Starch thermal properties

Starch occurs as highly organized structures, known as starch granules. Starch has unique thermal properties and functionality that have permitted its wide use in food products and industrial applications. When heated in water, starch undergoes a transition process, during which the granules break down into a mixture of... 

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. 

Blends of starch and a hydrophobic polymer make it possible to overcome the disadvantages described above. Starch compounds with Ecoflex are used to enhance hydrophobicity as well as the mechanical and thermal properties of compounded products. To obtain high quality film products, the starch has to be treated before being blended with Ecoflex . The crystalline structure of starch granules has to be destroyed because starch granules are as large as the film thickness of typical film applications and would therefore reduce the mechanical properties of the films. 

Table 10.5 Thermal properties during retrogradation of starches from different botanical sources...

Gelatinization and retrogradation (thermal properties) of derivatized potato starch... 

Singh, N., Chawla, D., Singh, J. (2004a). Influence of acetic anhydride on physicochemical, morphological and thermal properties of eorn and potato starch. Food Chem., 86, 601-608. 

Yamin, F. F., Lee, M., Poliak, L. M., White, P. J. (1999). Thermal properties of starch in corn variants isolated after chemical mutagenesis of inbred line B73. Cereal Chem., 76, 175-181. 

Species and/or cultivar differences are also observed in other starch properties and in the properties of isolated amylose and amylopectin. To illustrate, purified amylose samples have been shown to differ in (3-amylolysis limit and average DP.64,67,124 Purified amylopectin samples have also been shown to differ in (3-amylolysis limit, average length of unit chains and viscosity.64,66 67 124,125 Campbell et al.121 observed a range of amylose content from 22.5% to 28.1% in 26 maize inbreds selected for maturity, kernel characteristics and pedigree. Starches from these non-mutant genotypes also differed in thermal properties (DSC), paste viscosities and gel strengths. 

Proteins, lipids and phosphorus are the minor non-carbohydrate components of barley starch. These components have been shown to influence hydration rates, thermal properties, retrogradation characteristics, rhelogical characteristics, susceptibility towards a-amylolysis and processing, and product qualities of starch hydrolysates. 

The addition of various salts to potato starch on its compression up to 1.2 X 109 Pa had only a small effect on the thermal properties of starch, as measured by thermogravimetry/differential thermogravimetry/differential thermal analysis (TG/DTG/DTA). Only FeCl3, CoCl2, and I2 caused significant effects.62... 

Mano JE, Koniarova D, Reis RL. Thermal properties of thermoplastic starch/synthetic polymer blends with potential biomedical apphcabihty. J. Mater. Sci. Mater. Med. 2003 14 127-135. 

Stevens, D.J. Elton, G.A.H. Thermal properties of the starch/water system part 1. Measurement of the heat of gel-atinisation by differential scanning calorimetry. Staerke 40. 1971, 25(1), 8-11. 

Further studies on the decomposition of starch at various temperatures were conducted by Picon. He characterized the composition of gases evolved from pea, wheat, rice, and potato starch, as well as potato amylopec-tin and soluble starch from potatoes, when heated at temperatures fix)m 300 to 1000° (see Table XXIII). It may be seen that there are quite remarkable differences in the pyrolysis of various starches. However, these differences cannot be ascribed solely to the kind, but also to the variety, of plant that produced the starch. The thermal properties of the starch from two different varieties of a given plant differ more than those of starches from two kinds of starch (see Table XXIV). ... 

It was reported that metallation of starch did not change its thermal properties to any significant extent.647,651 655 but also there is report that an increases in thermal resistance of starch can be afforded by derivatizing such starches with metal atoms.666 In every case the reaction products were less susceptible to hydrolysis as compared with unreacted metal salts. 

Since starch is a polymeric glucoside composed of a-1,4- and a-1,6-linked glucopyranosidic units, it was of interest to examine the thermal properties of the linear polymeric fraction of starch, namely, that of amylose. The DTA curves for various amylose fractions, prepared from the same starches, have been reported. Examination of the three fractions reveals three distinct features the endothermic peaks with A7 in of about 150 and 225°C, and a shoulder peak with a A7 in of 3l5°C. There were pronounced exothermic peaks in the 490-51O C temperature range. 

Innocentini-Mei, L. H., Bartoli, J. R Baltieri, R. C., Mechanical and thermal properties of poly(3-hydroxybutyrate) blends with starch and starch derivatives. Macromolecular Symnosia. 1, 77-88 (2003), DOl 10.1002/masy.200350708. 

Jagannath, J.H., Radhika, M., Nanjappa, C., Mtirali, H.S., Bawa, A.S. Antimicrobial, mechanical, barrier, and thermal properties of starch-casein based, Neem (Melia azardirachta) extract containing film. J. Appl. Polym. Sci. 101, 3948-3954 (2006)... 

Bao, M. Sun, D.-X. Zhu, and H. Corke. 2004. Analysis of quantitative trait loci for some starch properties of rice Oryza sativa L.) Thermal properties, gel texture and swelling volume. Journal of Cereal Science 39 379-385. 

Zhang J.F., Sun X., Mechanical and thermal properties of poly (lactic add)/starch blends with dioctyl maleate, J. Appl. Polym. ScL, 94, 2004,1697-1704. 

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