Influence of mode parameters of heat treatment on moisture binding capacity of metabiotic food systems

Experimental studies of the effect of the method of inactivating active forms of probiotic microorganisms on the intensity of biosynthesis of exopolysaccharides and the moisture-binding ability of metabiotic food systems were carried out. The object of the research was a consortium of probiotic microorganisms based on Str. thermophiles (B-8328), B. bifidum (АС-1579), B. longum (АС-1257), B. adolescentis (АС-1245), L. acidophilus (В-5097), L. plantarum (В-3962), L. fermentum (В-2875). The inactivation process was carried out in the temperature range of 75-95 0С and a duration of 30-50 minutes. The water- retaining capacity of inactivated biomasses of probiotic microorganisms was studied using a laboratory centrifuge at a rotor speed of 1000-2500 rpm and a duration of 10-50 minutes. The concentration of exopolysaccharides was determined using the phenol-sulfur method. Thermal exposure in test samples lasting 20-50 minutes caused a change in the amount of separated serum in the range of 8-24 % by weight. In a control sample of biomass not subjected to thermal exposure, the same value was 12-32 % by weight and 10-40 minutes, respectively. The data obtained indicate increased functional and technological properties of inactivated biomasses and are due to the presence of microbial exopolysaccharides synthesized by probiotic microorganisms under conditions unfavorable for life. The concentration and absorbance of exopolysaccharides as a result of inactivation of probiotics varied in the range of 74,0-83,0 mcg/ml and 524-542 A, respectively. In the control sample, these values were 31,5-33,5 mcg/ml and 367-380 A. It was found that the most effective inactivation regimen, providing increased synthesis of microbial metabolites, corresponds to the exposure temperature of (75 ± 2) °C, exposure for 50 minutes and subsequent cooling to (4 ± 2) °C.