Using a model based on the primary structure of  s1 -casein, the colloid stabilising ability of fragmented protein and that of the intact chains are compared. We perform Self Consistent Field (SCF) calculations to obtain the induced interaction potentials between the oil droplets, resulting from the overlap of adsorbed protein layers in each case. For the intact  s1 -casein, we confirm the known result, that the mediated inter-particle interaction potential develops a deep attractive energy minimum at high salt concentrations and pH values close to the isoelectric point of the protein. The same does not occur for the appropriately fragmented systems, with improved emulsion stability predicted as a result, even at pH values close to pI.It is shown that this superior performance, for the case considered, is due to the diblock-type behaviour of one of the fragments. On the other hand, it is well known that  s1 -casein more closely resembles the less favourable triblock structure. However, it is also demonstrated that the presence of a "diblock" like fragment by itself may not always be enough to produce a better emulsion stabiliser. It is seen that the hydrolysis of some peptide bonds may indeed lead to a suitable polypeptide, but that this is displaced from the interface by the structurally less desirable ones, also generated by the fragmentation process. The displacement occurs due to the competitive adsorption between different fragments. The removal of the undesirable fragments from the solution is found to greatly enhance the predicted colloid stabilising ability of the remaining polypeptide.

Many foreseen advances in the design of food structures, suitable for ever demanding nutrient delivery systems, tailored controlled release, microencapsulation and protection of active ingredients, require a generation of superior dispersants than those currently provided by proteins. While the most efficient structure for such dispersants is relatively easy to specify, in foods they cannot simply be synthetically manufactured. The review highlights several possible strategies for realising more efficient food colloid stabilisers and summarises the key recent progress for each approach, both experimentally and theoretically. The emphasis is on those methods that lead to macromolecularly adsorbed layers. Practical aspects apart, we also discuss a number of interesting fundamental questions that each approach raises.

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