Viscous high-fat foods such as cream, egg yolk, or mayonnaise are co-extruded with a 3% sodium alginate solution from a syringe into a 50 mM calcium chloride solution. The food sample passes through the inner tube of a double needle assembly while the alginate solution is simultaneously extruded through a mantle surrounding the inner needle. As the sodium alginate solution forms a gel on contact with calcium ions, the food sample becomes encapsulated in the calcium alginate gel formed on the surface of the food sample. The encapsulation procedure may be carried out within a temperature range between 0 C and 25 C. Samples may be prepared for scanning electron microscopy or for transmission electron microscopy by selecting either wide or narrow bore needles, respectively.
Veliky, Ivan A. and Kalab, Miloslav
"Encapsulation of Viscous High-Fat Foods in Calcium Alginate Gel Tubes at Ambient Temperature,"
2, Article 11.
Available at: http://digitalcommons.usu.edu/foodmicrostructure/vol9/iss2/11