Influence of Water-Soluble Nonionic Emulsifier on the Rheology of Heat-Set Protein-Stabilized Emulsion Gels

Abstract

The influence of nonionic emulsifier Tween 20 [polyoxyethylene (20) sorbitan monolauratel on the small-deformation shear rheological behavior of j3-lactoglobulin emulsion gels has been investigated. Measurements are reported for heat-set oil-in-water emulsion gels (5-10 wt % protein, 38 wt % oil, pH 7) containing surfactant added afier homogenization but prior to heat treatment (30 min at 90 "C). Storage and loss moduli (frequency 1 Hz) and protein surface coverages of emulsion gels containing 6,7, and 8 wt % protein have been determined at 30 "C. Comparison with results from the equivalent rheological experiments on pure j34actoglobulin systems (12-14 wt %, pH 7) shows that the incorporation of fine emulsion droplets greatly reduces the overall concentration of protein required to make a self-supporting gel. For constant oil content and thermal gelation conditions, the emulsion gel strength is very sensitive to protein content and surfactanffprotein molar ratio R. In particular, the storage modulus has been shown to increase a t low emulsifier contents (R cz l), to decrease a t intermediate emulsifier contents (R PZ 2), and then at high emulsifier contents (R L 4) either to increase again or to remain low depending on the protein content. This behavior can be explained in terms of the effect of system composition on the balance between the different kinds of interfacial and bulk protein-surfactant interactions.

Synergistic stabilization of heat-treated emulsions containing mixtures of milk proteins

“…This suggests that additional flocculation may be taking place on cooling of the emulsions, and that the introduction of caseinate even at this late stage prevents further droplet-droplet association. We note that a somewhat analogous effect occurs when the rigidity of a b-lg-stabilized (emulsion) gel increases strongly on cooling as a result of enhanced hydrogen bonding and disulphide cross-linking (Dickinson & Hong, 1995, 1997.…”

Investigation on the rheological properties of agar gels and their role on aroma release in agar/limonene solid emulsions

“…Most of the data that are available in the recent literature on filled-gels concern heat-set whey protein gels and acid-induced skimmed milk/casein gels (Chen & Dickinson, 1998;Chen, Dickinson, & Edwards, 1999;Dickinson & Hong, 1995;Dickinson, Hong, & Yamamoto, 1996;Van Vliet, 1988;Xiong, Aguilera, & Kinsella, 1991;. Both small and large deformation properties of these materials have been studied.…”

Fat mimetic capacity of Chlorella vulgaris biomass in oil-in-water food emulsions stabilized by pea protein

“…The addition of microalgal biomass to an emulsion system can produce different effects: either stability improvement through the development of cooperative effects with the pea protein or loss of surface viscoelasticity when it induces the displacement of the protein from the interface, as any other emulsion additive (Dickinson & Hong, 1995).…”