be associated with the peptide chain lengths. The
dependence of EAI on the concentration of protein
has been explained by absorption kinetics (Kinsella,
1976). At a low concentration, protein adsorption at
the oil-water interface is diffusion-controlled, while
at high protein concentration the activation energy
barrier does not allow protein migration in diffusiondependent
manner, which leads to the accumulation of
proteins in the aqueous phase (Kinsella, 1976). Thus,
the proteins or peptides were most likely localised in
the aqueous phase, with only a low fraction of them
at the interface. Moreover, an excessive amount of
protein hydrolysate might favor self-aggregation of
long-chain peptides.