Emulsions stabilized by high acyl gellan and KCl

- Effect of KCl addition on emulsions containing high acyl gellan was evaluated.
- Different amounts of KCl could improve stability or cause the breakdown of emulsions.
- KCl-gellan ratio affected the emulsions stabilizing mechanisms.
- Specific KCl amount allowed the formation of physical barrier on droplets interface.

Emulsions containing high acyl gellan (0.025 or 0.100% w/w) as emulsifier/stabilizer with KCl addition (1.6-15,633 mg of KCl/g of gellan) were evaluated. In general a decrease in apparent viscosity and an increase of the droplets size were observed as KCl content rises. Addition of intermediate KCl concentration (62.6-1,563 mg of KCl/g of gellan) could improve the stability to macroscopic phase separation of emulsions with the lower gellan concentration (0.025% w/w). However it was observed that KCl content above a critical value (1,563 mg of KCl/g of gellan) caused the breakup of the emulsions containing 0.025% or 0.10% w/w of gellan, showing that emulsions properties could be easily modulated by the salt-polysaccharide ratio, allowing the formation of emulsions for different purposes. High viscosity of the continuous medium and the repulsive forces of the charged droplets were the main emulsions stabilizing mechanisms. However the formation of a physical barrier on droplets interface by deposition of gellan aggregates could be occurring at particular conditions of KCl-gellan ratio.

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