Liposomes loaded with phenolic extracts of Spirulina LEB-18: Physicochemical characterization and behavior under simulated gastrointestinal conditions

Liposomes composed of rice (RI.,) and soybean (SL) lecithins were produced by reverse phase evaporation and used for the encapsulation of phenolic extracts from Spirulina LEB-18 (S-RL and S-SL for liposomes of rice and soybean lechitin, respectively). Liposomes were characterized in terms of size distribution, polydispersity index, and zeta-potential; the chemical interactions between the phenolic compounds from Spirulina and liposomes were evaluated by Fourier Transform Infrared Spectroscopy (FTIR), and X-ray diffraction (XRD) and differential scanning calorimetry (DSC) were used to evaluate their crystallinity pattern. The release behavior of phenolic extracts was evaluated under two different pH conditions. Afterwards, in vitro digestibility of liposomes was evaluated in a dynamic gastrointestinal system. Liposomes exhibited high encapsulation efficiency (88.28% and 97.35% for S-RL and S-SL, respectively) and sizes ranging between 250 and 291 nm, showing to be good candidates for the encapsulation of phenolic extracts obtained from microalgae. Results showed that liposomes are stable at low pH values and that they are able to resist to the stomach conditions but they lose their integrity under intestinal conditions. This work increases the knowledge about the effects of in vitro gastrointestinal digestion on liposomes and provides important information for the design of liposome formulations aiming their application in pharmaceutical and food applications.