2.1. Materials
Sunflower oil was from Saporito foods (Montreal, Quebec, Canada). Inulin was extracted from Jerusalem artichoke by Nutia Food Ingredients (Kentwood, Michigan, USA). Sodium alginate (Landor Trading Company) was purchased from Amazon. Psyllium husk was from a local grocery store (Bulkbarn.ca). Sodium carbonate was from VWR International Co. (Mississauga, ON, CA). Tween 80 (polyoxyethylene-20-sorbitan monooleate) was from Fisher Scientific (CA). Alpha-glucosidase, α–amylase, P-NPG (p-Nitrophenyl-α-D-glucopyranoside), 3,5-Dinitrosalicylic acid and potassium sodium tartrate tetrahydrate were from Sigma-Aldrich (St Louis, MO, USA). Salmon puree, chicken puree, chicken stew puree and beef puree were kindly provided by Apetito HFS Ltd. (Orléans, ON, CA).
2.2. Formulation and preparation of psyllium husk emulsion gels
Psyllium husk (3%) was dissolved completely at 78.4% of water phase (80 ℃) then cooled to room temperature (23 ℃). Emulsions were prepared with 0%, 5%, 10%, 15% and 20% (w/w) inulin to investigate suitable inulin concentration. In preparation, inulin was dissolved in water phase to replace the same amount of water in the formulation. Then 1% sodium alginate and 17.6% sunflower oil were added to the water phase, followed with mechanical stirring using a Tissuemiser (Fisher Scientific, Ontario, CA).