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.