P. Manoj et al., SEQUENCE-DEPENDENT KINETIC TRAPPING OF BIPHASIC STRUCTURES IN MALTODEXTRIN-WHEY PROTEIN GELS, Carbohydrate polymers, 32(2), 1997, pp. 141-153
The structural properties of maltodextrin in mixtures with native whey
protein have been investigated using dynamic oscillation and a sequen
ce of experimental time-temperature, frequency and strain sweeps. Cool
ing of the binary system results in a gelled maltodextrin matrix surro
unding the liquid whey protein inclusions. Subsequent heating denature
s the protein and the formation of a gelled filler changes the viscoel
astic functions of the mixture dramatically. Modelling of the two dist
inct microstructures shows a clear transition from an isostrain condit
ion with a solid-like maltodextrin matrix to an isostress arrangement
where the protein filler forms the strongest phase. Estimation of the
pattern of solvent partition between the two phases suggests that ther
e is a linear, positive dependence between the relative amount of solv
ent kept in the liquid inclusions of whey protein and its polymer conc
entration. However, gelation of the protein immobilizes the mixed syst
em and prevents, within the experimental timescale, solvent diffusion
into the maltodextrin network, thus creating a constant value for the
relative solvent distribution between the two phases. (C) 1997 Elsevie
r Science Ltd.