Abstract
In this paper we describe the rheological behaviour of Ca2+-induced cold-set gels of whey protein mixtures. Coldset gels are important applications for products with a low thermal stability. In previous work [1], we determined the state diagram for whey protein mixtures that were heated for 10 h at pH 2 at 80°C. Under these conditions, the major whey protein, ß-lactoglobulin (ß-lg), forms fibrils. When whey protein mixtures are heated at protein
concentrations in the liquid solution regime of the state diagram, cold-set gels can be formed by adding Ca2+ ions at pH 7. We studied the rheological behaviour of cold-set gels for various sample compositions for whey protein mixtures. When keeping the total whey protein concentration constant, the elastic modulus, G¿, for the cold-set gels decreased for increasing a-lactalbumin and bovine serum albumin ratios, because less material (blg
fibrils) was available to form a gel network. In the cold-set gels the interactions between the ß-lg fibrils induced by the calcium ions are dominant. The ß-lg fibrils are forming the cold-set gel network and therefore determine the gel strength. a-Lactalbumin and bovine serum albumin are not incorporated in the stress-bearing structure of the gels
Original language | English |
---|---|
Pages (from-to) | 258-264 |
Journal | Applied Rheology |
Volume | 16 |
Issue number | 5 |
DOIs | |
Publication status | Published - 2006 |
Keywords
- heat-denatured whey
- beta-lactoglobulin gels
- globular-proteins
- ph
- aggregation
- percolation