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Introduction. The aim of the work was to study the effect of oat β-glucan on the viscosity-speed indicators of mixtures and physicochemical characteristics of milk-vegetable ice cream. Materials and methods. Milk-vegetable ice cream with a mass fraction of fat 3% and oat β-glucan in the amount of 0.5-1.0% with a stabilization system and without, as well as control samples of classic milk ice cream, were prepared. Rotational viscometry and well-known methods for studying the resistance to melting, overrun and ice cream dispersion of the air phase were used. Results and discussion. The structuring ability of β-glucan in ice cream with low fat and dry matter content was studied. The effective viscosity of ice cream mixtures with β-glucan in the amount of 0.5-1.0% is in the range of recommended values. Mixtures of milk ice cream with β-glucan are characterized by thixotropic ability, which is confirmed by the high degree of restoration of the destroyed structure. Combined use of β-glucan and fermented vegetable puree containing soluble pectin and softened vegetable fibers could significantly improve the viscosity-speed indicators of mixtures: the effective viscosity increases by 11.5-15.9%, the degree of recovery in on average - by 10%. Low-fat milk-vegetable ice cream with a β-glucan content of 0-1.0% acquires a creamy consistency. The increase in overrun and resistance to melting of ice cream with β-glucan is due to the formation of a specific secondary foam microstructure that is characterized by the presence of an additional framework of microbubbles, which wraps larger air inclusions and gives them additional mechanical stability during heating. Thus, it was proved that β-glucan is a universal ingredient that can, in addition to enrichment, perform a structuring and stabilizing function in the composition of low-fat milk-vegetable ice cream. Conclusions. Studies prove the feasibility of using oat β-glucan in the amount of 0.75-1.0% in the composition of low-fat milk-vegetable ice cream. [ABSTRACT FROM AUTHOR]

Introduction. The nature of the connection and the characteristics of the process of relaxation of clusters and water domains in milk and protein systems was investigated in order to predict their functional and technological properties. Materials and methods. The relaxation features of water clusters and domains in colloidal solutions of milk proteins were studied by the thermo-stimulated depolarization method (TSD). Electrophoretic analysis of the fractional composition of milk proteins was performed according to modified Laemmli method. Results. The peculiarities of water distribution in bulk protein matrices in milk and in hydrated milk protein concentrates by TSD were studied. On the basis of comparative analysis of TSD spectra of relaxation of dipole structures of water in low-temperature and high-temperature regions in samples of fresh skimmed milk, reconstituted skimmed milk powder and sodium caseinate solution, a significant difference in the nature of water cluster formation in these systems is proved. Milk protein concentrates with reduced energy of activation of depolarization of water in the hydrated state are found to form spatial grids with smaller cell sizes than proteins of natural milk. The revealed effect is explained by the fact that under the influence of heat treatment and drying there are significant conformational changes of protein compounds caused by the denaturation of the majority of serum proteins, in particular, immunoglobulins, serum albumin, ß-lactoglobulin and a-lactalbumin. It is relevant to use in composition of foods milk protein concentrates, whose protein matrices have spatial limitations and hold water clusters smaller than that of natural milk. The results of the research are of practical importance as they allow the purposeful formation and stabilization of the spatial structure of protein-containing food systems. Conclusions. The peculiarities of the nature of water bonding in hydrated milk-protein systems of different degrees of heat treatment have been established. [ABSTRACT FROM AUTHOR]