RESEARCH OF THE BACTERICIDAL PROPERTIES AND TOXICITY OF COMPOSITIONS FOR STONE FRUIT PRESERVATION

Abstract

Damage of stone fruit during storage begins with the development of mycelial fungi on their surface that destroy the shell of a fruit and its anatomical integrity. Therefore, developing new tools for processing stone fruits on the basis of components harmless to people is a topical task of the modern agricultural, phytochemical, and biological industries. Nine compositions from extracts of medicinal plants and 2% of chitosan have been developed. The raw materials used to obtain extracts were: aloe leaves, camomile inflorescences, spruce bark (in the ratios 4:3:2, 5:4:3, 3:1:2, samples 1, 2, 3, respectively); eucalyptus leaves, basil herbs, thyme herbs (in the ratios 1:2:1, 2:4:3, 2:5:2, samples 4, 5, 6, respectively); lemon balm leaves, sage leaves, verbena grass (in the ratios 3:2:1, 4:3:2, 3:1:1, samples 7, 8, 9, respectively). All the compositions have been tested for fungicidal properties against Monilinia laxa and for antimicrobial activity by the sanitary-bacteriological method, and for toxicity by bacteriological methods (the method of direct inoculation on blood agar and the method of diffusion into agar). In all the samples studied, inhibited growth of the culture of the agent causing stone fruit moniliosis has been detected. All nine compositions have revealed antimicrobial action against Bacillus cereus ATCC 107-02, Escherichia coli ATCC-25922, and Candida albicans ATCC-885-653, with the best results in samples 1, 2, 3, 4, 6, 9. In the study of toxicity by direct inoculation on blood agar, samples 1, 2, 6 caused hemolysis of erythrocytes only in the area of application of the sample. Other samples did not show hemolytic activity. The study has shown that samples 3, 4, 9 are safe for humans, they demonstrate fungicidal properties and antimicrobial action against pathogens of stone fruits, which makes it possible to use them as components of chitosan-based film-forming compositions during storage.