In the article the method of synthesis and analysis of physical and chemical properties of film-forming edible gels basing on compositions of uronic polysaccharides cross-linked with calcium nanoparticles. The prospects for the practical use of synthesized compositions on the basis of high-guluronate sodium alginate and low-ester amidated pectin as materials for provision of film-forming edible gels is determined. The interphase boundary in the composite hydrogel is analyzed, which is a transition layer in which the properties change gradually (transition from the properties of phase 1 to the properties of phase 2), while the second phase, with consideration of interphase interactions, is responsible for morphology of film-forming edible gels. The nature of the interactions between the components that is determined to covalent bonds in block-and graft copolymers, forming interpolymer complexes at the expense of appearances of hydrogen bonds, donor/acceptor, ionic and hydrophobic interactions of functional groups, as well as due to engagements of macromolecular chains in interpenetrating and semi-interpenetrating polymer networks. There were studied functions of low-molecular weight polyuronate fractions in binding calcium and calcium-induced gelling of normal low methoxyl pectin (LMP)-the fractions of pectin with two different degrees of esterification (DE), as well as of alginate with two different mannuronate/ guluronate (M/G). It was established that solution on the basis of P:A (pectin/alginate) compositions have properties of non-Newtonian liquids, which viscosity depends on shear stress. It was found that content of nonfilm-forming additives shall be within molecular ratios with consideration of binding points. The water solubility of two-ingredient films and their moisture permeability were determined, and it was shown that the solubility increases in proportion with growth of content of cross-linking agents while growth of moisture permeability is just inconsiderable. The results of the work became the scientific basis for the development of technology of food coatings that self-organize and biodegrade under standard conditions.