Article ID Journal Published Year Pages File Type
2435600 International Dairy Journal 2008 11 Pages PDF
Abstract

The effects of concentration and molecular structure of barley β-glucans on physical properties of skim milk gels acidified at 42 °C by glucono-δ-lactone (GDL) and reaching a final pH of 4.8 were investigated. Incorporation of β-glucans (0.5–2.0%, w/w) into skim milk aqueous dispersions (10%, 12% and 14%, w/w) resulted in weakening of the protein network upon acidification as shown by reduction of the storage modulus (G′) values of the composite gels, compared with control (free of β-glucan) formulations. However, dynamic rheometry and large deformation measurements (texture profile analysis) revealed that this weakening effect could be reduced or eliminated by using β-glucans with certain molecular features that either promote development of a high viscosity medium (high molecular weight) or formation of a secondary gel network structure (low molecular weight and/or high trimer/tetramer ratio) by the polysaccharide itself. Despite the fact that inclusion of β-glucans at low concentrations increased the levels of spontaneous syneresis, using high β-glucan concentrations or polysaccharide preparations with the aforementioned structural characteristics resulted in milk gels with significantly lower serum separation compared to control formulations.

Related Topics
Life Sciences Agricultural and Biological Sciences Food Science
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