2.3. Ultrasound-treated emulsion gel
Ultrasound was applied to prepare emulsion gel with above formulation (section 2.2.) based on the method of Leong et al. (2017) with modification. Husk (1.5 g) was first dissolved completely in 13.7g of water (80 ℃) then cooled to room temperature (23 ℃). Inulin (0, 2.5, 5, 7.5 or 10 g) was mixed in the husk solution by ultrasound at 2 W calorimetric power for ~10-20 seconds. Sunflower oil phase (8.8 g) was then mixed with the aqueous phase by ultrasound at 10 W calorimetric power for ~ 60-120 seconds. The mixture was then remixed with 25 g of alginate solution (0.5 g sodium alginate in 24.5 g water) at 10 W until the emulsion appeared homogenous. The formulated emulsions were stored at 4 ℃ for further analysis.
2.4. Droplet size measurement
Droplet size of emulsion gels were determined by polarized light microscope (Axioplan 2 imaging and Zeiss Axiophot 2 universal microscope, Carl Zeiss Inc., Jena, Germany). The images were taken with a Retiga 1300 camera linked to Northern eclipse software. The dispersed droplet size from the images was analyzed via Image J software.
2.5. Meat sample preparation
Puree samples (salmon, chicken, chicken stew and beef) were stored at least -20 ºC until needed and thawed to room temperature for the experiment. Different puree sample (5% and 10% w/w) were replaced with ultrasonic-treated 3% psyllium husk 0%, 10%, or 20% inulin emulsion gels. Each treatment was mixed homogeneously using a Tissuemiser (Fisher Scientific, Ontario, CA). After each mixing, the resultant puree samples were stored at -20 ºC until analysed.