Influence of different calcium-chelating salts on the colloidal structure of skimmed milk under simulated heat treatment conditions

Abstract

Research objective was to study the influence of calcium-chelating salts on colloidal properties of skimmed milk, which best meets the Brazilian regulation for UHT milk production. Citrate and different ortho- and polyphosphate sodium salts were added to milk at 5 concentrations (0.00 up to 0.20% w/w). Samples were heat-treated (oil bath, 155°C, F₀ = 1.43 min), cooled down and analysed. The main changes were caused by tetrasodium diphosphate and sodium triphosphate at 0.15% and 0.20% w/w, as they increased the pH, sequestering capacity and altered the particle size distribution, showing that the impacts on the colloidal structure are influenced by the salt concentration.