The purpose of the article. During developing technological processes for the production of grain smoothies, it is necessary to determine how the organoleptic and related structural and mechanical properties change during storage using structure-forming agent. The smoothie structure undergoes changes over time that can be positive or negative. These changes can be analyzed and predicted using the basic structural and mechanical parameters. Research methods. The aim of the study is to determine the influence of structure formers on the rheological properties of grain smoothies during storage. The methodological basis of the study is an integrated approach, both in the formulation of tasks and in the conduct and analysis of research results using new theoretical developments, modern computer methods of mathematical modeling and analysis. Scientific novelty. There are two main periods of change in the characteristics of the smoothie structure. During the first 15 days storage period all the structural and mechanical properties of the smoothie remain unchanged. So, the rate of structure destruction is m = 0.61, the plastic viscosity is ηпл = 7.71 Pa·s, the effective viscosity at a unit shear rate is B0 = 292 Pa·s, yield point is σ0 = 240 Pa, the Bingham yield point is σд = 832 Pa. From sixteen storage days the value of all the basic structural and mechanical characteristics of the smoothie begins to grow up. During storage for 30 days the rate of rate of structure destruction m increased from 0.61 to 0.69. Such an increase characterizes the strengthening of the anomalous, non-newtonian properties of the smoothie. The plastic viscosity η пл increased by 12.1%, the effective viscosity at a yield point B0 increased by 29.5%. Conclusions. The study of the structural and mechanical properties of the smoothie lasted 30 days. At the end of this period, the smoothie acquired a condensation-crystallization structure. The yield strength was reached 2200 Pa. Thus, the recommended storage period of a smoothie is 15 ± 0.5 days.