Development of Lactic acid Microorganisms during Fermentation of Substrate with an Increased Concentration of Carbohydrates

Introduction. Creating favorable conditions for the development of lactic acid microorganisms is one of the main factors in obtaining high-quality fermented products. The cycle of their life directly depends on the amount and composition of carbohydrates in plant tissue. Since a significant part of carbohydrates is consumed at the initial stage of fermentation process, additional fortification is needed. The research objective was to study the development rate of lactic acid microorganisms during the fermentation of plant substrate with a modified carbohydrate composition. Study objects and methods. The research featured model medium based on white cabbage of the Parus variety. The medium was fermented with different strains of lactic acid microorganisms: at the first stage of fermentation – Leuconostoc mesenteroides, at the second stage – Lactobacillus casei VKM 536, Lactobacillus plantarum VKM B-578, Lactobacillus brevis VKM B-1309, and their paired consortia. The initial plant material was subjected to grinding and removal of native microflora for the development of target lactic acid microorganisms, then inoculated with L. mesenteroides. The target lactic acid microorganisms were introduced after the first stage of fermentation with simultaneous adjustment of the carbohydrate composition. Results and discussion. The technology included modes of controlled two-stage microbial transformation of plant raw materials using modification of the carbohydrate composition of the substrate. A number of experiments made it possible to select the optimal composition of the consortium and establish the optimal fermentation time at the main stage of microbial processing. When the plant substrate was fermented by the consortium of L. casei + L. plantarum with an increased carbohydrate component, the decrease in the concentration was quite small: after 5–30 days, the decrease in the concentration of microorganisms did not exceed one order of magnitude, which was insignificant at an initial concentration of eight orders of magnitude. In other consortia, the decrease in the concentration of microorganisms was more pronounced. Conclusion. The fortification of the vegetable substrate with carbohydrates made it possible to maintain the concentration of lactic acid microorganisms at a level comparable to the concentration at the time of inoculation. The concentrations of microorganisms varied slightly in both monocultures and their paired consortia during the entire main fermentation stage of the model medium with a modified carbohydrate component. By the end of the main fermentation stage, the concentration of microorganisms did not fall below 107 CFU/g. Therefore, the resulting system “microflora – substrate” proved to have probiotic properties. The study can be used to develop new technological modes of controlled step-by-step fermentation of plant raw materials in order to improve the quality indicators of the final product.

What we should know about the carbohydrate component of infant formula

The article is devoted to the discussion of the carbohydrate component of infant formula for feeding healthy and sick children. The role of glycemic and non-glycemic carbohydrates is shown. In addition to lactose, the following glycemic carbohydrates can be used in infant formulas: maltose, sucrose, glucose, glucose syrup, maltodextrins, pretreated starch and gelatinized starch. Resistant oligosaccharides, nonstarch polysaccharides, and resistant modified starches are also used in child nutrition. The composition and amount of lactose, the main carbohydrate of women’s milk, is discussed. The article presents data on the role of galactose, which is conditionally essential for children in the first months of life due to the rapid growth rate of the infant. Information is presented on the lactose breakdown, the importance of enzymes in the digestion and assimilation processes, the prebiotic effects of lactose, and its effect on the absorption of calcium and other minerals. Advantages of lactose include its low glycemic index, as well as its reduced sweetness, which affects the proper development of taste and low risk of dental caries compared to other fermentable sugars. Specific requirements for the carbohydrate composition of low-lactose and lactose-free formulas are discussed because of the often unwarranted increase in the frequency of their use. Evidence is presented using the Cochrane Systematic Review (2018) that reducing or eliminating lactose from infant formulas in infants with infantile colic is not always appropriate. Special low-lactose and lactose-free formulas replace lactose with glucose polymers such as maltodextrin, glucose syrup, and solid glucose syrup, which are produced by hydrolyzing starches (corn, rice, or potato). The article discusses the data on the effect of maltodextrin on the state of the intestinal mucosa, the microbiota of the large intestine and the possible role of this ingredient in the pathogenesis of chronic inflammatory bowel diseases. The results of various studies regarding the effect of maltodextrin on the intestinal microbiota are contradictory. However, special low-lactose or lactose-free products are prescribed in the presence of symptoms of lactase deficiency in an artificially fed baby. It is a major mistake to prescribe lactose-free mixtures on the basis of intact protein or partially hydrolysed ones for secondary lactase deficiency caused by an allergy to cow’s milk proteins. The carbohydrate component of Friso therapeutic hydrolysates contains no maltodextrin, and lactose is partially or completely replaced with glucose syrup.

Maltodextrin is a carbohydrate ingredient for the production of baby food

Организация искусственного вскармливания детей включает использование специализированных продуктов детского питания. Основными принципами создания адаптированных детских молочных смесей является приближение их к составу и свойствам женского молока и соответствие особенностям пищеварения и метаболизма ребенка. Немаловажным моментом при этом является адаптация углеводного компонента. В современных формулах детских адаптированных смесей часть лактозы заменена на мальтодекстрин. Целью настоящих исследований являлось изучение пищевой ценности, показателей безопасности отечественного углеводного ингредиента мальтодекстрина и возможности его применения в специализированной пищевой продукции для детского питания. Результаты исследований органолептических, физико-химических и микробиологических показателей опытного образца мальтодекстрина подтвердили соответствие требованиям, предъявляемым к углеводным ингредиентам для производства продуктов детского питания. При исследовании возможности использования отечественного мальтодекстрина в производстве адаптированных продуктов детского питания подтверждена его целесообразность для оптимизации углеводного состава готового продукта. The organization of artificial feeding of children includes the use of specialized baby food products. The main principles of creating adapted infant formula are to approach the composition and properties of human milk and to match the characteristics of the child's digestion and metabolism. An important point in this case is the adaptation of the carbohydrate component. In modern formulas of children's adapted mixtures, part of the lactose is replaced with maltodextrin. The purpose of these studies was to study the nutritional value, safety indicators of the domestic carbohydrate ingredient-maltodextrin and the possibility of its use in specialized food products for baby food. The results of studies of the organoleptic, physico-chemical and microbiological parameters of the maltodextrin prototype confirmed compliance with the requirements for carbohydrate ingredients for the production of baby food. When studying the possibility of using domestic maltodextrin in the production of adapted baby products, its expediency for optimizing the carbohydrate composition of the finished product was confirmed.

INVESTIGATION OF PRODUCTION-VALUABLE AND TECHNOLOGICAL PROPERTIES OF LEUCONOSTOCS FROM THE REPUBLICAN COLLECTION OF INDUSTRIAL STRAINS OF STARTER CULTURES AND THEIR BACTERIOPHAGES

We investigated the industrial important properties of leuconostocs that make them possible to use it in starter cultures for the dairy industry (fermented and gas-forming activities, resistance for NaCl, pH, sensitivity to bacteriophages, antagonistic activity against coliform bacteria). We have developed the nutritional medium for their cultivation with the justification of the carbohydrate component and identified cultivation temperature of microorganisms.

STUDY OF BIOLOGY AND NUTRITIONAL VALUE OF ULVA RIGIDA C. AG. AS A PROMISING TARGET SPECIES FOR MARINE AQUACULTURE

The haplodiplobion life cycle with sporic meiosis and isomorphic alternation of generations, the ability for vegetative reproduction, the rapid growth of thallus, a large amount of produced cells, and high specific production make Ulva rigida C. Ag. attractive for marine aquaculture. The paper is devoted to study biological features of Ulva growth and nutritional value under artificial conditions. It is shown how environmental factors affect the germination and formation of new plants. Preliminary data on nutritional value allow us to consider Ulva to low-calorie foods with a rich carbohydrate component. The mineral composition and a high concentration of iodine indicate the feasible usage of Ulva as a functional food ingredient.

Glucocerebrosidases catalyze a transgalactosylation reaction that yields a newly-identified brain sterol metabolite, galactosylated cholesterol

β-Glucocerebrosidase (GBA) hydrolyzes glucosylceramide (GlcCer) to generate ceramide. Previously, we demonstrated that lysosomal GBA1 and nonlysosomal GBA2 possess not only GlcCer hydrolase activity, but also transglucosylation activity to transfer the glucose residue from GlcCer to cholesterol to form β-cholesterylglucoside (β-GlcChol) in vitro. β-GlcChol is a member of sterylglycosides present in diverse species. How GBA1 and GBA2 mediate β-GlcChol metabolism in the brain is unknown. Here, we purified and characterized sterylglycosides from rodent and fish brains. Although glucose is thought to be the sole carbohydrate component of sterylglycosides in vertebrates, structural analysis of rat brain sterylglycosides revealed the presence of galactosylated cholesterol (β-GalChol), in addition to β-GlcChol. Analyses of brain tissues from GBA2-deficient mice and GBA1- and/or GBA2-deficient Japanese rice fish (Oryzias latipes) revealed that GBA1 and GBA2 are responsible for β-GlcChol degradation and formation, respectively, and that both GBA1 and GBA2 are responsible for β-GalChol formation. Liquid chromatography–tandem MS revealed that β-GlcChol and β-GalChol are present throughout development from embryo to adult in the mouse brain. We found that β-GalChol expression depends on galactosylceramide (GalCer), and developmental onset of β-GalChol biosynthesis appeared to be during myelination. We also found that β-GlcChol and β-GalChol are secreted from neurons and glial cells in association with exosomes. In vitro enzyme assays confirmed that GBA1 and GBA2 have transgalactosylation activity to transfer the galactose residue from GalCer to cholesterol to form β-GalChol. This is the first report of the existence of β-GalChol in vertebrates and how β-GlcChol and β-GalChol are formed in the brain.

Chemodivergent hydrogenolysis of eucalyptus lignin with Ni@ZIF-8 catalyst

Chemodivergent hydrogenolysis of eucalyptus biomass leading to 4-propanol- or 4-propyl-substituted phenols, together with a well-preserved carbohydrate component, was achieved by using Ni@ZIF-8 catalyst.