Rapid RP-HPLC/DAD Method for Progesterone and Estradiol in Milk: Validation and Application to Dairy Processing

Simple SummaryConsumption of food products that are rich in natural antioxidants improves the antioxidant status of an organism through protection against oxidative stress and damage. Milk and dairy products (yogurt and cheese) accounting for approximately 25–30% of the average human diet are undoubtedly a rich source of compounds exhibiting antioxidant properties. The aim of the study was to present a review of literature data on the antioxidant potential of raw milk and dairy products (milk, fermented products, and cheese) and the possibility to modify its level at the milk production and processing stage. The antioxidant capacity of milk and dairy products is mainly related to the presence of sulfur amino acids, whey proteins (especially β-lactoglobulin), vitamins A, E, and C, or β-carotene. The processes of fermentation or cheese maturation are associated with the release of bioactive peptides, which are responsible for the level of the antioxidant status of the product. The use of probiotic strains significantly enhances the antioxidant status. The antioxidant status of milk and dairy products can be modified with the use of natural additives in animal nutrition or at the stage of milk processing. Herbal mixtures, seeds, fruits, and waste from the fruit and vegetable industry are used most commonly. It is worth emphasizing that regular consumption of natural dairy antioxidants minimizes the risk of development of civilization diseases (e.g., cardiovascular disease, cancer, or diabetes). It also slows down the aging process in the organism.The aim of the study was to present a review of literature data on the antioxidant potential of raw milk and dairy products (milk, fermented products, and cheese) and the possibility to modify its level at the milk production and processing stage. Based on the available reports, it can be concluded that the consumption of products that are a rich source of bioactive components improves the antioxidant status of the organism and reduces the risk of development of many civilization diseases. Milk and dairy products are undoubtedly rich sources of antioxidant compounds. Various methods, in particular, ABTS, FRAP, and DPPH assays, are used for the measurement of the overall antioxidant activity of milk and dairy products. Research indicates differences in the total antioxidant capacity of milk between animal species, which result from the differences in the chemical compositions of their milk. The content of antioxidant components in milk and the antioxidant potential can be modified through animal nutrition (e.g., supplementation of animal diets with various natural additives (herbal mixtures, waste from fruit and vegetable processing)). The antioxidant potential of dairy products is associated with the quality of the raw material as well as the bacterial cultures and natural plant additives used. Antioxidant peptides released during milk fermentation increase the antioxidant capacity of dairy products, and the use of probiotic strains contributes its enhancement. Investigations have shown that the antioxidant activity of dairy products can be enhanced by the addition of plant raw materials or their extracts in the production process. Natural plant additives should therefore be widely used in animal nutrition or as functional additives to dairy products.

Induction of Lactation by Two Techniques: Success Rate, Milk Composition, Estrogen and Progesterone in Serum and Milk, and Ovarian Effects

vi 8000 liters of milk per cow in 305 days lactation. The experimental animals were divided into three groups (30 cows per group), according to the applied method for hormonal induction and synchronization of oestrus. In the first group, cows were treated by injection of synthetic prostaglandin (Dinolytic). Artificial insemination (AI) was performed in the detected induced oestrus. In the second group, cows were treated with a combination of synthetic prostaglandin and gonadotropnog-releasing hormone, GnRH (Ovsynch method). The cows were AI 14h to 16h after GnRH injection, without detection of induced estrus. The third group of cows was not hormone-treated (control), and AI were performed in a spontaneous estrus. All treatments are carried out within 40 to 90 days post partum. There was no statistically significant differences in the assessment of body condition and milk production between experimental groups of cows. Samples of venous blood and milk were taken from treated and control cows, on the application of prostaglandins, on the day of estrus/AI, and then on 7, 14, 21 and 35 days after the AI. The concentration of progesterone was determined in samples of blood and milk, and oestradiol in blood samples only. Statistical analysis was performed using ANOVA and ttest. The lowest concentration of progesterone in milk (Ovsynch = 5.8 1.5; Dinolytic = 5.4 0.3, control = 4.7 1.1ng/mL) and blood serum (Ovsynch = 1.8 1.2; Dinolytic = 0.3 0.1, control = 1.5 0.3ng / mL) were recorded on the day of estrus / AI, in all groups of cows. Increasing the concentration of progesterone in milk (Ovsynch: control, 13.4 5.7: 9.7 2.0 ng / mL, p <0.05) and blood serum (Ovsynch = 3.2 0.9; Dinolytic = 2.5 1.1, control = 3.2 1.3 ng / mL) were established on day 7 after the AI. In the pregnant cows, in each treatment group, progesterone concentrations remained elevated up to day 35 after the AI, compared to the day of estrus / AI (Ovsynch = 4.7 2.8; Dinolytic = 6.4 3.8, control = 4.1 2.1ng/mL). Concentrations of progesterone in milk and blood serum of nonpregnant cows of all three experimental groups, decreasing at day 21 after the AI. The highest concentrations of estradiol in blood serum were established on the day of estrus in pregnant cows of the control group (26.3 2.3 pg / mL) and the group of cows treated with prostaglandins (24.6 4.8 pg / mL). In cows treated with Ovsynch method, the concentration of estradiol on the day of VO was significantly (p <0.05) lower than in the control group of cows (Ovsynch = 16 1.6pg/mL, control = 26.3 2.36pg/mL). Performed hormonal treatments for post partum estrus induction and synchronization, significantly shortened the service period (Ovsynch = 76 days = 69 days Dinolytic; control = 83 days = 179 days Farma), calving interval (Ovsynch = 376 days = 363 days Dinolytic; Control = 382 days; Farm = 443 days) and increased the percentage of calving after first AI, compared to this value for the farm as a whole (Ovsynch = 57%; Dinolytic = 48%, control = 60%; Farm = 43.2%). The results show that the method of hormonal induction of post partum estrus, can significantly increase the reproductive efficiency of high-milking cows herds. This can significantly increase the level of milk and calf production per cow per year.

To detect the content of estrogen and progesterone in commercial milk in China and to compare the differences between commercial cows and traditional cows in the content of estrogen and progesterone of the milk, the breeding of cows and the process of milk production. Enzyme-linked immunosorbent assay (ELISA) was used to investigate the estrone, estradiol and progesterone in commercial and traditional milk, and literature review and field investigation was used to compare the differences of breeding and milk production. The mean concentration of estrone, estradiol and progesterone in Mongolian traditional cow milk was (98.5 +/- 12.4) pg/ml, (24.6 +/- 3.0) pg/ml and (0.2 +/- 0.3) ng/ml, respectively. The concentrations of estrone were (150.2 +/- 8.4), (131.3 +/- 16.3) and (128.9 +/- 13.0) pg/ml; The concentrations of estradiol were (35.4 +/- 2.2), (30.3 +/- 3.1) and (30.0 +/- 2.0) pg/ml; The concentrations of progesterone were (20.2 +/- 1.5), (18.1 +/- 2.2) and (16.5 +/- 2.4) ng/ ml, respectively. The content of estrogen and progesterone in commercial milks were higher than that in traditional milks (estrone comparison: t = 5.43, 19.23, 5.89; estradiol comparison: t = 4.14, 4.93, 14.03; progesterone comparison: t = 28.47, 32.73, 22.82; P < 0.05). Mongolian traditional cows did not lactate during the latter half of pregnancy. However, modern commercial cows might lactate almost in an entire period of pregnancy. Moreover, the lactating period was longer and milk production was higher in modern commercial cows than that in traditional cows. The content of estrogen and progesterone in commercial milk in Chinese market detected might be higher than that in traditional milk.

Vitamin concentrates with vitamins A and D are used for fortification of fluid milk. Although many of the degradation components of vitamins A and D have an important role in flavor/fragrance applications, they may also be source(s) of off-flavor(s) in vitamin fortified milk due to their heat, oxygen, and the light sensitivity. It is very important for the dairy industry to understand how vitamin concentrates can impact flavor and flavor stability of fluid milk. Currently, little research on vitamin degradation products can be found with respect to flavor contributions. In this review, the history, regulations, processing, and storage stability of vitamins in fluid milk are addressed along with some hypotheses for the role of vitamin A and D fortification on flavor and stability of fluid milk.

The purpose of this article is to analyze the technology of fermented dairy products, which is among the production technologies of milk and dairy products. As is well known, milk and dairy products are among the most important nutrients for growing, developing and leading a healthy lifestyle. In order to make the most of the important human qualities of milk, a number of technologies are used to increase its durability, protect the health of consumers and obtain various dairy products. Thanks to these rapidly developing production technologies from the past to the present, it has become possible to obtain more standard and high-quality milk and dairy products. The article examines milk and its composition, the importance of milk and dairy products for human health, the development of milk and dairy products, the main technologies of milk production, research in the field of fermented milk technology, written scientific works and articles on milk and dairy products. The information contained in the portals of the engaged enterprises was used. The article examines milk and its composition, the importance of milk and dairy products for human health, the development of milk and dairy products, the main technologies of milk production, research in the field of fermented milk technology, written scientific works and articles on milk and dairy products. The information contained in the portals of the engaged enterprises was used. The technologies used in the processing of milk and dairy products affect both the quality and consumption of these products, as well as the health of producers. Recently, new technologies used in the processing of milk and dairy products are considered important in terms of the quality of the products obtained. The article examines the features of these technologies, the processing process and the specifics of the products obtained. This is important for both researchers and consumers interested in dairy processing. As a result, it is noted that in recent years there has been a significant increase in interest in the impact of milk and dairy products on human health. Today, such products are called functional, that is, products that have an impact on health in addition to their nutritional value. It is emphasized that the technologies used to preserve the nutritional value of milk and clean it from bacteria harmful to human health are gradually developing. This increases the consumption of milk and dairy products and maximizes their health benefits.

The paper establishes that in the legal field of Ukraine there are more than 50 legal and regulatory acts that are directly or indirectly related to the regulation of the dairy industry market. The Law of Ukraine "On Milk and Dairy Products" is basic in the field of regulation of the dairy industry. The legislator fixed the interpretation of the main terms of the dairy industry in the relevant legal act - the Law of Ukraine "On Milk and Dairy Products". This act defines what "raw milk", "dairy raw materials", "dairy products", "traditional dairy products" are. Also, the legislator fixed the main institutions of the state policy of ensuring the safety and quality of milk and dairy products. In addition, the act discloses the issue of state support for producers of milk, dairy raw materials and dairy products and the mechanism for its implementation. It should be noted that the Law of Ukraine "On Milk and Dairy Products" regulates the legal and organizational foundations for ensuring the safety and quality of milk and dairy products for life and the health of the population and the environment during their production, transportation, processing, storage and sale, import into the customs territory and export from the customs territory of Ukraine. The study identified the main, in our opinion, regulatory legal acts that regulate the supply of milk, dairy raw materials and dairy products to the state, and also characterized their purpose, main provisions and meaning. It was found that milk and dairy products occupy a significant place in the market of food resources. It is noted that the production of dairy products is an important component of food security. It was found that providing the state with milk is a complex process that includes the following stages: milk production, milk processing, sale of dairy products, state regulation.

Potential strategies to enhance conjugated linoleic acid content of milk and dairy products: A review

Milk Progesterone as a Diagnostic Aid

Introduction. The article analyses current trends in milk production and consumption in the world, taking into account the latest factors of product competitiveness in the global milk market and the growing interest of consumers in plant substitutes for animal milk. According to the Food and Agriculture Organization of the United Nations, world dairy production continues to grow, with Asia experiencing the largest increase since 2019. The next decade will create great opportunities for the dairy industry in the world. The increase in demand will be accelerated by the globalization of the industry, which will form consolidation in order to efficiently use resource potential, ensure a sustainable supply of milk and stable profits for producers. Purpose. The purpose of the article is to study current trends in milk production and consumption in the world, taking into account the latest factors of product competitiveness in the global milk market and the growing interest of consumers in plant substitutes for animal milk. Method (methodology).The methodological basis of the study is scientific work on the current state and trends in production and milk consumption in the world. Dialectical, systemic and synergetic approaches were used at all stages of the study; methods of general scientific knowledge: comparison, analysis and synthesis, induction and deduction. Statistical analysis was used as specific methods. Results. The results of the study allowed us to draw conclusions about the social significance of dairy production. Globalization with a significant impact on domestic and international trade in the dairy industry will accelerate in the coming years, as more and more consumers seek to include dairy products in their daily diet to promote good quality and healthy natural products. One of the current trends in the world food market is a significant increase in consumption of plant foods. At present, each country faces a difficult task to develop an effective strategy for the development of natural dairy products in such conditions. The development of the world dairy market is influenced by various factors that determine the volume of production and consumption of dairy products, associated primarily with global changes in consumer preferences, increasing demand for goods in cheaper price segments, population growth, especially in developing countries, as well as economic development and overall welfare of mankind. In the context of globalization, an important factor in the world market is the economic policy of major countries that export and import milk and dairy products. In recent years, trade wars have begun to intensify, in particular between key players in the global market, which negatively affects the market for natural milk and dairy products and hinders its development. as well as with economic development and the general growth of human well-being. In the context of globalization, an important factor in the world market is the economic policy of major countries that export and import milk and dairy products. In recent years, trade wars have begun to intensify, in particular between key players in the global market, which negatively affects the market for natural milk and dairy products and hinders its development. As well as with economic development and the general growth of human well-being. In the context of globalization, an important factor in the world market is the economic policy of major countries that export and import milk and dairy products. In recent years, trade wars have begun to intensify, in particular between key players in the global market, which negatively affects the market for natural milk and dairy products and hinders its development.

ABSTRACTA radioimmunoassay (RIA) method for progesterone has been developed. It has been validated for the determination of progesterone in cow skim milk. The main reagents used in the development work were prepared and characterized in-house. The assay uses a radioiodinated tracer purified by gel filtration on Sephadex G-25, standards prepared in skim milk and coated tubes with specific antibodies as the solid phase (separation system). The radiochemical purity of the tracer was greater than 95%, the maximum binding using solid phase reached 43% and the nonspecific binding didn’t exceed 5%. Series of progesterone standards using milk matrix with concentration ranging from 0 to 40ng/mL were prepared. Detection limit of the assay was 0.13ng/mL and the precision evaluation gives an intra and inter-assay coefficient variations between 4.94% and 12.66%. The recovery obtained with skim milk samples was 84% to 119% and the parallelism test indicated good linearity (R2 > 0.99). The clinical tests give high correlation coefficient (r = 0.998) between progesterone concentrations of cow’s skim milk assayed using developed progesterone RIA kit and commercial progesterone RIA kit.

The purpose of the study is to identify the main trends in the formation and use of the resources of milk and dairy products in Russia, changes in the volume and structure of exports of milk and dairy products, including ice cream, as well as to assess the impact of factors on income from exports of milk and dairy products, ice cream. Economic-statistical and balance-sheet research methods were used. To assess the impact of factors on export revenues, the index method and the method of deterministic factor analysis (the method of chain substitutions) were used. Results. The economic availability of milk and dairy products is decreasing, taking into account structural shifts in milk production by category of farms, stable imports (at the level of 16.76–17.97 % of the formed milk and dairy products resources in 2017-2022) and increasing exports of products. The volume of exports of products in 2022 decreased both in physical and value terms. However, the main export directions remained the same – Kazakhstan, Georgia, Azerbaijan, Uzbekistan, Armenia, Kyrgyzstan, Tajikistan, Belarus. At the same time, exports increased to countries with high product prices, including China. In the Chinese market, dairy products from Russia account for only 0.075–0.087 % of total imports. At the same time, it was revealed that for certain commodity items, Russia can compete in price in the Chinese market with its traditional supplier, New Zealand. The article indicates that the export of milk products, dairy products and ice cream from Russia can only be a tool for selling surplus products, in the future it is necessary to create conditions for increasing milk production, replacing imports and increasing the economic accessibility of dairy products for the population of the country. The scientific novelty lies in assessing the impact of quantitative, structural (assortment, geographical) factors on Russia's export revenues for milk, dairy products and ice cream in value estimation, as well as identifying Russia's price advantages relative to other importers of China.

The expansion of production of dairy processing enterprises and construction of dairy farms is an important task in the market of milk and dairy products of the Republic of Kazakhstan. Not only ready-made dairy products are imported into the country, but also raw milk, since their personal subsidiary farms cannot meet the needs for milk volumes, and therefore it is important to invest in milk production and processing. The purpose of the study, the main directions and ideas of scientific research are to identify problems in the dairy industry based on current research on the milk and dairy products market in the Republic of Kazakhstan and to identify areas for improving the production base of dairy products. The scientific significance of the research is to improve the production base of milk and dairy products, to better understand the problems in the dairy industry based on the effective development and increase the competitiveness of domestic dairy products. The scientific significance of the research is to improve the production base of milk and dairy products, to better understand the problems in the dairy industry based on the effective development and increase the competitiveness of domestic dairy products. The practical significance lies in the fact that the main provisions of the article can be used to solve problems of increasing the efficiency of milk production by government agencies and the development of development strategies by economic entities producing dairy products.

The AOAC Stakeholder Panel on Strategic Food Analytical Methods approved Standard Method Performance Requirements (SMPR®) 2018.009 for lactose in low-lactose or lactose-free milk, milk products, and products containing dairy ingredients. The LactoSens®R Method is a biosensor assay kit developed for the determination of lactose in a variety of lactose-free or low-lactose milk, dairy, and infant formula products produced with yeast-neutral lactases. In response to a call for methods, the LactoSensR method was validated in a single laboratory study with comparison to SMPR 2018.009. The LactoSensR method was evaluated for calibration, interference, repeatability, recovery, and robustness. In a method comparison study samples naturally containing low levels of lactose were evaluated using LactoSensR and an accredited high-performance anion-exchange chromatography with pulsed amperometric detection. Calibration with lactose standard solutions was shown to be linear and the method was shown to be free of interference from a variety of sugars, vitamins, alcohols, flavorings, and other compounds. Matrix studies, including 85 spiked materials, 55 products naturally containing lactose, and 13 reference materials, resulted in RSDr of 0-10.5% at 8-100 mg lactose/100 g and 0.2-5.4% at >100 mg lactose/100 g for milk and dairy products and 1.0-6.8% for infant formula, in compliance with SMPR 2018.009 with few exceptions. Recovery was 85.0-110.3% at 8-100 mg lactose/100 g and 85.6-109.7% at >100 mg lactose/100 g for milk and dairy products and 91.1-97.0% for infant formula, also meeting the performance requirements with few exceptions. The method was shown to be robust to changes in ambient temperature, sample temperature, and sample volume. The LactoSensR method compares favorably with the requirements of SMPR 2018.009 and should be adopted as a First Action AOAC Official MethodSM. The LactoSensR method is a fast, easy-to-use method that meets the requirements of SMPR 2018.009.

Milk and dairy products are an important food in the human diet. The present investigation was carried out to determine concentrations of lead, cadmium, zinc, copper and iron in milk and dairy products and evaluate the potential health risks of metals to humans via consumption of milk and dairy products. A total of 77 samples of milk and dairy products (22 raw milk, 20 kareish cheese, 21 butter and 14 rice pudding) were collected from farms, individual farmers and dairy shops in Beni-Suef governorate, Egypt. Pb, Cd, Zn, Cu and Fe concentrations in milk and dairy products ranged from 0.044–0.751, 0.008–0.179, 0.888–18.316, 0.002–1.692 and 1.3208–45.6198 ppm respectively. Pb concentration in all samples exceeded the maximum permissible limit (0.02 mg/kg) established by codex standard. Pd and Cd intake through milk and dairy products consumption were 1.27 and 0.33 μg/kg bw/day, which represent 35.3 and 39.8 % of the tolerable daily intake. Dairy products are poor sources of iron, copper and zinc, and milk contributes little to the total iron and zinc intake. Target hazard quotient values of less than 1 indicate a relative absence of health risks associated with the consumption of milk and dairy products.