Oil emulsion stability in electrolyzed water solutions

Abstract

Metastable electrochemically-activated water solutions possess unique properties that make it possible to modify food emulsions. This comparative analysis featured the stability of model oil-in-water emulsions with anolyte or catholyte as a dispersion medium, as well as the physical and morphometric profile of the emulsion system. The research involved emulsions based on anolyte and catholyte. They consisted of refined sunflower oil, emulsifier (lecithin), and stabilizers, which were represented by sodium alginate, sodium carboxymethylcellulose, pectins, and agar. The study also covered such parameters as aggregative stability, viscosity, morphometry, oil particle size, and zeta potential. Anolyte and catholyte affected the process of separation in the model emulsions. The samples stabilized with alginate and sodium carboxymethylcellulose proved to be the most stable emulsions while agar triggered gelation. The effect of substituting tap water with metastable electrolyzed water solutions depended on the oil proportion in the emulsion. Catholyte destabilized the samples with 20% of oil and liquified gel in the samples stabilized with agar. Anolyte was more aggressive in destabilizing emulsions with 30% of oil. The effective viscosity of these emulsions correlated with the stable phase fraction. The anolytebased samples had low effective viscosity. The opposite results for emulsions with different oil fractions may have been caused by interface changes, i.e., surface tension, adsorption, coalescence, etc. In the emulsions with 46% of oil and animal origin emulsifier, neither anolyte nor catholyte had any significant effect on the aggregative stability of the system. The revealed patterns can be used to control the properties of emulsion products with oil phase ≤ 30%, e.g., low-fat mayonnaises, sauces, emulsion drinks, etc. Metastable electrolyzed water solutions may provide a reagent-free control of properties and patterns of finished or semi-finished foods and biological raw materials.

Keywords

• electrolyzed water
• anolyte
• catholyte
• oil-in-water emulsion
• aggregative stability
• scanning electron microscopy