Influence of Environmental Stresses on Stability of O/W Emulsions Containing Cationic Droplets Stabilized by SDS−Fish Gelatin Membranes

Abstract

Oil-in-water (O/W) emulsions containing small oil droplets (d32 approximately 0.22 microm) stabilized by sodium dodecyl sulfate (SDS)-fish gelatin (FG) membranes were produced by an electrostatic deposition technique. A primary emulsion containing anionic SDS-coated droplets (zeta approximately -40 mV) was prepared by homogenizing oil and emulsifier solution using a high-pressure valve homogenizer (20 wt % corn oil, 0.46 wt % SDS, 100 mM acetic acid, pH 3.0). A secondary emulsion containing cationic SDS-FG-coated droplets (zeta approximately +30 mV) was formed by diluting the primary emulsion with an aqueous fish gelatin solution (10 wt % corn oil, 0.23 wt % SDS, 100 mM acetic acid, 2.00 wt % fish gelatin, pH 3.0). The stabilities of primary and secondary emulsions with the same oil concentration to thermal processing, ionic strength, and pH were assessed by measuring particle size distribution, zeta potential, microstructure, destabilized oil, and creaming stability. The droplets in secondary emulsions had good stability to droplet aggregation at holding temperatures from 30 to 90 degrees C for 30 min, [NaCl] < or = 100 mM, and pH values from 3 to 8. This study shows that the ability to generate emulsions containing droplets stabilized by multilayer interfacial membranes comprised of two or more types of emulsifiers, rather than a single interfacial layer comprised of one type of emulsifier, may lead to the development of food products with improved stability to environmental stresses.

Layered nanoemulsions as mucoadhesive buccal systems for controlled delivery of oral cancer therapeutics

“…Hence, TPGS mixed emulsifiers can mediate higher Gen-loading capacity and improved drug retention in comparison with single-component emulsifiers, without producing a substantial change of NE ζ-potential, at the final fixed pH of 5.7. In complete agreement with previous data, 27,40 for Chito-layered micro/nanoscale emulsions, the particle electrical charges were found to be inversely dependent on the final adjusted pH value. As pH increased, the cationic charge decreased until neutral or slightly anionic (≈-7.5 mV, at pH 7.0).…”

Evaluation of process parameters in the industrial scale production of fish nuggets

“…On the other hand, lower ash contents (~1.5%) were observed in fresh fish, hence corroborating the influence of the ingredients on the ash content (SURH et al, 2005). Table 2 shows that the experiments that presented lower protein contents led to higher ash contents in the fish nugget (experiments 6, 8, and 10).…”

Multilayer Oil-in-Water Emulsions: Formation, Characteristics and Application as the Carriers for Lipophilic Bioactive Food Components – a Review

“…In some experiments, sodium dodecyl sulfate (SDS) with relatively high hydrophilic-lipophilic balance (HLB = 40) has also been used as a model anionic surfactant. SDS is a non-food-grade emulsifier, but it does represent a number of small-molecule anionic surfactants that are commonly used in foods, can be obtained in high purity and its properties are generally well understood [Stauffer, 2001;Surh et al, 2005;Thanasukarn et al, 2006]. It has been found that surfactant-coated droplets remain highly negative across a wide pH range [Hong & McClements, 2007].…”

“…in commercial oil the iron and copper concentration has been recommended to be < 0.1 ppm and < 0.2 ppm, respectively [Katsuda et al, 2008]. However, it has to be stressed, that the magnitude and range of electrostatic interactions between charged interfacial membranes and transition metals can be reduced as the ionic strength of the solution increases because of the accumulation of counter-ions around the surfaces, which is usually referred to as electrostatic screening [Surh et al, 2005;Guzey & McClements, 2006;Zeeb et al, 2011].…”