Stability of oil-in-water emulsion gels with chia (Salvia hispanica L.) mucilage

The purpose of the project was to use olive oil and natural emulsifier chia seeds to make oil-in-water (O/W) emulsions and O/W emulsion gels that do not contain synthetic emulsifiers. To form the mucilages, the chia seed-water ratio was determined as 1:50 and a temperature of 80°C was applied during the 6-hour extraction period. One of the mucilage was prepared by application of ultrasound and then freeze-dried (treated), the other mucilage sample was prepared directly freeze-dried (control). As a result of the freeze drying process, treated mucilage yielded 13.52%, while control mucilage yielded 12.50%. To obtain emulsion systems from treated and control mucilages, emulsions were prepared with mucilage powders at various concentrations (0.25, 0.50, 0.75, and 1.00% w/w). O/W emulsions were prepared at an oil to water ratio of 20:80. Emulsion gels were obtained by applying 95°C heat to another samples prepared in the same proportions as O/W emulsions. There was no clear relationship between ESI and EAI depend on increasing mucilage concentration. In both O/W emulsions and emulsion gels, the creaming index, droplet size, and microscopic image results were consistent. Water holding capacity (WHC) of emulsion gels increased with increasing mucilage concentration whereas oil holding capacity (OHC) decreased. Results indicate that the most stable emulsions were obtained at 1.00% mucilage concentration of emulsion gels prepared in both treated and control mucilages.