Application of sonication and mixing for nanoencapsulation of the cyanobacterium Spirulina platensis in liposomes

Encapsulation in the food industry is a process in which one or more ingredients or additives (core) are coated with an edible capsule. The use of liposomes is among the many forms of encapsulation of food ingredients. It consists of a sort of microscopic lipid vesicles, where due to the lipophilic and hydrophilic portion of its constituents, substances of various natures can be encapsulated, and the hydrophilic substances stay in the aqueous compartment and the lipophilic are inserted or adsorbed on the membrane. The aim of this work was to apply two different treatments, sonication and homogenization, in the encapsulation of a protein source, such as the cyanobacterium Spirulina platensis, formed out by the thin-film hydration method. Liposomes were prepared using purified soybean phosphatidylcholine and sonicated at 60°C for 30 min or homogenized at 10.000 rpm for 15 min. The average size, encapsulation efficiency and particle morphology were determined. The type of process applied did not differ when obtaining nanometric size particles, however, the liposomes subjected to homogenization had increased medium size compared to liposomes that were subjected to sonication. Morphologically, the liposomes were more uniform when subjected to the homogenizer.