Saratov State Agrarian University

Introduction. The efficiency of grain harvesting largely depends on the performance of the combine harvester's cleaning system, particularly the upper sieve extension. This component plays a key role in separating grain from various impurities. Poor cleaning efficiency leads to increased grain losses and reduced product quality. Therefore, studying and improving the operation of the upper sieve extension is an important direction for enhancing the overall efficiency of agricultural machinery. Materials and Methods: The study analyzed the operation of the upper sieve extension from both mechanical and mathematical perspectives. The movement of the grain mixture along the extension, its stratification, and the interactions of particles were investigated. The motion patterns of free grains and unthreshed ears, as well as their interactions with the sieve surface, were examined. Using average operational parameters and empirical coefficients, a mathematical model describing the cleaning process was developed. Results: The model allowed deriving analytical relationships that describe the distribution of free grains and unthreshed ears. In particular, the probabilities of grains being directed to the ear auger or ending up in straw residues were determined. Graphical representations visualized the main patterns of the separation process. Calculations showed that the proportion of free grains and unthreshed ears reaching the ear auger ranged from 9.9% to 13.5%, while losses to straw residues varied from 0.86% to 5.05%. Discussion and Conclusions: The results demonstrate that the effective operation of the upper sieve extension directly influences the performance of the combine harvester’s overall cleaning system. The proposed mathematical model provides a reliable tool for analyzing and optimizing the separation process, reducing grain losses, and improving harvesting quality. Future Research and Implications: Future studies should focus on experimental validation of the model under real field conditions, as well as on optimizing the design and operational parameters of the sieve extension. This will enhance the efficiency of agricultural machinery and contribute to more rational use of resources.

The aim of the present work is to obtain immunofluorescent antibodies based on F(ab)2-fragments. Polyclonal antibodies were isolated from blood serum of rabbits hyperimmunised with anthrax pathogen. Cleavage of the immunoglobulin molecule into separate F (ab)2 and Fc fragments was performed with pepsin. Labelling of antibody variable sites was carried out with fluorescent isothiocyanate (FITC). The results of the studies showed high specific activity of the obtained immunofluorescent antibodies based on F(ab)2-fragments in MFA against anthrax pathogen. Closely related strains of soil spore-forming microorganisms did not cross-react or did so at low concentrations. Testing of the specific activity of FITC-labelled F(ab)2 fragments for the detection of pathogens from environmental samples showed that the drug was active at a working antibody titre of 1:128, while the soil-dwelling spore-forming microbe B. cereus was not detected at any working titre of labelled antibodies. In connection with the above-mentioned, the development and introduction into veterinary practice of new technologies based on the latest achievements in biological science opens the prospect of using them to eliminate cross-reactions in immunochemical methods for the indication of the anthrax pathogen.

The objective of the study is to experimentally validate the feasibility of using regionally selected sorghum grain byproducts. The object of the study was a low-fat, high-protein sorghum cake containing textured sorghum flour. Control sample 1 was a Stolichny cake made from premium wheat flour. Two new types of cakes, Divny and Sortik, were used in the study. The Divny cake recipe used whole-grain sorghum flour, while the Sortik recipe substituted some of this flour with textured sorghum flour in a 90 : 10 ratio. Both new cakes were prepared without the addition of butter, which is typically used in recipes. Based on laboratory testing, the recipe for a cake based on textured sorghum flour was optimized.Research shows that consuming 100 grams of the developed fortified products can provide up to 29 % of the daily protein requirement, 9 % of fat, 19 % of carbohydrates, and 14 % of dietary fiber. Vera sorghum grains and textured sorghum flour can be successfully used in muffin recipes, significantly improving the organoleptic characteristics of the products. Experiments have shown that excluding the fat from the recipe does not affect the quality of the products, but the fat content in such products is reduced by 4–5 times, which facilitates more efficient use of raw materials and makes the products more dietary. This approach to food fortification not only satisfies the body's needs for essential nutrients but also makes the products more nutritious and suitable for healthy eating.

Economic mechanisms of state regulation play a crucial role in creating economic and legal conditions for profitable and rational use of productive agricultural land in conditions of constant intensification and growth of capital intensity of production. The role of the information basis for the implementation of the provisions of the digitalization of the agrarian economy is assigned to certification, aimed at an objective assessment of land as a means of production, an object of real estate and taxation. The substantiation of the fundamental aspects of certification of agricultural lands according to fertility parameters is given, which are: land as the primary object of certification, taken into account in the Unified federal information system for agricultural lands; soil difference, as a spatial object for assessing fertility in the land; standard crop yields on arable land and productivity of natural forage lands, as a quantitative measure of fertility assessment. Using the example of an arable land plot in the Saratov region, the form of the section of the agro-ecological passport "Agro-production characteristics of the soil cover of an agricultural land plot" is proposed, which ensures the certification of agricultural land as an information basis for the implementation of management digitalization mechanisms.

The article presents the results of a study of methods for the identification of genetically modified soybeans using polymerase chain reaction (PCR). The aim of the study was to control the quality of vegetable raw materials - soybeans by PCR. In the course of the work, modern laboratory devices (“Real-time CFX Connect”, “Rotor-Gene 6000”) and specialized reagents “Vet-Factor” were used. The technique included several stages: sampling, DNA isolation, reaction and analysis of the results. It has been experimentally established that the nutrient content in the studied soybean samples has differences. The genetically modified soybeans showed a decrease in protein, fat, fiber, and phosphorus levels by 3.0–12.0% compared with native soybeans. At the same time, the calcium content in GM soybeans is 11% higher. Based on the data obtained, the authors recommend using native soybeans for food production, and GM soybeans mainly for feed production. The conducted studies have confirmed the effectiveness of using the PCR method for the identification of GMOs in plant raw materials. The data obtained can be used to improve the quality control system of agricultural products and ensure food security.