Volume 1, Issue 2, 2013
A probability correlation between various transitions and the number of microorganisms at different stages of growth has been analyzed. Comparison of the given parameters with those of the environment (temperature, active acidity, oxidation-reduction potential, etc.) allows defining the influence of each parameter. The obtained results and correlations can be recommended for modeling the growth of microorganisms in different environments, cheese mass being one of them.
The problem of preserving the viability, stability and activity of thermophilic lactic acid bacteria Lactobacillus bulgaricus upon freezing is considered. The effect of different freezing conditions and low-temperature storage on the biochemical and morphological properties and stability of the DNA of L. delbrueckii ssp. bulgaricus has been investigated. Sensory evaluation has been carried out for non-frozen bacterial starter cultures containing L. bulgaricus, and their basic physical and chemical parameters (titratable and active acidity and relative viscosity) have been determined. The influence of low temperature on these parameters has been investigated. The effect of freezing and low-temperature storage on the antagonistic activity of L. delbrueckii ssp. bulgaricus strains has been elucidated. The optimum freezing and storage temperatures for the starters containing L. bulgaricus have been determined.
IDENTIFICATION AND PREVENTION OF THE FORMATION OF MEAT WITH PSE AND DFD PROPERTIES AND QUALITY ASSURANCE FOR MEAT PRODUCTS FROM FEEDSTOCKS EXHIBITING AN ANOMALOUS AUTOLYSIS BEHAVIOR
A method for determining the stress resistance of slaughter animals by measuring the electric conductivity of the Tan-Fu biologically active point has been developed. The possibility of preventing the formation of signs of PSE and DFD properties in meat of stress-sensitive animals through the inclusion of succinic acid and a motherwort extract into their diet has been explored. A method for predicting the quality of meat of slaughter animals while they are alive has been developed. The possibility of using electrochemically activated water for proving consumer properties of meat products from feedstocks exhibiting an anomalous autolysis behavior has been explored.
The existing patented technologies of the production of lactulose were analyzed, and leading producers were defined. Crystalline lactulose was produced via the spray drying of lactulose solutions with various mass fractions of solids. The principal dependences of the finished product output on the drying temperature, the solution flow rate, the air flow rate generated by an aspirator, and the gas spray rate were studied. The results of analyzing the presented dependences allowed us to determine the optimal mass fraction of solids in a solution for spray drying. The results of studying the quantitative parameters of dry lactulose, including hygroscopicity, particle size, moisture content, and finished product solubility index, were presented
The aim of this study was to develop probiotic fermented goat milk. Goat milk was inoculated with single (Bifidobacterium longum and Lactobacillus acidophilus) and mixed cultures containing Bifidobacterium longum and Lactobacillus acidophilus. Goat milk was pasteurized at 95°С for 5 min, cooled to 37±1°С, and inoculated with the required culture before incubation. The combined culture B. longum : L. acidophilus (8 : 1) was used when it had attained a pH 4.5±2 and a titratable acidity 65–70. Goat milk for fermented milk was sterilized at 120°С for 10 min, cooled to 37°С, and inoculated with 8–10% of the bifidobacterium culture, and goat milk was pasteurized at 95°С for 20 min, cooled to 42°С, and inoculated with 3% of the L. acidophilus culture. The cultures were used when they attained pH 4.3 and 4.5 and titratable acidity between 56 and 800T. The developed technology of fermented milks and the characteristics of fermented goat milk were studied. According to the findings, we concluded that fermented goat milk was balanced by the amino acid content and products of high biological value. Fermented goat milk with the expected beneficial health effect is based on a high concentration of probiotic bacteria.
A METHOD FOR PROCESSING OF KERATIN-CONTAINING RAW MATERIAL USING A KERATINASE-PRODUCING MICROORGANISM STREPTOMYCES ORNATUS S 1220
The effect of substrate on mycelium growth, the optimal composition of the culture medium, and the optimal cultivation conditions for Streptomyces ornatus S 1220 have been investigated in the present work. The specific activity of keratinase has been monitored during cultivation and activity variation caused by addition of various salts to the cultivation medium has been analyzed. The results of the optimization study are reported and successful use of the culture studied in the present work in processes performed on an industrial scale is anticipated.
Kinetics of the metabolism of the heterocyclic amino acid histidine exposed to the L-histidine ammonia-lyase enzyme has been investigated and the technology of extraction of histidine biotransformation products (urocanic acid and ammonia) from casein hydrolyzates enabling the subsequent use of these hydrolyzates as a milk protein concentrate for the production of specialized dietary products for the nutrition of histidinemia patients has been developed.
Universal genus-specific primers for comparative analysis of two aligned 16S rRNA gene nucleotide sequences of lactic acid bacteria were constructed. The method to identify lactic acid bacteria and a comprehensive plan for their genus and species identification may be used to characterize isolated strains of the Lactobacillus genus bacteria and in quality control of foodstuffs enriched with Lactobacillus.
INVESTIGATION OF THE BIOTECHNOLOGICAL ACTIVITY OF DIRECT-SET STARTER CULTURES IN STRUCTURED DAIRY PRODUCTS
Galactosidase and proteinase activity of lactic acid bacteria of the DELVO-YOG range has been investigated. Lactic acid bacteria of the DELVO-YOG range have been shown to exhibit maximal galactosidase activity in the presence of the CMC stabilizer Akucell 2785; the activity was minimal when sodium alginate NO4-600 was used as a stabilizer. The proteolytic activity demonstrated by the lactic acid bacteria of the DELVO-YOG range was maximal when sodium pyrophosphate SAPP 28 was used as a stabilizer. Minimal proteolytic activity of lactic acid bacteria of the DELVO-YOG range was registered when CMC 6000-9000 was used as a stabilizer. An increase of galactosidase and proteinase activity concomitant to an increase of the stabilizer content from 0.5 to 1.0 mass. % was demonstrated for all the denominations of lactic acid bacteria of the DELVO-YOG range.
Physicochemical and thermal properties of L-phenylalanine ammonia-lyase preparation were studied. Thermal gravimetric analysis of physical and chemical phenomena occurring in the enzyme upon heating was conducted. Heating curves were registered. Kinetic parameters of the evaporation process were identified. Stability of the enzyme to freezing was verified. Cryoscopic temperature of a concentrated L-phenylalanine ammonia-lyase sample was identi-fied. Chemical (dehydration, dissociation) and physical transformations accompanied by exothermic and endothermic effects were found to occur during freezing. Results of the thermal gravimetric analysis demonstrated feasibility of freeze-drying of L-phenylalanine ammonia-lyase preparation and allowed for determination of the optimum tempera-ture ranges for thermal treatment and prediction of operational parameters of the drying process.
The results of Doctor N.A. Voinov and his colleagues’ research aimed at developing gas–liquid film bioreactors are systematized. Fluid dynamics and heat and mass transfer in a liquid film flowing by gravity down a surface with artificial large-scale roughness have been investigated. Relationships based on the plug flow model are suggested for calculating mass transfer in the working zones of the bioreactor. Ways of raising the productivity of the apparatus and reducing the cost of culturing Candida scottii yeast are considered. Closed-loop gas circuit schemes are suggested for the film bioreactor.
Criteria for evaluation of functional properties of emulsion foods are formulated. Balanced fat bases of emulsion sauces are simulated by using liquid vegetable oils of various fatty acid groups: oleic, linoleic, and linolenic. The optimum ratio of the components of an antioxidant-emulsifying complex is established. The efficiency of the antioxi-dant-emulsifying complex (АEC) for the emulsion sauce technology is experimentally confirmed with the help of sea-buckthorn or red palm oils and lecithin. It is established that the introduction of the АEC into the fatty base of emulsion products promotes the deceleration of oxidation processes in the product. The new emulsion sauce recipes and technology are scientifically justified.
Modern methods of chemical modification of enzymes conferring increased catalytic activity and stability to these molecules have been considered. The advantages of using magnetic nanoparticles for the production of stable im-mobilized enzyme preparations are presented. Chymotrypsin immobilization on Fe3O4 nanoparticles modified with amino groups has been found to result in the incorporation of 88% of the enzyme into the solid phase. The change of the optimal pH and temperature ranges and an increase of stability of the immobilized chymotrypsin relatively to the respective characteristics of the native enzyme have been demonstrated.
The article shows the dynamics of the output of baked goods over the past five years in Russia and in the Siberian Federal District. The main trends in the development of the baking branch of the food industry of Kemerovo oblast are specified. Factors that determine the dynamics of baked goods production in the Kuznetsk Basin are considered. Practices of transfer from administrative bread price regulation to targeted subsidies for the least protected strata are shown. Analytical results of the dynamics and structure of the assortment of bread baked by large and medium-sized bakeries of the oblast are presented. Ways of improving the current efficiency of the baking branch of the food industry of Kemerovo oblast are determined.
Cranberries, lingonberries, blueberries, and food systems based on these berries with different solvents and sugars have been studied. A physicochemical analysis of cranberries, lingonberries, and blueberries has been conducted. Crystalline pectin from cranberries, lingonberries, and blueberries has been isolated to determine the degree of etherification. The gelling ability of the pectic substances has been studied. The effect of different solvents and sugars on the rheological properties of food systems containing pectin has been examined. A comparative estimation of the gelling ability of the pectic substances contained in cranberries, lingonberries, and blueberries and in chitosan and alginate gelling agents has been conducted. The viscous properties have been found to increase in the series: cranberry pectin < lingonberry pectin < blueberry pectin < sodium alginate < chitosan. The complexing ability of pectins with respect to copper and iron ions has been studied and compared to that of casein. Casein exhibits a lower complexing ability with respect to iron ions than pectin. It has been found that the complexing properties of pectin vary with its concentration: the more dilute the solution, the higher the complexing ability of pectin.