FOOD. Science. Technology. Quality

Food. SCIENCE. Technology. Quality

Food. Science. TECHNOLOGY. Quality

Food. Science. Technology. QUALITY

Authors

J. KOROLCZUK, V. BRETON-DOLLET, J.P. TISSIER, J.F. MAINGONNAT

Title

Rheological properties and microstructure of maize starch / milk proteins gels

Abstract

Maize starch pastes whether containing milk proteins or not behave as shear thinning bodies. The increase in the heating temperature from 100 to 130°C provoked an important decrease in the maize paste viscosity measured at 60°C. The addition of milk proteins greatly changed the effect of heating temperature. A maximum viscosity at 60°C was observed for those pastes heated at 105-115°C for the milk protein concentrate, while for the sodium caseinate it was lowest at 110°C, whereas for the whey protein concentrate, the paste viscosity at 60°C was found to increase during heating. The maize starch gels revealed two types of structure. In the maize starch gels some regions were composed of spherical particles, others of branched and flat filaments of several μm of length and 0.1 to 0.2 μm thick. The microstructure of mixed gels revealed an independent network for whey and starch fractions. These gels showed intermeshing networks, where each polymer developed its own network and no copolymer structure could be perceived. Sodium caseinate/starch solutions failed to form a continuous network and the gel presented multiple fractures.

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