ANTIMICROBIAL ACTIVITY ASSESSMENT OF FOOD PRESERVATIVES CONTAINING ORGANIC CARBOXYLIC ACIDS

Abstract

Introduction. Microbial spoilage of food products has been a perennial problem. According to the WHO, the world records between 68.4 to 275 million cases of acute infectious diarrhea annually. The microbiological safety of food products is crucial as one of the criteria for their quality. Aim. Antimicrobial activity detection of organic carbonic acids against the most common causative agents of food-borne toxic infections. Materials and methods. The antimicrobial action detection of organic carbonic acids was carried out on bacterial strains S. aureus, S. typhimurium, E. coli, P. vulgaris, C. freundii, K. pneumoniae, P. aeruginosa by the dilution method in tryptone-soy broth and in a buffer solution of sodium chloride with peptone (pH 7.0). The minimum inhibitory concentration (MIC) was determined by the highest value from three determinations for each culture taken in the study. The pH of the medium was determined using a portable pH meter AMT16V (Amtast USA Inc). Results. The growth of all bacterial species, that were used in the study, stopped in tryptone-soy broth with a formic acid content of 0.0625 %, and the concentration of acetic acid for these microorganisms ranged from 0,0625 % to 0,125 %. Propionic and lactic acids inhibited the growth of the vast majority of investigated bacterial species at the same concentration (0,125 %). Citric acid stopped the growth of Salmonella spp. and Klebsiella spp., at a concentration of 0,5 %. Therefore, S. aureus, P. vulgaris, and C. freundii demonstrated the highest level of sensitivity to the action of organic acids. On the other hand, Salmonella spp. were the least sensitive to the acid action, as propionic and lactic acids inactivated them at a concentration of 0,25 %, but citric acid at 0,5 % one. Conclusions. Organic carboxylic acids demonstrate sufficiently high antimicrobial activity and inhibit the growth of bacteria which are the most common causative agents of food-borne infections.