Waxy com

Singh, N., Buriak, P., Du, L., Singh, V., and Eckhoff, S.R. 1996. Wet milling characteristics of waxy com hybrids obtained from different planting locations. Starch/Stdrke 48, 335-337. 

Figure 3. Viscosity of sodium and potassium salts of waxy com starch sulfate (DS 0.5)...

Waxy com starch, also known as waxy maize starch, consists of only amylopec-tin molecules, giving this starch different and useful properties (see Chapter 3). This genetic variety of com was discovered in China in the early 1900s, when com plants were transferred from the Americas. The starch stains red with iodine, not blue as ordinary starches do. When the com kernel is cut, the endosperm appears shiny and waxlike, and the com was termed waxy com or waxy maize. However, it contains no wax. 

Normal dent com High-oil com High-amylose com Waxy com... 

Dextrinization of tapioca starch is well-known. The difficulty in dextrinizing corn starch,64 and the relative ease of tapioca starch conversion,65 have been described. The near-absence of lipids, which interfere with the dextrinization process, has given tapioca dextrins an advantage in stability and color because of their ease of manufacture and control. However, the economics of base starch supply have resulted in a significant shift to waxy com starch as a base for industrial dextrins, even though... 

Further improvements in the retention of pigment in the paper and enhanced sheet formation are obtained when amphoteric starches are used. Phosphate groups have to be added to cationic cornstarch to produce amphoteric properties. Cationic potato starch has a natural source of anionic charge due to its phosphate content. In recent years, waxy com starches, which consist entirely of amylopectin, have been modified for use as cationic or amphoteric agents for papermaking and surface sizing. 

Maltodextrins (DE below 20) have compositions that reflect the nature of the starch used. This depends on the amylose/amy-lopectin ratio of the starch. A maltodextrin with DE 12 shows retrogradation in solution, producing cloudiness. A maltodextrin from waxy com at the same DE does not show retrogradation because of the higher level of a-1, 6 branches. As the DE decreases, the differences become more pronounced. A variety of maltodextrins with different functional properties, such as gel formation, can be... 

Waxy com starch contains only amylopec-tin com starch contains both amylopectin and amylose. This results in a different viscosity profile (Figure 8-37). Com starch shows a lower peak viscosity and less breakdown during heating. After cooling, the viscosity continues to increase, probably because the amylose interlinks with the amylopectin. On further storage at 25°C, the slurry sets to a firm gel. Tapioca starch is intermediate between com and waxy com starch (Figure 8-37). This is explained by the... 

Figure 8-36 Viscosity and Granule Appearance in the Viscoamylograph of 5% Suspension in Water of Cross-Bonded Waxy Com. A = 1 cross-bond per 10,000 glucose units, B = 3 cross-bonds, C = 6 cross-bonds, and D = granule appearance. Source Reprinted from L.H. Kruger and R. Murray, Starch Texture, in Rheology and Texture in Food Quality, J.M. deMan, RW. Voisey, V.F. Raspar, and D.W. Stanley, eds., 1976, Aspen Publishers, Inc.

Achayuthakan, R, Suphantharika, M., and Rao, M. A. 2006. Yield stress components of waxy com starch-xanthan mixtures effect of xanthan concentration and different starches. Carbohydr. Polym. 65 469-478. 

Starch acetates are the most easUy prepared of the starch esters. They have served frequently for the characterization of starch fractions, for investigations of starch structure and as intermediates - in the preparation of methylated starch. Although most acetylation work has been done on white potato starch, considerable attention has been given to the acetylation of other starches such as those from com, - - - waxy com, wheat, - - - canna, rice, " horse chestnut and banana. ... 

In general, starch triacetates are soluble in acetic acid and, except perhaps for potato starch triacetate, are soluble in chloroform, 1,1,2-tri-chloroethane, tetrachloroethane, and other halogenated hydrocarbons. High grade starch triacetates do not appear to be soluble in ethyl acetate or alcohol, while some controversy exists as to the extent of their solubility in pyridine and acetone. Waxy com starch triacetate, perhaps due to its smaller molecular weight, is readily soluble in a wide variety of organic solvents. 

Statches ftom different plant sources differ in their amylose/ amylopectin ratio. For example, com starch contains about 27% amylose, potato starch about 22%, and tapioca statch about 17%. In contrast, waxy com statch contains almost entirely amylopectin, with no amylose. These diffetences modify the physical properties of the statches such that the various types may not be interchangeable in a given pharmaceutical application. For example, amylose-rich maize starch has been studied as a potential tablet film-coating ingtedi-... 

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