Properties of Starches

Starch occurs as a white powder which is insoluble in cold water but forms a colloidal solution after boiling with about 15 times its weight of water. The solutions form a translucent jelly on cooling. When starches are heated with water, the 

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STMP reacts with other nucleophiles such as aqueous ammonia to yield amidophosphates, which contains a P—N bond. STMP is used for the modification of the physical properties of starch and proteins by reaction with the amino and hydroxyl groups. 

A. and Angel O. Z. (2008). Synthesis and spectral properties of starch capped CdS nanoparticles in aqueous solution J. Cryst. Growth, 310,160-164. 

There are five prime factors that determine the properties of starches 1. starch is a polymer of glucose (dextrose) 2. the starch polymer is of two types linear and branched 3 the linear polymeric molecules can associate with each other giving insolubility in water 4. the polymeric molecules are organized and packed into granules which are insoluble in water and 5 disruption of the granule structure is required to render the starch polymer dispersible in water. The modification of starch takes into account these factors. 

The structure and properties of starch have formed the subject of very extensive investigations. As a result, the main structural features and the highly polymeric nature of the molecule are now well established, and starch is known to consist of chains of D-glucopyranose units joined in the main by 4 —> 1-a-D-glycosidic linkages. 

One of the important properties of starch is that it undergoes gelatinisation. Starch is insoluble in cold water and intact starch granules do not absorb cold water. However, it is possible to prepare a dispersion of... 

Retrogradation is another important property of starch. It is generally accepted that retrogradation is involved in the staling of baked products such as bread. In particular it appears that retrogradation is the recrystallisation of the amylopectin present. Notably, retrogradation is still a subject of research. The application of techniques such as 13C NMR allows insights that older techniques do not provide. 

Jane, J., Chen, Y. Y., Lee, L. F., McPherson, A. E., Wong, K. S., Radosavljevic, M., and Kasemsuwan, T. (1999). Effects of amylopectin branch chain length and amylose content on gelatinization and pasting properties of starch. Cereal Chem. 76, 629-637. 

Stevens, D. J. and Elton, G. A. H. (1977). Thermal properties of starch/water system. Part I. Measurement of heat of gelatinization by differential scanning calorimetry. Die Starke 23, 8-11. 

Tomita, Y., Sugimoto, Y., Sakamoto, S., and Fuwa, H. (1981). Some properties of starches of grain amaranths and several millets. /. Nutr. Sci. Vitaminol. 27, 471-484. 

Zobel, H. F. (1984). Gelatinization of starch and mechanical properties of starch pastes. In "Starch Chemistry and Technology" (R. L. Whistler, J. N. BeMiller, and E. Paschall, eds.), pp. 285-309. Academic Press, Orlando, FL. 

At this point little is known about the interrelationships between composition, structure, starch-degradation and physical disintegration properties of starch-plastic composites. Continued work towards development of a laboratory assay for biodegradability will eventually result in the establishment of a sufficient database to elucidate these relationships, allowing development of a host of starch-containing plastic products for both existing and new markets. 

Table 16 Surface properties of starches modified by octadienyl groups...

Aberle, T., Burchard, W., Vorwerg, W., Radosta, S. (1994). Conformational contributions of amylose and amylopectin to the structural properties of starches from various sources. Starch/Stdrke, 46, 329-335. 

Kozlov, S. S., Blennow, A., Krivandin, A. V., Yuryev, V. P. (2007). Structural and thermodynamic properties of starches extracted from GBSS and GWD suppressed potato lines. Int J. Biol Macromol, 40,449 60. 

Viks0-Nielsen, A., Blennow, A., Kristensen, K. H., Jensen, A., Moller, B. L. (2001). Structural, physicochemical, and pasting properties of starches from potato plants with repressed ri-gene. Biomacromolecules, 3, 836-841. 

Yusuph, M., Tester, R. F., Ansell, R., Snape, C. E. (2003). Composition and properties of starches extracted from tubers of different potato varieties grown under the same environmental conditions. Food Chem., 82,283-289. Zhu, Q., Bertoft, E. (1996). Composition and structural analysis of alpha-dextrins from potato amylopectin. Carbohydr. Res., 288, 155-174. 

It is generally accepted that each hydrocolloid affects the pasting and rheological properties of starch-based systems, like mashed potato, in a different way (Chaisawang and Suphantharika,... 

An understanding of physicochemical and structural properties of starch will offer the possibility to control the quality of potato and potato products (e.g. digestibility), and to produce new potato starches with added value. As a result, it is critical to understand and apply advanced analytical techniques to characterize and evaluate the quality of potatoes and potato starch. In this chapter, the advanced analytical techniques to evaluate the quality of potatoes and potato starch are introduced and discussed in detail. 

Potato starch usually contains 0.01-0.6% (w/w) phosphorus. Although phosphorus is present at very low levels, it has a significant effect on the physicochemical properties of starch. Phosphorus is in part responsible for the high swelling power, paste stability, and resistance to enzyme hydrolysis of potato starch. Potato starches contain significant amounts of monophosphate esters... 

Liu, Q. (1997). Charaeterization of physieo-ehemioal properties of starch from various potatoes and other sources. Ph.D. Thesis, Laval University, Quebec, Canada. 

Liu, Q., Weber, E., Currie, V., Yada, R. (2003). Physicochemical properties of starches during potato growth. Carbohydrate Polymers, 51(2), 213-221. 

Briant, A. M., Personius, C. J., Grawemeyer- Cassel, E. (1945). Physical properties of starches from potatoes of different eulinary quality. Food Res., 10,437 144. 

Table 10.2 Physico-chemical properties of starches from different botanical sources... 

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