In vitro digestion of chia and fish oil loaded liposomes prepared with natural lecithins

Abstract

The use of natural phospholipids in liposome formulations has the advantages of being available on a larger scale at relatively lower costs. The effect of natural lecithins obtained from soybeans and sunflowers on the stability and digestibility of liposomes loaded with chia and fish oil was evaluated. Four formulations were studied: C+S (chia oil and soybean lecithin), F+S (fish oil and soybean lecithin), C+SF (chia oil and sunflower lecithin), and F+SF (fish oil and sunflower lecithin). Oil-free controls were included for both lecithins (S and SF). Liposomes stability was analyzed and in vitro digestion was studied in a three-stage (i.e. oral, gastric and intestinal) static model monitoring physicochemical changes (zeta potential, size, confocal microscopy). High stability was found for all formulations. After oral phase, zeta potential had a slight diminution compared to the parent formulations and lower values (abs. values) were obtained for liposomes formulated with S lecithin, regardless of oil type. As for size, S formulations presented the lowest values. Gastric phase destabilized liposome formulations, reducing zeta potential in all cases but chia samples presented lower sizes than fish samples which influenced % FFA liberated in the intestinal phase as more surface was exposed to lipolytic enzymes. As for lecithin type, despite S liposomes presented lower sizes than SF liposomes, SF presented higher bioaccesibilty