Rheological methods to analyze the thermal aggregation of calcium enriched milks

MEZA, BARBARA ERICA; OLIVARES, MARÍA LAURA; ZORRILLA, SUSANA ELIZABETH

INTERNATIONAL DAIRY JOURNAL

ELSEVIER SCI LTD

Lugar: Amsterdam; Año: 2019 vol. 97 p. 25 - 30

0958-6946

The colloidal state of calcium enriched milks duringheating and its microstructures were analyzed through the interpretation ofrheometric data with the Brownian aggregation theory, which can be consideredas complementary of the currently used methods. Viscosity was measured at 100 s-1through temperature and time sweeps. It was observed that from 25 to 60°C, viscosityslowly decreased as temperature increased; above 60°C, viscosity sharplyincreased at different temperatures depending on the amount of CaCl2.From time sweeps, the aggregation of casein micelles was described through the Smoluchowskitheory. The addition of CaCl2 at concentrations of 20-30 mmol kg-1decreased the stability factor 5 to 6 orders of magnitude compared tonon-enriched milk. Values of the fractal dimension indicated that aggregationyields disordered aggregates occluding high amounts of solvent. The methodology described may help to analyzethe colloidal stability and the structures when different calcium salts areused for enrichment.