Jelly and marmalade products are "lyophilic colloids" – lyophilic colloidal-dispersed, ie microheterogeneous (multi- or polyphasic) systems based on high molecular weight compounds (gelatin, pectin, agar, etc.). Therefore, the problem of stabilizing their polyphasic structure is relevant. In addition, the expansion and improvement of the production of jelly and marmalade products requires the search for simplified resource- and energy-saving technology, increasing the stability of the colloidal disperse system, improving the quality and extending the shelf life of finished products. Promising technological applications have food additives in the nanometer range, due to specific and stable physical and chemical parameters, a wide range of functional and technological properties. The paper proposes the solution of the problem of stabilization of the polyphase structure of jelly-marmalade products and the formation of their quality by using the food additive "Magnetofood" (based on double oxide of divalent and trivalent iron: FeO×Fe2O3). "Magnetofood" - highly dispersed powder with a particle size (70–80) nm, which has a fairly diverse functional and technological potential: high ζ-potential and surface activity; clusterophilicity and amphiphilicity; complexing, thickening, structuring, stabilizing, thixotropic properties. This allows us to recommend "Magnetofood" as a food additive of complex action to improve the quality and prolong the shelf life of jelly-marmalade products, in particular jelly-shaped marmalade. The surface-active properties of nanoparticles of the food additive "Magnetofood" are determined: a rather significant value of ζ-potential (34-44) mV, amphiphilicity (marginal wetting angle Q<90o by polar-nonpolar medium) - show signs of stability and stability on polyphasic colloidal-dispersed systems , which increases in acidic environments, in solutions of polysaccharides, proteins on average by (55±)%, which is due to clusterophilicity and self-organization of nanoparticles "Magnetofood" into electrostatic complexes with proteins, polysaccharides and their spatial structuring. It was found that the addition of "Magnetofood" in the mass fraction (0,10–0,20)% to the mass of the structurant increases the viscosity of aqueous solutions of gelling agents in (1,22–1,27) times for agar and in (1,24–1,29) times for pectin and the rate of structuring of gel masses in (1,73±0,01) times for agar and in (1,67±0,01) times for pectin due to the structure-forming action of nanoparticles "Magnetofood". In addition, the ability of the gel structure to thixotropy increases by (1,4–1,5) times and the mechanical strength of the gel well by (1,32–1,80) times for agar and (1,49–1,57) times for pectin due to the stabilizing action of Magnetofood nanoparticles, which allows to reduce the amount of gelling agent by (9.0–11.0)% for agar and by (7.0–9.0)% for pectin.
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