Research of technological features of production of functional fermented milk products

The most important factor determining human health is nutrition. Functional products containing many valuable ingredients contribute to the strengthening and maintenance of human health. In this regard, over the years, the development of technology for the production of such products does not lose its relevance. The authors selected the composition and ratio of probiotic microflora in the composition of a complex starter culture for the production of a functional fermented milk product. Two variants of complex starter culture were selected containing Streptococcus salivaris subsp. thermophilus, Bifidobacterium subsp. lactis (BB-12) and Lactobacterium casei subsp. casei in a ratio of 4: 1: 1 and Streptococcus salivaris subsp. thermophilus, Bifidobacterium bifidum and Lactobacillus acidophilus in a 4: 1: 1 ratio. The paper considers the influence of individual technological factors on the quality formation of the finished product, such as the dose of the prebiotic galactooligosaccharides (GOS), the dose of the concentrate of whey protein (CWP) and the fermentation temperature of the milk mixture. The following technological factors of production have been established: doses of introduced components (GOS - (1 ± 0.1) %, CWP (2.0 ± 0.5) % and the fermentation temperature of the mixture (38 ± 2) °C. The results of the study will be used further in the development of technology for a functional fermented milk product.

Laser Fluorescence and Extinction Methods for Measuring the Flow and Composition of Milk in a Milking Machine

Automation of milking systems is linked to accurate measurement of fluctuations in milk flow during milking. To assess the fluctuations of the milk flow, the formation and movement of milk portions in the milking machine-milk pipeline system was studied. By considering the movement of a milk plug along the milk pipeline, a hydraulic model of the formation of a critical volume of milk in the milking machine manifold was compiled. In practice, the most expedient way of determining milk flow parameters may be to measure the laser fluorescent and extinction responses of moving air-milk mixture. We have implemented a new laser sensing method for measuring the flow rate and composition of milk on the basis of counting the optical response pulses received from moving dispersed components by a CCD array or a randomized fiber optic bundle. Using the developed laser sensors, the theoretical model of milk flow was tested.

Early Feeding Practices and Body Mass Index Z-Score among Saudi Preschoolers: A Cross-Sectional Study

ObjectivesTo characterize early feeding practices among mothers in Saudi Arabia and examine their associations with child birthweight and BMI z-score (BMIz) at preschool. Study DesignCross-sectional study. MethodsMother-child dyads (n=209) were recruited from different preschools around the city of Jeddah. Mothers completed the study questionnaire over the telephone and preschoolers’ anthropometric measurements were objectively measured. Descriptive statistics were used to characterize early feeding practices. Bivariate analyses and linear regression were used to examine the association of early feeding practices with child birthweight and BMIz at preschool. ResultsThe majority of mothers (92.3%) initiated breastfeeding, with an average duration of 9.34 months (SD= 8.04). About half of the mothers reported that they have offered fruit juice and/or date syrup-milk mixture in a baby bottle (52.2% and 45.9% respectively), with an average duration of 11.5 months (SD= 7.73) and 5.90 months (SD= 6.13), respectively. Children who were offered fruit juice and/or date syrup-milk mixture in a baby bottle had significantly lower birthweights compared to children who were not (M= 2.79, SD= 0.59 vs. M= 3.06, SD=0.69, P< 0.01 and M= 2.79, SD= 0.67 vs. M= 3.03, SD=0.62, P< 0.01, respectively). There was a negative association between introducing fruit juice in a baby bottle and child BMIz at preschool (b: 0.18, 95% confidence interval (CI): -0.83, -0.11); This association was not significant after adjusting for child birthweight and other covariates (b: -0.10, 95% CI: -0.64, 0.09). ConclusionLongitudinal and interventions studies are needed to inform counseling guidelines and community campaigns in order to improve early feeding practices in the region.

Application of the accelerated storage method for functional dry milk mixtures

В работе приведены результаты исследований сухой молочной смеси функционального назначения, подвергнутой хранению в течение 6 мес при аггравированных температурных режимах (20±2) °С, (35±2) °С, (55±2) °С и при постоянной относительной влажности воздуха 85 %. В результате было отмечено, что применение температуры хранения 55±2 °С позволяет подтвердить заявленный срок годности продукта с учетом коэффициента резерва, так как именно при данной температуре хранения отмечено изменение показателей окислительной порчи, гидролиза белка и органолептических показателей, которые оценивались по дескрипторно-профильному методу согласно ГОСТ ISO 16779-2017. The paper presents the results of studies of a dry milk mixture for functional purposes, stored for 6 months at aggravated temperature conditions (20±2) °C, (35±2) °C, (55±2) °C and at a constant relative air humidity of 85 %. As a result, it was noted that the use of a storage temperature 55±2 °C allows confirming the declared shelf life of the product, taking into account the reserve coefficient, since it is at this storage temperature that a change in indicators of oxidative deterioration, protein hydrolysis and organoleptic indicators, which were assessed by descriptor profile method according to GOST ISO 16779-2017.

Preliminary study on the construction of animal model for non-puerperal mastitis

Objection: This qualitative study explored the key factors affecting the occurrence of non-puerperal mast (NPM） and the construction of an animal model which is closer to the characteristics of the disease.Background: The etiological factors and pathogenesis of NPM are unknown, and the incidence, misdiagnosis rate and recurrence rate are high. Previously reported modeling methods vary, reproducibility is poor, and disease characteristics cannot be well characterized, so new animal models are urgently needed for research.Methods: In this study, using female Wistar rats to construct a non-puerperal mastitis animal model by intraperitoneal injection of metoclopramide to simulate hyperprolactinemia + autologous milk injected into the mammary gland to simulate ductal secretions. Results: Pathological results showed that 2 weeks after injection in group C (intraperitoneal injection of metoclopramide for 2 weeks + breast injection of maternal milk mixture twice) and group D (intraperitoneal injection of metoclopramide for 2 weeks + breast injection of maternal milk mixture three times), lipid stasis, periductal inflammation, and massive plasma cell and lymphocyte infiltration were observed,similar to the lesions in patients with human plasma cell mastitis. Conclusions: We believe that we can can establish a non-puerperal mastitis model by altering prolactin levels and ductal secretion stasis in rats.

Influence of Amino Acid Substitutions in a Recombinant Cow Chymosin Molecule on the Dependence of its Coagulation Activity on the Concentration of Calcium Chloride in Milk

The influence of substitutions of amino acids involved in the formation of salt bridges on the cow chymosin technological properties has been studied. It was shown that point amino acid mutations Asp198→Lys, Asp156→Val and their combination decrease the sensitivity of coagulation activity of engineering recombinant chymosins to change in the concentration of calcium chloride in milk in the range of 1-5 mM. The found effect is a positive technological evidence in terms of cheese making, since it allows varying the content of calcium chloride added to the milk mixture without a threat of significant changes in the undesired proteolytic activity of used milk-clotting enzyme. recombinant chymosin, technological properties, amino acid substitutions, milk-clotting activity, concentration of calcium chloride. The work was performed within the framework of the state task of the Ministry of science and higher education of the Russian Federation (topic number fzmw-2020-0002, "Development of recombinant enzyme producers for cheese making").

Research of rheological properties of fermented milk ice cream with high content of exopolysaccharides

As a result of scientific and technological research, the ingredient composition and the feasibility of using complex bacterial starter cultures as part of fermented milk ice cream have been substantiated. The objects of the study were samples of mixtures for the production of fermented milk ice cream were considered, which included dairy and non-dairy components, including complex bacterial starter cultures: YF-L812 (Streptococcus thermophilus, Lactobacillus bulgaricus) - control sample and YO-PROX 777 (Streptococcus thermophilus, Lactobacillus delbrueckii ssp.bulgaricus), as well as pectin stabilizers “Grindsted Pektin LC 710” and “Cremodan SE 334” with a concentration of 0.1-0.7%. It was found that a prototype sample with starter culture YO-PROX 777 has increased values of dynamic viscosity compared with the control sample with similar stabilizers and their identical concentrations, which is evidence of the accumulation of exopolysaccharides in the fermented fermented milk mixture. A prototype of fermented milk ice cream has better shape stability during temperature control, the thawing rate is reduced by 1.6 times compared to the control. The degree of overrun of the prototype fermented milk ice cream is 37.6%, which is 1.2 times higher compared to the control.

The Use of Topinambur (Jerusalem artichoke) Concentrate in the Curd Production

Curd production technology upon the use of topinambur (Jerusalem artichoke) tuber has been developed. For the curd production, hydrolyzed concentrate obtained from the tuber of Jerusalem artichoke has been used in the form of herbal supplement. New food product exceeds the traditional one in its biological values due to enrichment with carbohydrates, vitamins, nonessential and essential amino acids. The optimal dose of introducing the hydrolyzed concentrate has been also determined. The use of hydrolyzed concentrate of Jerusalem artichoke solution reduces the coagulation duration of milk mixture and increases the product yield; at the same time it saturates the product with inulin.