PEA STARCH AS THE BASIC MATERIAL FOR PHYSICAL MODIFICATION BY ITERATED SYNERESIS.
 
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Pol. J. Food Nutr. Sci. 2003;53(Special issue 1s):74–78
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ABSTRACT:
In this work pea starch was modified physically acc. to the Polish patent specification P.325981 in which dehydration of pea starch solution by iterated syneresis is a dominating process. The study aimed to recongise how this modification affected the chemical composition, structure, and functional properties of pea starch and provoked formation of a starch fraction resistant to alpha-amylase. It was found that the applied modification procedure caused changes in the crystalline structure from type C to the type B of X-ray diffraction pattern accompanied by a slight increase in the of relative crystallinity. It resulted in an increase in IR band at 1016 cm-1 as well as the differences between relative intensity of some bands in region 1400-400 cm-1. Pea starch modification increased the ability to water sorption change to hydrophilic character, which was revealed by a decrease in the pasting temperature and an increase in viscosity. The retrograded status of both starch macromolecules, amylose and amylopectin, was also confirmed. They interpenetrated and existed as a two-phase system – parts of dense gel fragments disappeared in weak amylopectin-amylose gels. A quantitative decrease in the resistant starch content was accompanied by the change of type acc. to nutritional classification, which could promote the potential biological activity and utilisation. The physical modification process applied in this study can be recommended as a good method for improving the usability of pea starch for food applications.