Static stability of partially crystalline emulsions: Impacts of carrageenan and its blends with xanthan gum and/or guar gum

Abstract

In the present study, four different combinations of gums, including carrageenan (CG), its binary blends with xanthan gum (XG) or guar gum (GG) in equal ratios, and its ternary blends with XG and GG in three equal ratios, were involved into making partially crystalline emulsions (PCEs), respectively. The freshly prepared emulsions were systematically characterized by rheological property, particle size distribution, microscopic morphology, interfacial property, and intermolecular interactions, and their emulsion stabilities were further evaluated using multiple light scattering technique and storage test. All PCEs stabilized by gum blends (CG + XG, CG + GG, and CG + XG + GG) obtained decreased apparent viscosities at 0.01 s−1 (10.12–25.32 Pa·s), particle sizes (3.12–4.06 μm), as well as interfacial protein concentrations (22.60–27.01 mg/m2), which were much lower than those with single CG (35.98 Pa·s, 6.72 μm, and 47.74 mg/m2, respectively). The microscopic morphology showed that blending CG with XG and/or GG contributed to formation of firmer three-dimensional matrix, thereby preventing the aggregation of fat droplets. Inclusion of XG and/or GG also significantly reduced contribution of hydrophobic interactions from 0.72 to 0.24–0.44 mg/mL. Both multiple light scattering and storage test revealed that emulsion instabilities were mainly manifested as a clarification at the bottom and an agglomeration at the top. PCE-CG + XG + GG exhibited superior stability with low creaming index (6.20 %) and viscosity (1180.0 mPa·s) after three months of storage. The research aims to evaluate the effects of CG and its blends with XG and GG on stability of PCEs, and the results potentially provide valuable information for manufacture of stable PCE foods.