Hydrolysate of ovalbumin: production and evaluation of the functional properties of peptides

Chicken eggs proteins and their derivatives, like protein hydrolysates, peptides and amino acids, possess high nutritional value and provide a wide range of biological activity. They serve as sources for development of functional ingredients that draw the attention of specialists in the food production and biomedical industries, as well as the livestock feed industry. Enzymatic hydrolysis of proteins is a popular process for obtaining bioactive peptides with multifunctional properties. The purpose of this study is to obtain a hydrolysate of ovalbumin with a high degree of hydrolysis and to determine its functional and technological parameters. The research presents a two-stage scheme of ovalbumin hydrolysis with the help of pepsin and trypsin which provide high degree of hydrolysis (82–83%). The fractional composition of the hydrolysate is determined. The fractional composition is represented by three main fractions (high, medium and low molecular weight). The summarized antioxidant activity (SAA) of the hydrolysate is considered within the dynamics of the hydrolysis process. The highest SAA value was noted after 2 hours, and it amounted to 170.23 mg/l; at the end of hydrolysis the SAA value was equal to 114.31 mg/l. When analyzing the SAA, it was found that the main contribution to the summarized antioxidant activity of the ovalbumin hydrolysate is made by peptides of the medium molecular fraction. The microfiltration process, used in the research, made it possible to separate high-molecular compounds, which led to an increase in the SAA of the hydrolysate to 189.9 mg/l. The main functional and technological parameters of the hydrolysate are determined in this research. The comprehensive study of the biological activity and functional characteristics of egg protein hydrolysates and their peptides provides a theoretical basis for expanding the range of functional ingredients obtained from food proteins and for replenishing the range of functional foods.Chicken eggs proteins and their derivatives, like protein hydrolysates, peptides and amino acids, possess high nutritional value and provide a wide range of biological activity. They serve as sources for development of functional ingredients that draw the attention of specialists in the food production and biomedical industries, as well as the livestock feed industry. Enzymatic hydrolysis of proteins is a popular process for obtaining bioactive peptides with multifunctional properties. The purpose of this study is to obtain a hydrolysate of ovalbumin with a high degree of hydrolysis and to determine its functional and technological parameters. The research presents a two-stage scheme of ovalbumin hydrolysis with the help of pepsin and trypsin which provide high degree of hydrolysis (82–83%). The fractional composition of the hydrolysate is determined. The fractional composition is represented by three main fractions (high, medium and low molecular weight). The summarized antioxidant activity (SAA) of the hydrolysate is considered within the dynamics of the hydrolysis process. The highest SAA value was noted after 2 hours, and it amounted to 170.23 mg/l; at the end of hydrolysis the SAA value was equal to 114.31 mg/l. When analyzing the SAA, it was found that the main contribution to the summarized antioxidant activity of the ovalbumin hydrolysate is made by peptides of the medium molecular fraction. The microfiltration process, used in the research, made it possible to separate high-molecular compounds, which led to an increase in the SAA of the hydrolysate to 189.9 mg/l. The main functional and technological parameters of the hydrolysate are determined in this research. The comprehensive study of the biological activity and functional characteristics of egg protein hydrolysates and their peptides provides a theoretical basis for expanding the range of functional ingredients obtained from food proteins and for replenishing the range of functional foods

Structural features and formation of lower Cretaceous AV[1] layer in the Soviet oil field (Tomsk Oblast)

The analysis of the collected geological and geophysical information on AV[1] layer known as Ryabchik formation is carried out. The facial conditions of this formation which define structural features of "Ryabchik" sandstones formations are considered. Maps characterizing permeability and porosity of reservoir are plotted. Areal tracking technique of sand streaks is given

A method development for improving the stability of vegetable polyphenol complexes for semi-finished minced meat products with antioxidant effect

Polyphenolic vegetable complexes are active antioxidants and play an important role in the processes of free radicals quenching in the human body. The aim of the work was to develop an immobilization method as a way for improving the stability of polyphenols in dried cowberry squeezing extract (DCSE) and to develop semi-finished minced meat products with antioxidant effect without changing their nutritional value. Experiments were carried out to study the nutritional value of DCSE. The presence of a large number of polyphenolic compounds in DCSE and a high radical-binding ability of the extract were revealed. Based on the mathematical planning method, an offal paste composition was obtained, which was used to obtain pellets, and the formulation of semi-finished minced meat products with pellets was optimized. It was established that preliminary immobilization of DCSE on offal pellets components allows to increase the level of total antioxidant content in the minced meat. Subsequent heat treatment of semi-finished minced meat products produced from such minced meat showed an increase in stability and, thus, bioavailability of antioxidants and the possibility of obtaining a finished product with antioxidant effect. The antioxidant effect of cowberry squeezing extract in the meat system is proved: accumulation of lipid oxidative decomposition products in the meat system during storage of frozen semi-finished minced meat products was inhibited to a greater extent when using offal pellets with immobilized compounds of cowberry squeezing extract. This work was carried out as part of the State Assignment of the Ministry of Education and Science of the Russian Federation No. 19.5486.2017/BCh and the «Young Scientists of ESSTU‑2019» grant

Estimation of the repair efficiency of collagen matrices on the model of thermal burn

Background. In the world, dozens of new local wound healing agents are developed and improved every year, which undergo preliminary tests on laboratory animals due to the presence of common phases of the course of the wound process with humans.The aim of the study was to evaluate the wound healing effect of matrices obtained on the basis of the recycling of collagen-containing waste.Materials and methods. Collagen matrices are obtained from substandard leather raw materials subjected to treatment with fermented milk composition (KM1) and lactic acid (KM2). The wound healing effect was studied on the model of thermal burns on Wistar rats in 5 groups: 1st – control (natural wound healing); 2nd – experimental 1 (processing KM1); 3rd – experimental 2 (processing KM2); 4th – experimental 3, comparison group (“Levomekol”) and 5th – intact animals (normal, without burns). Wound healing was assessed by the results of planimetry on days 1, 3, 5, 7, 9, and 13 and by histological analysis of the skin tissue on days 6, 13, and 20. On days 6 and 13, the summary antioxidant activity, the total content of leukocytes, erythrocytes, the activity of the catalase enzyme, and the content of malondialdehyde were determined in the blood of rats.Results. With thermal damage to the skin, an IIIA degree burn was formed, accompanied by the development of dry coagulation necrosis. The use of collagen matrices restored the total content of leukocytes, reduced the area of the burn wound, normalized the content of malondialdehyde, the total antioxidant activity and the activity of catalase in the blood. Histomorphometric studies have confirmed the dynamics of skin tissue recovery after a burn. The effectiveness of the use of matrices was comparable to the pharmacopoeial drug “Levomekol”. A higher wound healing effect was noted when using the KM1 matrix.Conclusion. On the model of thermal burn, the wound-healing effect of collagen matrices was established, as evidenced by the results of restoring the number of leukocytes, reducing the area of the burn wound and restoring the histostructure of the skin. One of the molecular and cellular mechanisms of wound healing is the inhibition of lipid peroxidation reactions and the restoration of the antioxidant potential of the body

Structural features and formation of lower Cretaceous AV[1] layer in the Soviet oil field (Tomsk Oblast)

The analysis of the collected geological and geophysical information on AV[1] layer known as Ryabchik formation is carried out. The facial conditions of this formation which define structural features of "Ryabchik" sandstones formations are considered. Maps characterizing permeability and porosity of reservoir are plotted. Areal tracking technique of sand streaks is given

Catamnesis of children from mothers who had A(H1N1)pdm09 influenza during pregnancy

The aim of this study was to assess 5-years catamnesis of children from mothers who had A(H1N1)pdm09 influenza during pregnancy. The design of the research: cohort cross-sectional retrospective "case - control" study. The study group included 227 children of mothers who had A(H1N1)pdm09 influenza during pregnancy, and the control group was consisted of 227 children whose mothers didn't have A(H1N1)pdm09 influenza in epidemic period during pregnancy. It was shown that 11,9 % of children born to mothers with influenza infection during pregnancy vs 1,8 % of children of the control group to 5-year age formed a cohort of patients with recurrent respiratory tract infections (p < 0,001). Acute respiratory infections were complicated by pneumonia in 15,4 % of study group children vs 8,8 % of children in the comparison group (p = 0,044). We founded a significant association between maternity A(H1N1)pdm09 influenza during 1st and 2nd trimesters of gestation and increased frequency of asthma in their children

A method development for improving the stability of vegetable polyphenol complexes for semi-finished minced meat products with antioxidant effect

Polyphenolic vegetable complexes are active antioxidants and play an important role in the processes of free radicals quenching in the human body. The aim of the work was to develop an immobilization method as a way for improving the stability of polyphenols in dried cowberry squeezing extract (DCSE) and to develop semi-finished minced meat products with antioxidant effect without changing their nutritional value. Experiments were carried out to study the nutritional value of DCSE. The presence of a large number of polyphenolic compounds in DCSE and a high radical-binding ability of the extract were revealed. Based on the mathematical planning method, an offal paste composition was obtained, which was used to obtain pellets, and the formulation of semi-finished minced meat products with pellets was optimized. It was established that preliminary immobilization of DCSE on offal pellets components allows to increase the level of total antioxidant content in the minced meat. Subsequent heat treatment of semi-finished minced meat products produced from such minced meat showed an increase in stability and, thus, bioavailability of antioxidants and the possibility of obtaining a finished product with antioxidant effect. The antioxidant effect of cowberry squeezing extract in the meat system is proved: accumulation of lipid oxidative decomposition products in the meat system during storage of frozen semi-finished minced meat products was inhibited to a greater extent when using offal pellets with immobilized compounds of cowberry squeezing extract. This work was carried out as part of the State Assignment of the Ministry of Education and Science of the Russian Federation No. 19.5486.2017/BCh and the «Young Scientists of ESSTU‑2019» grant