Determination of stability of food emulsions Part 1. The influence of the type and concentration of protein on creaming stability determined by analytical ultracentrifugation

Abstract

AbstractA centrifugal method is presented for the determination of emulsion stability against creaming (separation of continuous phase). It is based on the centrifugation to final values (equilibrium) for the separated continuous phase and cream. On this methodical basis two indices for the characterization of this kind of stability are obtained, the cream‐ or continuous phase‐quotient. The influence of the type and concentration of protein on the emulsion stability has been investigated with O/W emulsions containing acetylated (AFBPI) and non‐acetylated (FBPI) faba bean protein isolate in a concentration range of 0.1–4 %.The emulsions containing the two types of protein show a clear raise in stability with increasing AFBPI‐ and FBPI‐concentration with the exception of that with 2 % AFBPI at a short storage period of the emulsion.The method is sensitive and indicates small changes in stability during storage, for example. It can be applied to emulsions which show different final values with stepwise increasing centrifugal fields. The method proposed is particularly interesting for preparation and characterization of high concentrated emulsions.