Characterization of surimi particles stabilized novel pickering emulsions: Effect of particles concentration, pH and NaCl levels

Abstract

Pickering emulsions stabilized by biocompatible and edible particles have received increasing attentions recently. The surimi particles were firstly prepared and then the physical characteristics of soybean oil-based emulsions stabilized by surimi particles were investigated. The visual observation of emulsions indicated the emulsified phase volume increased with increasing concentrations (0–4 wt%) of surimi particles. The stability index of sample with 4.0 wt% particles at 0.5 or 0.6 oil fraction (0.5–4.0% or 0.6–4.0%) reached 99.1% and 100% after 14 days storage, respectively. The confocal laser scanning microscopy (CLSM) and cryo-scanning electron microscope (cryo-SEM) observations showed that surimi particles were anchored onto the surface of oil droplets and aggregated to form gel-like network. The droplet size of samples with varied surimi particles at 0.5 oil fraction were found in the range of 76.09–90.38 μm. Additionally, 3.5 wt% surimi particles stabilized samples at 0.5 oil fraction (0.5–3.5%) under a series of pH (3, 5, 7, 9, 11) and NaCl conditions (0.1, 0.2, 0.3, 0.4, 0.5, 0.6 M) showed similar droplet sizes but dissimilar zeta potential. The rheological results suggested the shear thinning and elastic behaviors of emulsions. Increasing either fish protein particles concentration or salt levels could decrease the T23 relaxation time of emulsions. In conclusion, surimi particles can function efficiently as edible Pickering particles to stabilize emulsions.