CaO&CaSO4 and CaO&Al2(SO4)3 as Pectin Precipitants–Model of Overlapping Diffuse Layers

  • Tatjana A. Kuljanin University of Novi Sad, Faculty of Technology, BulevarcaraLazara 1, 21000 Novi Sad, Serbia
  • Vladimir S. Filipović University of Novi Sad, Faculty of Technology, BulevarcaraLazara 1, 21000 Novi Sad, Serbia
  • Milica R. Nićetin University of Novi Sad, Faculty of Technology, BulevarcaraLazara 1, 21000 Novi Sad, Serbia
  • Biljana Lj. Lončar University of Novi Sad, Faculty of Technology, BulevarcaraLazara 1, 21000 Novi Sad, Serbia
  • Bojana V. Filipčev University of Novi Sad, Institute for Food Technology, BulevarcaraLazara 1, 21000 Novi Sad, Serbia
  • Lato L. Pezo Institute of General and Physical Chemistry, University of Belgrade, Studentskitrg 12-16, Serbia

Abstract

This work is concerned with the theoretical basis of novel sugar beet juice purification method using binary systems CaO&CaSO4 and CaO&Al2(SO4)3. The Gouy–Chapman–Stern (GCS) model of overlapping of diffuse layers of EDLs on pectin surface and that on Ca2+ and Al3+ ions, theoretically explains this method. The change of the zeta potential was used to quantitatively indicate overlapping of diffuse layers. For the experiment two model solutions of pectin (0.1 % w/w) were prepared, while the concentrations of CaO&CaSO4 and CaO&Al2(SO4)3 in the range of 50–500 g dm-3 were used. The greater decrease in the absolute value of zeta potential indicated greater overlapping of diffuse layers between pectin particles and Ca2+ and Al3+ ions and faster coagulation of pectin. The overlapping degree increased with increased concentration of these binary systems. Pectin with a greater surface charge and multivalent Al3+ from CaO&Al2(SO4), exerted a greater impact on the zeta potential. Optimal quantities of the applied binary mixtures were as follows: 256–640 mg g-1 pectin. This is much lower than CaO commonly used in the conventional process of sugar beet juice purification (about 9 g g-1 pectin).

Keywords: calcium oxide, aluminum and calcium sulfates, pectin, zeta potential
Published online
2018-07-10
How to Cite
Kuljanin, T., Filipović, V., Nićetin, M., Lončar, B., Filipčev, B. and Pezo, L. (2019) “CaO&CaSO4 and CaO&Al2(SO4)3 as Pectin Precipitants–Model of Overlapping Diffuse Layers”, Periodica Polytechnica Chemical Engineering, 63(1), pp. 239-245. doi: https://doi.org/10.3311/PPch.12320.
Section
Articles