Manipulation of Adsorption Behaviour at Liquid Interfaces by Changing Protein–Polysaccharide Electrostatic Interactions - Food Colloids: Self-Assembly and Material Science - page 195

Chapter 13

Manipulation of Adsorption Behaviour at
Liquid Interfaces by Changing Protein-
Polysaccharide Electrostatic Interactions

Renate A. Ganzevles, 1,2,3 Ton van Vliet, 1,3 Martien A. Cohen
Stuart 2 and Harmen H.J. de Jongh 1,4

1 WAGENINGEN CENTRE FOR FOOD SCIENCES, P.O. BOX 557, 6700
AN WAGENINGEN, THE NETHERLANDS
2 LABORATORY OF PHYSICAL CHEMISTRY AND COLLOID
SCIENCE, WAGENINGEN UNIVERSITY, P.O. BOX 8038, 6700 EK
WAGENINGEN, THE NETHERLANDS
3 DEPARTMENT OF AGROTECHNOLOGY AND FOOD SCIENCES,
WAGENINGEN UNIVERSITY,

P.O. BOX 8129, 6700 EV

WAGENINGEN, THE NETHERLANDS
4 TNO QUALITY OF LIFE, P.O. BOX 360, 3700 AJ ZEIST, THE
NETHERLANDS

13.1 Introduction
Protein-polysaccharide interactions have been investigated in a diversity of
contexts such as heparin and blood coagulation, 1 protection of enzymes against
high pressure or high temperature, enzyme-substrate binding, and recovery
and fractionation of milk proteins. A well-known example from the food
industry is the use of pectin to stabilize casein micelles in acidified milk drinks.
Due to electrostatic interaction the negatively charged pectin molecules adsorb
on the casein micelles preventing them from acid-induced aggregation via
electrostatic and steric repulsion. 2-4
On mixing an anionic polysaccharide with a globular protein, four different
interaction regimes can be distinguished, depending on pH, ionic strength and
mixing ratio, as described for mixtures of whey protein + arabic gum by
Weinbreck et al.: 5
(i) At neutral pH, both protein and polysaccharide are net negatively
charged, and therefore co-soluble; but there can be some attractive
interaction between the positively charged groups on the protein and the
negatively charged polysaccharide.

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