摘要 : We address the issue of the size of the protein aggregates (nano-particles) required to produce depletion flocculation in sodium caseinate-stabilised emulsions of neutral pH. We predict that a casein nano-particle radius of around... 展开 We address the issue of the size of the protein aggregates (nano-particles) required to produce depletion flocculation in sodium caseinate-stabilised emulsions of neutral pH. We predict that a casein nano-particle radius of around 20 nm causes the strongest depletion flocculation of fine emulsion droplets (mean diameter similar to0.4 mum), i.e., corresponding to a size ratio of about 10:1. This optimum size is the result of a compromise between (i) it being small enough to generate a high number density of non-adsorbed nano-particles, and hence a substantial osmotic pressure, and (ii) it being large enough to give a substantial depletion layer thickness. It turns out that the estimated optimum size of casein nano-particles for inducing depletion flocculation is similar to the size of small casein aggregates actually found in sodium caseinate dispersions at low ionic strength. (C) 2004 Elsevier B.V. All rights reserved. 收起