including methylcellulose and carboxymethylcellulose, have been used in this role, but with limited success due to the marked increase in viscosity they produce around the dispersing tablet mass. 

In these plant organs, starch is present in the form of microscopically small granules in special organelles known as amyloplasts. Starch granules are virtually insoluble in cold water, but swell dramatically when the water is heated. Some 15-25% of the starch goes into solution in colloidal form when the mixture is subjected to prolonged boiling. This proportion is called amylose ( soluble starch ). 

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