Influence of calcium chloride and pH on soluble complex of whey protein‐basil seed gum and xanthan gum

Appropriate pretreatment of proteins and addition of xanthan gum (XG) has the potential to improve the stability of oil-in-water (O/W) emulsions. However, the factors that regulate the enhancement and the mechanism are still not clear, which restricts the realization of improving the emulsion stability by directional design of its structure. Therefore, the effects of whey protein micro-gel particles (WPMPs) and WPMPs-XG complexes on the stability of O/W emulsion were investigated in this article to provide theoretical support. WPMPs with different structures were prepared by pretreatment (controlled high-speed shear treatment of heat-set WPC gels) at pH 3.5–8.5. The impact of initial WPC structure and XG addition on Turbiscan Indexes, mean droplet size and the peroxide values of O/W emulsions was investigated. The results indicate that WPMPs and XG can respectively inhibit droplet coalescence and gravitational separation to improve the physical stability of WPC-stabilized O/W emulsions. The pretreatment significantly enhanced the oxidative stability of WPC-stabilized O/W emulsions. The addition of XG did not necessarily enhance the oxidative stability of O/W emulsions. Whether the oxidative stability of the O/W emulsion with XG is increased or decreased depends on the interface structure of the protein-XG complex. This study has significant implications for the development of novel structures containing lipid phases that are susceptible to oxidation.

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Interactions of WPI and Xanthan in Microstructure and Rheological Properties of Gels and Emulsions

International Journal of Food Engineering ◽

10.2202/1556-3758.1104 ◽

2007 ◽

Vol 3 (4) ◽

Cited By ~ 5

Author(s):

Kooshan Nayebzadeh ◽

Jianshe Chen ◽

SM Mohammad Mousavi

Keyword(s):

Phase Separation ◽

Whey Protein ◽

Viscoelastic Properties ◽

Xanthan Gum ◽

Laser Scanning ◽

Structural Changes ◽

Spherical Shape ◽

Laser Scanning Microscopy ◽

Concentration Addition ◽

Confocal Laser

The effect of addition of xanthan gum (0.05, 0.1, 0.15, 0.25% weight/volume) on the formation and rheology of whey protein isolate (WPI)-xanthan gum gels has been investigated at neutral pH. The elastic modulus (G') values of the gelling test were compared. Low concentration of xanthan added (<0.05%,w/v) has a synergistic effect on the gel strength depend on phase separation, so that whey proteins concentrated in their phase and finally mixed gels with xanthan would be stronger than WPI gels. At higher xanthan concentration (> 0.05%, w/v), antagonist effect was observed by reducing the connection between clusters of whey protein by xanthan, so aggregation disruption and a related decrease in (G'). The phase separation microstructure of WPI-stabilized emulsion containing xanthan gum added has been investigated by rheology and confocal laser scanning microscopy. Xanthan was stained with Fluorescein 5(6)-isothiocyanate (FITC). Low xanthan concentration addition lead to depletion flocculation and increasing the xanthan concentration cause to increase the viscoelasticity of aqueous phase, so retarded macroscopic phase separation over period investigated. Structural changes in emulsion were observed in viscoelastic properties of separated phase in the rheometer. The CLSM image shows different phase which have different viscoelastic properties; xanthan-rich region transforms into the spherical shape which has the lowest interfacial energy and gradually two separated ultimately.

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