FOOD. Science. Technology. Quality

Food. SCIENCE. Technology. Quality

Food. Science. TECHNOLOGY. Quality

Food. Science. Technology. QUALITY

Authors

JUSTYNA CYBULSKA, JOANNA MIERCZYŃSKA, PIOTR PIECZYWEK, MATEUSZ STASIAK, ARTUR ZDUNEK

Title

Effect of divalent metal ions on rheological properties of polysaccharide matrix from apple pomace

Abstract

Pomace produced during the apple juice production is composed mainly of cell wall polysaccharides, which constitute a dietary fibre. Since those compounds can be cross-linked with some divalent metal ions according to an egg-box model, they cause the viscosity of aqueous solutions to significantly increase. The apple pomace analyzed was physically and chemically transformed in order to obtain an MPSN polysaccharide matrix. The objective of the research study was to determine the ability of MPSN polysaccharide matrix to cross-link by means of the divalent metal cations of Ca2+, Mg2+, and Fe2+. On the basis of the increase in the apparent viscosity of the solutions analyzed, it was found that each ion applied had the cross-linking ability; however, the greatest degree of cross-linking was obtained by the Ca2+ and Fe2+ ions. The flow curves of MPSN matrix were described by an Ostwald de Waele’s model. The MPSN solutions with calcium ions added at 12 and 15 mM concentration rates were characterized by the lowest flow behaviour indices and, thus, by the highest pseudoplasticity degree. In all the analyzed samples, a thixotropy phenomenon occurred: in the case of Ca2+ and Fe2, this phenomenon depended on their concentration rate. This fact proves their ability to regenerate structure during relaxation.

Keywords

cell wall polysaccharides, apple pomace, rheological properties, divalent metal ions

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