Kinetic studies of the thermal inactivation of test crop spores are necessary to develop optimal heat treatment regimes for fruit juices. The purpose of the work is to study the dynamics of changes in the thermal stability parameters DT and z depending on changes in the soluble solids content in canned fruit products using the example of certain types of apple juice products with a pH of 3.80. The regularity of thermal inactivation of ascospores of the mesophilic mold Aspergillus fischeri in concentrated apple juice (JAC) with a soluble dry matter (RSV) content of 70%, in restored apple juice with RSV – 11.2%, and in restored apple juice with pulp with RSV – 16% was studied. The parameters of thermal stability were determined by the capillary method at temperatures of 80, 85, 90, and 95 °C. It was experimentally established that the heat resistance of A. fischeri spores in clarified apple juice was DT 95 °С = 0.16 min, and the parameter value z = 6.76 °C, in apple juice with pulp parameters: DT 95 °C = 0.24 min, z – 7.12 °C, in YaKS – DT 95 °C = 0.39 min, and z – 7.8 °C. The dynamics of thermal stability parameters D and z of A. fischeri mold fungus spores (test cultures) versus RSV concentration of juice products was established. The research results showed that with an increase in the concentration of RSV, the thermal stability of spores increases exponentially. The rate of increase in thermal stability decreases with increasing concentration of RSV. Since the concentration of RSV affects the rheological properties of the product (viscosity), this leads to a change in the kinetics of heating in products with convection heat transfer. Therefore, an increase in the concentration of RSV should inevitably lead not only to an increase in the thermal stability of spores of microorganisms, but also to a shift in the region of optimal modes of heat treatment of products toward an increase in the thermal load to ensure regulatory requirements for microbiological safety.

The research results concerning the application of physical methods of plant raw materials influencing - fresh beetroot - to inhibit microorganisms of Salmonella genus were presented in the work. Pathogenic microorganisms of Salmonella genus pose a threat to humans, being causative agents of typhoid fever, paratyphoid fever and other salmonellosis. The use of effective and available physical methods of influence in the fruit and vegetable processing technology allows us to ensure the maximum conservation of physiologically valuable components of the raw material and its safety. Microwave (microwave field) and ultraviolet radiation were chosen as physical methods for research. The sterilizing effect of the microwave field was clearly expressed - the bacteria survival after such a treatment was 2 or more times less than during heat treatment. Treatment with ultraviolet radiation has a bactericidal effect and is characterized by a minimal effect on the plant materials organoleptic properties. A comparative assessment of the effectiveness of the inhibition of the Salmonella test culture on diced fresh beets after treatment with the selected physical methods was carried out during the study. The samples temperature rose up to 43–46 °C under the influence of a microwave field in the selected mode with a power of 400 W, a duration of 40 s, and a flux density of 0.44 W / cm2. Treatment with ultraviolet (UV) radiation in the C-band (wavelength 253.7 nm) was carried out for 15 min with a dose of 50 kJ / m2 with a total power of ultraviolet lamps equal to 60 V. Processing of fresh chopped beets with UV radiation reduced the number of microorganisms by 5 orders of magnitude from the initial amount. Processing in a microwave field allowed to reduce the initial seed contamination of raw materials by 7 orders of magnitude. Sequential processing in a microwave field and subsequent ultraviolet radiation allowed us to reduce the initial beets seedling by 8 orders of magnitude. The combination of processing methods (microwave + UV) showed the effectiveness of their application to reduce pathogenic microflora.

Microbial death kinetics modelling is an integral stage of developing the food thermal sterilisation regimes. At present, a large number of models have been developed. Their properties are usually being accepted as adequate even beyond boundaries of experimental microbiological data zone. The wide range of primary models existence implies the lack of universality of each ones. This paper presents a comparative assessment of linear and nonlinear models of microbial death kinetics during the heat treatment of the Alicyclobacillus acidoterrestris spore form. The research allowed finding that single-phase primary models (as adjustable functions) are statistically acceptable for approximation of the experimental data: linear – the Bigelow’ the Bigelow as modified by Arrhenius and the Whiting-Buchanan models; and nonlinear – the Weibull, the Fermi, the Kamau, the Membre and the Augustin models. The analysis of them established a high degree of variability for extrapolative characteristics and, as a result, a marked empirical character of adjustable functions, i.e. unsatisfactory convergence of results for different models. This is presumably conditioned by the particularity and, in some cases, phenomenology of the functions themselves. Consequently, there is no reason to believe that the heat treatment regimes, developed on the basis of any of these empirical models, are the most effective. This analysis is the first link in arguing the necessity to initiate the research aimed at developing a new methodology for determining the regimes of food thermal sterilisation based on analysis of the fundamental factors such as ones defined spore germination activation and their resistance to external impact.

While processing plant raw materials, it is necessary to observe the balance of effective dose and quality for processed products. The solution to this problem may provide an adequate direction to determine the optimal processing criteria. For define the minimum processing criteria, information database is required, which makes it possible to determine the mechanisms of processing effect appearing. This base is also a key element in the construction of experimental work that allows improving the technology of applying physical methods in the food industry. The present work objective is to study the consistent patterns of pathogenic microorganisms’ inhibition depending on the electron beam energy and the accumulated dose on Salmonella entrica as an example. As the object of research the museum strain of Salmonella entrica subsp. enterica serovar Typhimurium ATSS 140283 cultivated on an artificial model medium was used. The results of the research showed a two-phase nature of the microorganisms’ death kinetics. This work is based on microorganisms’ death kinetics research. The models for the response of two subpopulations stable and unstable for relativistic electron beam processing have been developed. The distribution of the processing hardness with a subpopulation that is unstable to relativistic electron beam processing was established. The need to combine processing by a relativistic electron beam with other types of active exposure to achieve the maximum sterility rate for the entire population of microorganisms has been experimentally established.

Relevance. Carbohydrates are integral components of the cells and tissues of all living organisms of the plant and animal world; they are important components of the plant cell walls, as well as the extracellular matrix of animal and human tissues. The type of monosaccharide composition of polysaccharides determines their biological functions for the organism. However, it is difficult to establish the relationship between the structure of the carbohydrate molecule and its biological function.Methods. In this article, the author provides an overview of methods for identifying the monosaccharide composition of plant polymers by capillary electrophoresis, in order to optimize the sample preparation procedure and the conditions of analysis. A scheme for the stepwise release of polysaccharides from raw materials is given: the isolation of soluble monosaccharides and polysaccharides, the extraction of the pectin fraction, the extraction of cellulose and hemicelluloses, in order to study the composition of each fraction. A procedure for acid hydrolysis of polymers to monosaccharides using oxidizing agents such as sulfuric and trifluoroacetic acid is described. In the final part of the article, three different schemes for the identification of the monosaccharide composition were analyzed, namely, separation of the components under strongly alkaline conditions, preliminary derivatization with 1-phenyl-3-methyl-5-pyrazolone, preliminary preparation of (S) (-) α-methylbenzylamine S-PEA) derivatives.Results or Findings. An analysis of the literature shows that the composition of polysaccharides is widely studied by various methods. At the same time, a number of problems remain associated with the implementation of these methods in terms of sample preparation and identification of all monosaccharides characteristic of the studied raw materials. The method of capillary electrophoresis can solve some of these problems; however, little has been studied. The study of carbohydrates in plant objects begins with the procedure for extracting carbohydrates (polysaccharides and monosaccharides) from the plant matrix, hydrolysis of polysaccharides, and subsequent identification using the CE method. The optimization of this scheme of the CE method for determining the composition of polysaccharides is an urgent scientific task.