The dispersed phase of heterophase model food systems influence on lethality during terminal sterilization

The paper presents the research results of the nature and factors of influence of the dispersed phase of heterophase model food systems (hereinafter FS from the English Food System) on cumulative lethality under various modes of terminal sterilization. To obtain generalized data on the effect of the properties of the dispersed phase of two-component canned products on the lethality values, regardless of the particular properties of these products, experimental studies were carried out on model FS. The dispersed phase of the model FS is styrene acrylonitrile (SAN) balls 8 mm in diameter. Dispersion media FS were chosen according to viscosity: low-viscosity - an aqueous solution of NaCl and sucrose, 1.5 % of each component, medium-viscosity - 11 % aqueous solution of sucrose and clarified apple juice restored with a content of RSV (soluble solids) 11.2 %. The choice of FS is aimed at the authenticity of their properties to the properties of real FS from heterophasic canned products (comotes from small-fruited berries, green peas). Model FS were packed in glass jars with a capacity of 190 ml, hermetically sealed with lids with a fitting for inserting a thermocouple into the jar. Model FS sterilization was simulated in a WCH-16 water thermostat under isothermal conditions with a temperature stabilization error of no more than ± 0.1 °C and subsequent cooling in water. The thermograms of the model FS were recorded by a measuring system including a thermocouple and an eight-channel automatic thermometer connected to a PC for subsequent analysis and approximation of the thermograms. The processed experimental data of studies of the sterilization process made it possible to establish the predominant effect of the dispersed phase on the nature of the heat transfer of heterophase FS, regardless of the rheological parameters of the dispersion medium. Based on the approximation of sterilization and cooling thermograms, it was found that heat transfer in such FSs is predominantly heat conductive. These results make it possible to carry out calculations and mathematical modeling of the process of thermal inactivation of target microorganisms with sufficient accuracy during the final sterilization of real heterophase FS.