In this study we have tried to get a more understanding of the structural and thermodynamic basis underlying the ability of the covalent conjugates of sodium caseinate (DMV(the Netherlands) and Sigma) with maltodextrins (Paselli SA-2 and MD-10, AVEBE (the Netherlands) to behave as delivery vehicles for the triggered release of the soy polyunsaturated phosphatidylcholine (Lipoid S100, Lipoid GmbH, Germany) (PC) in the specific place of the gastrointestinal tract. To attain this aim we have studied the consecutive transformations of the structural (Mw, RG, Rh, density, shape/architecture) and thermodynamic (the thermodynamic affinity for the aqueous medium, expressed by the values of the second virial coefficient, A2)) parameters, measured by laser multiangle light scattering, of such delivery vehicles during their digestion in the simulated conditions of the mouth, stomach and intestine under the sequential action of the gastrointestinal enzymes (alpha-amylase, pepsin, trypsin + alpha-chymotrypsin + alpha-amylase) in vitro. The extent of the release of PC from the delivery vehicles, as a result of such successive digestion, was measured too. In addition, the alteration of the phase state of the bilayers in PC liposomes as a result of the complex formation with the conjugates was characterized by the DSC measurements on the model phosphatidylcholine, in particular dipalmitoyl phosphatidylcholine (DPPC). Besides, the impact of the dextrose equivalent, DE, of the maltodextrins (DE = 2 and 10) on the enzymatic transformations of the complexes of PC with the covalent conjugates will be shown and discussed.
PhD, DSc Maria Semenova mariagersem@mail.ru
