Starch Compositions

Through genetic manipulation, com cultivars with altered starch compositions have been developed. Various modified and detivatized starches are... 

A fluid loss additive is described that consists of granular starch composition and fine particulate mica [337]. An application comprises a fracturing fluid containing this additive. A method of fracturing a subterranean formation penetrated by a borehole comprises injecting into the borehole and into contact with the formation, at a rate and pressure sufficient to fracture the formation, a fracturing fluid containing the additive in an amount sufficient to provide fluid loss control. 

Borated starch compositions are useful for controlling the rate of cross-linking of hydratable polymers in aqueous media for use in fracturing fluids. The borated starch compositions are prepared by reacting, in an aqueous medium, starch and a borate source to form a borated starch complex. This complex provides a source of borate ions, which cause crosslinking of hydratable polymers in aqueous media [1552]. Delayed crosslinking takes place at low temperatures. 

T. Sanner, A. P. Kightlinger, and J. R. Davis. Borate-starch compositions for use in oil field and other industrial applications. Patent US 5559082, 1996. 

Raidl and Klein (43) substituted 5, 10, and 15% field pea flour in chemically leavened quick bread. The viscosity of the pea flour batters was significantly lower than either the wheat control or soy containing batters. The starch composition of the pea flour and lower water absorption properties of the protein could have affected the viscosity. Volumes of pea flour loaves were lower than the control and soy loaves. Most of the sensory characteristics of the field pea loaves were similar to those of the control quick breads. However, all flavor scores were significantly lower for pea flour products, since they had a recognizably beany or off-flavor. 

Ma X, Chang PR, Yu J, Wang N (2008) Preparation and properties of biodegradable poly (propylene carbonate)/thermoplastic dried starch composites. Carbohydr Polym 71(2) ... 

Use of unmodified starches in combination with mild acids and carbonates has been claimed.214 Starch moisture content should be no greater than 25%. Acids such as tartaric, citric or malic acids are added at levels between 0.2% and 7%, while the carbonate level is 0.1% to 2%, both based on total starch composition. The acid is stated to serve a two-fold function it depolymerizes the starch during extrusion via hydrolysis, improving expansion at the same time, it liberates carbon dioxide, which acts as a blowing agent, from the carbonate. A typical formula extruded in a twin-screw extruder at 170-195°C yielded a product with a density of approximately 1 lb/ft3 (16kg/m3) and resilience of 60-85%. The foam had a continuous skin with a closed cell structure. 

Genetic modification of many dicotyledoneous crops such as potato using gene transfer via A. tumefaciens is, at present, an efficient and reliable technique the application of the antisense route to limit or neutralize the action of undesirable genes has also been applied successfully to potatoes. Conversely, for monocotyledoneous crops such as maize, wheat, and rice, transformation can be accomplished by the much less efficient particle gun technique. This technique has been improved, resulting in rapid progress in the development of maize and later wheat with improved agronomic properties and/or altered starch composition. 

The information provided in this chapter is limited not only by matters of space and relevance, but also by an additional reason. A number of biotechnological companies and institutions are working in the development of new cultivars with altered starch compositions. Research done by, or on behalf of, commercial enterprises generally is not published in refered journals and is kept secret by the companies until applying for a patent. This policy of secrecy clearly slows down the dissemination of scientific information and deprives scientists of the very helpful peer review (affecting negatively the quality of the research). This tendency, unfortunately, is likely to become more dominant. Limited information is sometimes offered in scientific conferences, but hard data are often missing. 

James, M. G., Robertson, D. S and Meyers, A. M. 1995. Characterization of the maize gene sugary 1, a determinant of starch composition in kernels. Plant Cell 7,417-429. 

Van den Koornhuyse, N., Libessart, N., Delrue, B., Zabawinski, C., Decq, A., Iglesias, A., Carton, A., Preiss, J., and Ball, S. 1996. Control of starch composition and structure supply in the monocellular alga Chamydomonas reinhardii. J. BioL Chem. 271, 16281-16287. 

Clausen AE, Bernkop-Schnurch A. Direct compressible poly-methacrylic acid-starch compositions for site-specific drug delivery. J Control Release 2001 75 93-102. 

TABLE 1.4 Starch composition of quinoa, rice, barley (% dry basis)... 

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