Rheological properties of gelatin gels filled with phospholipids vesicles. Dynamic and uniaxial compression measurements

Abstract

The effects of addition of small unilamellar vesicles (SUV) or multilamellar vesicles (MLV) of phosphatidylcholine (PC) on rheological behavior of gelatin gels (approximatively 5% W/W) were studied. Gelation kinetics of pure gelatin gels and gelatin gels containin glipid vesicles as determined by storage modulus (G’) vs. time were quite similar and no difference was observed on G’ after 20h. Apparent Young’s modulus (E ₀) was decreased by 15% when 5 g/l of lipids (either MLV or SUV) were presented in the gel. When the gels were submitted to three successive unaxial deformations (respectively 25%, 55%, and 75%) at a low rate (2 mm/min), a decrease in the force measured at 20% or 50% deformation, as a function of lipid concentration and deformation number was observed when MLV and more specially when SUV were added. Height loss of the gels after two deformations at 25% and 55% was the largest for gels containing SUV, and the smallest for pure gelatin gels.