Structural–Functional and Water-holding Studies of Biopolymers in Low Fat Content Spreads

Abstract

Structural and textural properties of edible low-fat spreads were obtained using various formulations of milk proteins, maltodextrins and non-gelling agents (e.g. fibres). Dynamic oscillation measurements and compression tests suggest that buttermilk protein from spray-dried retentates obtained by ultrafiltration, and commercial Cerestar potato maltodextrin are the most efficient gelling agents, with better plastic failure. A dispersed system in such a composition can be referred to as a microheterogeneously phase-separated system with a presence of inhomogeneities within one phase. Network studies establish that protein forms a continuous matrix. It is also supported that a substantial amount of the fat and at least part of the protein are in the dispersed phase in the form of protein–fat aggregates, and any non-aggregated protein is in the continuous aqueous phase. Branched maltodextrins and linear non aggregated fibre inclusions penetrate the continuous protein network and these microheterogeneities may encourage plastic failure. Modification of the homogenisation regime can be employed to develop products with stress–strain relationships in the preferred range of specification and commercial application.