An effective way to increase resistance of the enzymes and microorganisms of sourdoughs for sour milk drinks to the inhibiting factors of the environment is to stabilize them by immobilizing on different carriers (matrices). In the research institute of food technologies and technologies of processing of livestock products of the Bila Tserkva National Agrarian University a technology for manufacturing modified gelatin as a carrier for immobilization enzymes and microbial cells of sour milk yeasts was developed. Considering that this substance is a new food supplement, therefore, it is necessary to conduct its preclinical studies. Along with the immobilization of enzymes, lately, much attention is being paid to immobilization of cells and sub-cell structures. This is justified by the fact that during the use of immobilized cells the need for isolation and purification of enzyme preparations is eliminated, and constant synthesis of cells by its own enzymes allows conducting catalysis processes during a long period of time. In addition, the immobilization of cells on large particles of the matrix makes it easy to separate them at the final stage from the culture fluid without destroying them with the preservation of the asepsis. This makes it possible to use such cells many times and abandon the complex and laborious operations of the previous development of the producer biomass. Immobilization of cells by incorporating into various gels, membranes, fibers is based on chemical and physical interactions. Chemical methods are used less frequently than other methods and are not suitable for the immobilization of living cells. Inclusion of cells in the composition of gels, membranes and fibers are used much more widely. With this method of immobilization cells can maintain viability and in the presence of the nutrient medium to multiply in the surface layers of gels. Immobilized microorganisms are also used in the food industry. The most common practice is brewing and winemaking. A common carrier for the immobilization of enzymes and cells is the native gelatin nutritional supplement, which is obtained by prolonged thermophysical treatment of collagen of skin, bones, cartilages and hoofs. Thus, the purpose of our work was to study the acute toxicity of modified gelatin in white linear mice. Determination of acute toxicity of modified gelatin was carried out under conditions of vivarium of the Bila Tserkva NAU on white mice. During the first experiment, groups of three heads in each were formed. Animals were given a suspension of a dietary supplement, providing its administration with modified gelatin at doses of 5 mg, 50, 100 and 200 mg per kilogram of body weight. During the second experiment, groups were formed six heads in each. Mice were injected with a suspension of modified gelatin for 1000, 2000, 3000, 4000 and 5000 mg / kg of body weight. Investigated suspensions of modified gelatin were injected into the stomach through the oral cavity once (one or two doses over a certain period of time) using a metal probe with a welded tin head. Observations for mice were carried out for 14 days. The degree of toxicity of the food additive was established in accordance with GOST 12.1.007-76. The handling of the material during the determination of acute toxicity of the modified nutritional supplement of gelatin was carried out according to the methods set in the monograph. The experiments were carried out in accordance with the provisions of the European Convention for the Protection of Animals, used in experiments and other scientific purposes (Strasbourg, 1986). As a result of 14 daily monitoring of laboratory mice, it was found that the suspension of modified gelatin in doses ranging from 5 to 200 mg / kg body weight (first experiment) did not cause animal death (DL0). It should be noted that animals did not change their ethological characteristics: the mice moved freely, responded to stimuli, ate food and drank water. There was no disturbance of the functions of the gastrointestinal tract in animals. After administration of modified gelatin suspension at doses ranging from 1000 to 5000 mg / kg body weight, no fatal cases were observed during the observation period. Intra gastric administration of the studied food additive at doses of 1000-4000 mg / kg did not have a negative effect on the behavior of mice. These animals showed no appetite disturbances, no coordination of movement. Clinical signs remained unchanged during the experiment. At doses of modified gelatin, 5000 mg / kg mice refused to eat for some time. However, after 9-10 hours, experimental mice began to eat food. Thus, modified gelatin belongs to low-toxic substances – 4 classes according to GOST12.1.007-76. Its DL50 at intra gastric administration to laboratory animals (white mice) is greater than 5000 mg / kg. Key words: modified gelatin, acute toxicity, white mice, animal death, immobilization of cells, preclinical studies, oral administration of suspension.

Key words: modified gelatin, acute toxicity, white mice, animal death, immobilization of cells, preclinical studies, oral suspension administration.