А new factor effecting gel strength of pectin polysaccharides

Abstract

Pectin polysaccharides obtained from various raw materials have a different component composition and form gels with water, sugar and acid or calcium. In this study, an experimental approach the gelation properties of different pectin samples, varied from different sources, using new methods of hydrolysis and purification. Samples were obtained by hydrolysis of accelerated extraction of pectin and purified by diaultrfiltration, have a high gel strength. The highest gel strength have been found in series of high methoxyl (HM-) pectin samples of apple, peach, orange and low methoxyl (LM-) pectin samples of commercial citrus pectin and apple pectin obtained by new method. It is shown that in addition to the basic parameters (the content of galacturonic acid, degree of esterification, molecular weight and hidrodinamic radius macromolecule) to affect gel strength pectins aggregation of macromolecules, which is determined by the z-average molecular weight. There were observed a clear pattern of the influence of the molecular weight on hydrodynamic parameters for both HM- and LM- pectin samples on the gel strength. It were shown that a high values of molecular weight, intrinsic viscosity, and radius of gyration of pectin samples can significantly increase gel strength, while the value of Mz oppositely influenced the gel strength. As a result, a systematic analysis of this parameter and its relationship to the average molecular weight found that indeed the ratio Mz/Mw for pectin’s is an crucial to assess the quality of pectin at the study of gel strength for pectin polysaccharides.