Oxylipins - biologically active substances of food
Oxylipins are biologically active molecules that are formed in all aerobic organisms enzymatically or as a result of the action of free radicals and reactive oxygen species. The value of oxylipins for plants is comparable to the value of eicosanoids for animals and humans. In the human organism, the oxylipins’ formation occurs through enzymatic or non-enzymatic oxygenation of various ω-6 and ω-3 polyunsaturated fatty acids (PUFAs) obtained from food. Being “local hormones”, oxylipins are involved in the regulation of inflammation, pain response, cell adhesion, migration and proliferation, apoptosis, angiogenesis, regulation of blood pressure, blood coagulation, and blood vessel permeability. There is a hypothesis that the molecular structure of oxylipins allows them to be positioned as adaptogens and justifies the use of plants as potential sources of oxylipins in traditional medicine.
The aim of this research is a brief analytical review of publications characterizing the adaptogenic potential and promising sources of oxylipins (plant, cyanobacteria, and algae).
Results. The publications of the last decade indicate an increased interest in the oxylipins of plants, cyanobacteria, and algae. In total, about 150 oxylipins and their derivatives are known in plants and fungi. Of the plant sources of oxylipins, Peruvian poppy root (Lepidium meyenii), white bryony (Bryonia alba L.), blackcurrant seed oil (Ribes nigrum), and licorice (Glycyrrhiza glabra) are of particular interest. Some macroalgae are capable of non-enzymatically or enzymatically synthesizing a variety of oxylipins, including antiinflammatory prostaglandins, resolvins, and leukotrienes. In addition, to common oxidized derivatives of fatty acids, macroalgae also contain a number of complex and unique oxylipins. Other sources of oxylipin producers include macroscopic gelatin colonies of freshwater cyanobacteria Aphanothece sacrum. As the analysis of the presented in the review publications showed, most anti-inflammatory and pro-resolvent oxylipins have antiproliferative properties, have adaptogenic potential, and can protect the body at the system level, contributing to the formation of favorable bacterial clearance.
Conclusion. The results of numerous studies indicate that plants, algae, and even bacteria can be a promising source of oxylipins, both for their use in their native form and for the targeted isolation of oxylipins from them in order to conduct further studies of their adaptogenic potential, cardio- and geroprotective properties. In the future, establishing the adequate daily intake of these substances and the development on their basis of dietary preventive and specialized products for various purposes will be relevant.
The effect of pectin of tansy, Tanacetum vulgare L., on anxiety and overeating food rich in fats and sugars in mice in modelling binge eating
Binge eating is repeated episodes of eating large amounts of sweet and fatty food in short periods. Dietary fibers, including pectin, significantly reduce the subjective ratings of hunger, and the amount of food eaten. However, studies showing the effect of dietary fibers on satiety use juices or yoghurts with added dietary fiber, or a kissel-like food. Thus, there is a lack of data on the effect of dietary fibres on binge eating of palatable food.
The aim of the study was to assess the effect of tansy pectin on anxiety and the binge eating of palatable food in mice.
Material and methods. 64 mice weighing 33.3±0.6 g were divided into two groups. Binge eating was induced in forty mice of the first group by consumption of sunflower halva (SH) in addition to regular chow for 24 h once a week. The total energy intake and separately the consumption of regular chow (RC) and SH were monitored. Tansy pectin in the form of an aqueous solution was administered to the mice using a gastric feeding tube (50 mg/kg body weight) before the last presentation of SH. Blood was obtained by cardiac puncture at the end of the last 24 h SH access period. The concentration of insulin and ghrelin in plasma samples were determined by the enzyme immunoassay. In animals of the second group, 24 hours after the administration of pectin, the level of anxiety and depression of mice was assayed with an open field test, a light-dark box test, an elevated plus-maze test, and a forced swim test. Throughout the study, water was used as a negative control, and imipramine at a dose of 20 mg/kg was used as a positive control.
Results. Mice treated with tansy pectin ate 2.6 fold less SH within 3 h and 1.4 fold less within 24 h after oral administration of tansy pectin compared to control (water administration). Consumption of RC did not differ within 3 or 24 h. The total energy intake was 1.9 fold lower within 3 h in mice treated with tansy pectin. Within 24 h after pectin oral administration the total energy intake did not differ from control. Insulin plasma level was 2.5 fold lower and ghrelin plasma concentration was 25% higher in the mice that received pectin compared to control, at the end of the 24 h SH access period. The administration of tansy pectin was found to decrease anxiety-related behaviour in mice. Its administration significantly increased the time spent in the central sector of the open field apparatus by 87%, the time spent in the light area of the light-dark box by 31%, and the time spent on the open arms of the elevated plus maze by 22% compared with the control.
Conclusion. Overall, tansy pectin reduced the binge eating of SH representing highly palatable, sweet, and fatty food. Reduced intake SH lead to a decrease in insulin concentration. Blood level of ghrelin was increased in mice treated with tansy pectin at the end of the sweet and fatty food presentation period. Tansy pectin reduced the level of anxiety in mice.
Risk factors for carbohydrate metabolism disorders from a chronobiological position
A steady increase in the prevalence of carbohydrate metabolism disorders is closely related to overweight and obesity. Obesity is associated with a sedentary lifestyle, poor diet, sleep disturbance, which can lead to dysfunction of circadian rhythms with a decrease in the production of the hormone melatonin.
The aim of the study is to clarify the most significant risk factors for carbohydrate metabolism disorders in obese patients from the standpoint of chronobiology.
Material and methods. The retrospective study involved 120patients with obesity (body mass index 31.35±3.80 kg/m2) with early disorders of carbohydrate metabolism (EDCM), type 2 diabetes mellitus (T2DM) and without disorders of carbohydrate metabolism (n=40 in each group). The age of the patients was 40-69 years, of which 75% were women and 25% were men. The patients’ food diaries (for 24 hours) and Horne-Ostberg tests were analyzed. Fasting glucose, glycated hemoglobin, leptin, insulin were determined in the venous blood plasma; the insulin resistance index (HOMA-IR) was calculated, anthropometric indicators, basal body temperature (BT) were measured.
Results and discussion. Patients of all groups were comparable in age, sex, BMI. The patients had an irrational distribution of the amount of calories consumed during the day, frequent meals, and a tendency to late breakfast (9:30-10:00 h) and dinner (19:00-20:00). In all 3 groups, leptin and insulin resistance was determined. In patients with DM2 leptin and insulin deficiency was revealed, which was confirmed by the presence of negative correlations between insulin concentration and energy consumption (r=-0.817, p<0.001) and carbohydrates intake (r=-0.299, p<0.001), as well as between carbohydrate intake and leptin concentration (r=-0.221, p<0.01) and HOMA-IR (r=-0.257, p<0.005). The duration of sleep averaged 7±1 h per day, and bedtime using artificial illumination, on average, varied in the range of 22:00-23:30, which can lead to circadian mismatch, with the progression of insulin resistance. The decrease in the amplitude of the BT circadian rhythm in patients with EDCM and T2DM, as well as the presence of an inverse correlation between BT and energy consumption (r=-0.531, p<0.0001) and fat intake (r=-0.533, p<0.0001), and a positive correlation between BT and protein consumption (r=0.533, p<0.0001), may indicate the involvement of melatonin in the development and progression of disorders of carbohydrate metabolism.
Conclusion. The most significant risk factors for the development of disorders of carbohydrate metabolism, accompanied by circadian dysfunction in the surveyed, include irrational distribution of the energy value of food during the day, frequent meals, late breakfast and dinner; shifting the time of going to bed, shortening the duration of sleep, exposure to artificial lighting in the evening.
Factors limiting nutritional support for patients in chronic critical illness
Patients in chronic critical illness after brain injury may experience various conditions that limit nutritional support.
The aim of this work is to analyze the factors limiting or hindering the provision of nutritional support (in particular, enteral clinical nutrition) in patients in chronic critical illness after brain damage.
Material and methods. This study is a prospective observational cohort study. In the course of the study, 47 patients (27 men and 20 women, mean age 52±18.4 years) in a chronic critical illness who were undergoing rehabilitation after brain damage and who had certain limitations in the provision of nutritional support were evaluated. The duration of the patients’ stay in the intensive care unit was from 21 to 30 days. During hospitalization, adverse events and conditions were recorded in these patients, limiting the conduct of enteral clinical nutrition.
Results. Among the undesirable phenomena and conditions limiting enteral nutrition, diarrheal syndrome most often developed - in 41.7% of patients (associated with the use of antibiotics in 25.0% of the examined). The second group in terms of frequency - the development of surgical pathology (of various etiology) - in 31.7% of patients, which attracted special attention, taking into account the neurological and/or neurosurgical nature of the underlying disease. At the same time, the appearance of a high residual volume of the stomach against the background of an increase in hydrocephalus developed only in 5.0% of cases. More attention should be paid to patients who are in the most severe physical condition, since they have a high probability of the occurrence of several factors at once that limit the use of clinical nutrition - this category of the studied sample included 19.1% of patients.
Conclusion. Strict adherence to the technology of enteral nutrition can increase the efficiency of enteral nutrition in patients in chronic critical condition.
Low Fermentable Oligo-, Di- and Monosaccharides and Polyols (FODMAP) diet in the treatment of patients with irritable bowel syndrome: basic principles and methodology
Fermentable oligo-, di-, monosaccharides, and polyols (FODMAP) are a large class of small nondigestible carbohydrates, which are poorly absorbed in the small bowel. The microscopic size, high osmotic activity, and the higher fermentation of unabsorbed FODMAPs by colonic bacteria lead to bloating, abdominal pain, and flatulence in patients with irritable bowel syndrome. Therefore, low FODMAP diet appears to be promising treatment approach in the management of patients with irritable bowel syndrome (IBS). In this review, we analyzed available publications on efficacy and safety of low FODMAP diet in the treatment of IBS patients. Based on the current data we outlined basic principles and methodology of low FODMAP diet usage in clinical practice, and constructed the detailed list of low and high FODMAP products for designing a food regimen in patients with IBS.
Promising races of baker's yeast for the production of food ingredients enriched with selenium and chromium
It is known, that Saccharomycetes can accumulate mineral substances with targeted enrichment of the growth medium. However, the influence of the genetic affiliation of the culture and the technological factors of yeast strains, the composition of growth media on the efficiency of essential trace elements incorporation into the biomass and on the change of theirs intracellular components content have hardly been investigated.
In this regard, the aims of this work was to select promising races of yeast Saccharomyces cerevisiae, develop a biotechnological method for obtaining food ingredients enriched with selenium and chromium on their basis, and study their trace element composition.
Material and methods. Industrial strains of baker’s yeast (Saccharomyces cerevisiae) were used: RCAM 01137, Y-3439 and Y-581. Yeast were grown on malt wort (pH 4.6) with a dry matter content of 12% with the addition of mineral salts in stationary conditions at a temperature of 30 °C for 18 h, after which the yeast biomass was separated by centrifugation. A method for enriching yeast with trace elements has been selected, which consists in the process of culturing cells on malt growth media containing chromium chloride or selenium dioxide in various concentrations. The total protein content was determined by the Kjeldahl method, polysaccharides and ergosterol - by spectrofluorometric method, selenium - by fluorimetric method. The content of trace elements in yeast biomass enriched with chromium was studied by mass spectrometric method with inductively coupled plasma.
Results. It was shown that the highest specific growth rate was demonstrated by the yeast strains RCAM 01137 and Y-3439, and the highest level of maltase activity was in the Y-581 strain. It was found that the amount of biomass after cultivation of the yeast S. cerevisiae RCAM 01137 and Y-3439 was 6.00 и 5.42 g/100 cm3, respectively. It was noted, that the yeast S. cerevisiae Y-581 had capability of high synthesis of ergosterol (1.08±0.04%), the level of which was 2 fold higher than other strains. S. cerevisiae RCAM 01137 yeast showed the greatest ability to selenium enrichment, its content in biomass increased 137 fold and amounted to 2740 pg% when cultivated on a medium containing 800 pg/dm3. S. cerevisiae Y-581 yeast strain showed the highest capability to chromium sorption. The chromium concentration in its biomass was 8340 pg% in case of cultivating on a medium containing 750 pg/dm3. The usage of about 2.7 g of selenium enriched yeast biomass, or 1.0 g chromium enriched one, satisfies the daily requirement for these trace elements.
Conclusion. Cultivation of S. cerevisiae cells on growth media containing trace elements makes it possible to obtain yeast biomass samples that can be used to obtain food ingredients for creating food products that contribute to the maintaining human health and improve the quality and duration of life.
Osteoprotective effect of bread enriched with protein, dietary fiber, calcium, iron and iodine in hypoestrogen-induced osteoporosis among rats
The search for new strategies for the prevention and control of osteoporosis is an urgent task. Functional foodstuffs and their components are of particular interest in this regard.
The aim was to study the effect of bread enriched with protein, dietary fiber, calcium, iron and iodine on the state of the bone tissue of rats in a model of postmenopausal osteoporosis.
Material and methods. The experiment was performed on sexually mature female Wistar rats divided into groups: K - control (sham-operated rats, not ovariectomized); О30 - osteoporosis model (animals were sacrificed 30 days after ovariectomy); groups O120 and О120+ - a model of osteoporosis (rats were sacrificed 120 days after ovariectomy). All animals were fed a standard vivary diet. For rats of the О120+ group, from the 40th to the 120th day, enriched bread was included in the diet in an amount of 6 g per 100 g of body weight per day. The bread was fortified with protein (whey protein, blood plasma proteins from farm animals), dietary fiber, calcium (eggshell), iron (purified hemoglobin) and iodized whey protein. Animals of groups K and O120 received unfortified bread in the same amount. Blood levels of total calcium (by colorimetric method), gonadotropins, testosterone, and estradiol (by enzyme-linked immunosorbent assay) were analyzed. Microtomographic evaluation of the architecture and mineral density of the trabecular part of the femur and lumbar vertebrae was performed. Histomorphological analysis of the uterus and femur of animals was performed.
Results and discussion. In animals of the О120+ group, in comparison with the O120 sample, there was a decrease in blood testosterone and a marked compensatory release of follicle-stimulating hormone, while no changes were detected in the concentration of estradiol and the state of the uterus atrophied against the background of ovariectomy. There was an increase in the trabecular mineral density of the femur and lumbar vertebrae. The proportion of bone trabeculae in the total volume of the femoral metaphysis (BV/TV) in animals of the О120+ sample was 12.5±0.66% compared to 10.4±0.52% in the O120 group. The values of the structural model index (SMI) reflecting the loss of bone strength and the trabecularity coefficient (TbPf) in О120+ rats (1.44±0.07 and 5.96±0.29 1/mm) were significantly lower than these parameters in the O120 group (1.74±0.08; 9.13±0.46 1/mm, р<0.05). The micro-architectural structure of the femur in the O120+ group of rats was close to that of the O20 sample, which serves as a model of the early stage of osteoporosis (SMI 1.42±0.07; TbPf 5.55±0.28 1/mm). The percentage of bone resorption perimeter and the number of osteoclasts in the О120+ femoral trabeculae were lower than in the O120 group. In the O120+group, active osteoblasts were observed in a significant part of the resorption cavities. Cell differentiation more was observed in the osteogenic direction than in the adipogenic direction.
Conclusion. Bread enriched with protein, fiber, calcium, iron and iodine, effectively weakens osteoporosis induced by ovariectomy in rats. Its inclusion in the diet may be beneficial for the prevention and treatment of systemic postmenopausal osteoporosis.
Justification of the need to normalize vitamin D status for immunoprophylaxis
Currently, there is an increase in the resistance of microorganisms to the available arsenal of antimicrobial drugs, which makes it necessary to maintain and stimulate the body’s own immune-protective properties. The main extraskeletal effect of vitamin D activity is associated with the homeostasis of the immune system. The role of vitamin D in reducing the risk of infection with infectious agents has been studied for a long time. Literature search on the effective use of vitamin D for immunoprophylaxis was carried out in Scopus, Web of Science, PubMed, clinicaltrials.gov databases over the past 10 years for related keywords: vitamin D, immunoprophylaxis. Vitamin D stimulates the synthesis of antimicrobial peptides, cathelicidins and defensins, which exhibit broad-spectrum activity against viruses, bacteria and fungal infections; reduces the concentration of pro-inflammatory cytokines; increases the concentration of anti-inflammatory cytokines. Vitamin D is also involved in cell differentiation, maturation and proliferation of immune cells. The article presents the literature review in order to justify additional intake of vitamin D in case of diagnosis of its deficiency and insufficiency for the purpose of immunoprophylaxis in children and adults, especially in risk groups (elderly age, pregnant women, patients with chronic diseases of respiratory, endocrine and urinary systems, gastrointestinal tract, and infectious diseases). Inclusion of vitamin D in the diet as a dietary supplement, as well as fortification of products with it, can be an effective measure to reduce the risk of both morbidity and mortality, especially during the period of quarantine measures.
The impact of bilberry fruits polyphenols, sorbed on buckwheat flour, on the induced disorders of carbohydrate metabolism of male C57BL/6c mice
The hypoglycemic properties of polyphenolic compounds of plant origin are confirmed by the results of numerous preclinical and clinical studies. However, the biological effects of these compounds are limited by their low bioavailability. This makes it urgent to develop methods for its increasing due to new methods of entering polyphenols into the organism, for example, by extracting them from natural sources in the form of extracts and concentrating extracts on food polymer matrices for subsequent use as a functional food ingredient (FFI).
The aim of this study was to evaluate in vivo the possible effect of consumption of the obtained FFI in the form of a food matrix -buckwheat flour enriched with bilberry polyphenols - on carbohydrate metabolism disorders induced by a high-fat diet with a high content of easily digestible carbohydrates (sucrose) and anxiety level of male C57Bl/6c mice.
Material and methods. The food matrix was obtained by sorption of the bilberry fruits polyphenol extract on buckwheat flour. The total polyphenol content in the composition of food matrix was 8.9±0.7 mg-eq gallic acid/g flour. Total anthocyanin content in the composition of food matrix was 4.6±0.1 mg/g flour. The experiment was conducted for 150 days using 48 male C57Bl/6c mice (weaners). The animals were divided into 3 groups: the control group K1 (n=16, the mice received a standard semi-synthetic diet (22.5% protein, 10% fat, 58% carbohydrates as starch, 362 kcal/100 g), the control group K2 (n=14) and the experimental group G3 (n=18). Disorders of carbohydrate and lipid metabolism in animals of groups K2 and G3 were modeled by feeding an iso-nitrogenous high-fat diet with a high content of easily digestible carbohydrates (HFHC-diet: 22.5% protein, 30% fat, 18% carbohydrates in the form of starch, 20% sucrose, 493 kcal/100 g). FFI, a food matrix in the amount of 6.6 g/100 g of feed, was introduced into the diet of animals of the experimental group G3, which corresponded to the amount of polyphenols equal to 58.7 mg-eq gallic acid/100 g of feed and the content of anthocyanins 30.4 mg/100 g of feed. Once every three weeks, the level of glucose in the blood of animals was monitored. On days 60 and 114 of the experiment, animals were tested on an elevated plus maze. Animals were decapitated under light ether anesthesia at the end of experiment. The content of glycated hemoglobin was determined in the blood.
Results and discussion. Animals of both groups treated with HFHC-diet consumed significantly less feed compared with animals of the control group K1 (2.91±0.05 g/day per mouse). Moreover, animals of the experimental group G3 consumed significantly more food (2.51±0.04 g/day per mouse) compared with animals of the control group K2 (2.36±0.04 g/day per mouse). In contrast, the energy consumption of animals of both groups fed HFHC-diet was significantly higher compared to the K1 group (10.5±0.2 kcal/ day per mouse). Energy consumption by animals of group G3 (12.3±0.2 kcal/day per mouse) was significantly higher compared to animals of the control group K2 (11.5±0.2 kcal/day per mouse). The data obtained indicate that the consumption of FFI in the form of polyphenols adsorbed on the food matrix can contribute to increased appetite in animals treated with the high-fat diet. The results of the Elevated Plus Maze test indicated the absence of the effect of polyphenols in the composition of the food matrix on the anxiety level of animals. Starting from day 42 until the end of the experiment, the glucose level in animals of group G3 was significantly lower than the corresponding indicator for animals of the control group K2.
Conclusion. In accordance with the results obtained, further studies of the safety and clinical efficacy of including the developed FFI in the form of a food matrix with polyphenols into the composition of specialized foods for the prevention of carbohydrate metabolism disorders are advisable.
The development and experimental evaluation of the effectiveness of a new specialized food based on dried mare’s milk during exercise
The development and implementation of effective means to improve performance, endurance, rapid recovery of the body afterphysical exertion and, ultimately, improve athletic performance are still relevant.
The aim of the work was to develop a new specialized product based on dry mare’s milk, as well as to evaluate its effectiveness on an experimental model of physical activity.
Material and methods. A specialized product has been developed, including powdered mare’s milk, skimmed cow’s milk, vegetable cream, crushed sea buckthorn fruits, wheat germ, vitamins A, E, C, PP, folic acid, mineral substances (selenium, magnesium, zinc, iron), inulin, dry bacterial starter culture (Lactobacillus acidophilus, Streptococcus lactis, Bifidobacterium bifidum in a 1:1:1 ratio) and fucoidan. Experimental studies were carried out on 70 white male Wistar rats with an initial body weight of 207-226 g. Animals were fed complete semi-synthetic diet with free access to food and water. Animals of the experimental group additionally received 10 g of a specialized product daily. The control group of animals additionally received glucose in an amount corresponding to the calorie content of 10 g of the specialized product (45 kcal). The animals were subjected to physical exertion - forced swimming until they were completely tired. The swimming test was carried out every seven days during the 21-day experimental period with a load of 10% of the animal’s body weight. In hemolysates of erythrocytes, liver microsomes, and in the mitochondrial fraction of the femoral muscle, the activity of catalase and superoxide dismutase was assessed using kits, the concentration of malondialdehyde (MDA) and diene conjugates was determined by spectrophotometry. The level of lactic and pyruvic acids in the blood serum and femoral muscle of rats was assessed by spectrophotometry. The liver and heart were histologically examined.
Results. Feeding animals the specialized protein product for 21 days resulted in a statistically significant increase in endurance, as evidenced by data on the time of swimming with a load. So, in the experimental group, in comparison with the initial data, the swimming time increased by 223%. In the control group, the time of swimming with a load increased in comparison with the initial data by only 71.4%, which was 3.1 fold lower than the values in the experimental group. The time of swimming with a load of animals from both groups did not change statistically significantly in the next 7 days offeeding exclusively semi-synthetic diet. The consumption of the specialized product was accompanied by a positive trend in the change in the antioxidant status indicators. Thus, in the membranes of erythrocytes, there was a decrease in the concentration of malondialdehyde by 55.2% and an increase in the activity of catalase and superoxide dismutase by 19.6 and 37.9%, respectively, compared with data in the control group. In the microsomal fraction of the liver, the level of MDA decreased by 40.0% and catalase activity increased by 59.6%. In the mitochondrial fraction of the femoral muscle, a decrease in the level of MDA and diene conjugates was noted, respectively, by 46.8 and 40.8%. In rats of the experimental group, the concentration of lactic acid in the blood serum was reduced by 40.6%, and in the femoral muscle - by 24.7% compared with animals of the control group. Histological studies of the hepatic and cardiac tissues confirmed positive changes in the structure of the studied organs.
Conclusion. The results obtained indicate a favorable effect of the protein mixture on the state of the antioxidant system, the general physiological state of rats, their endurance in relation to physical activity, which is largely associated with the set of food ingredients included in the composition, and, first of all, complete protein, vitamins-antioxidants (A, E, C), as well as energy sources, pre- and probiotics, minerals and trace elements, immune defense factors that favorably affect the state of the membranes of erythrocytes, myocytes and hepatocytes and increase not only the body’s endurance, but also its metabolic functions, which is confirmed by the data of biochemical and morphological studies.
Analysis of adequacy of actual nutrition for athletes at training camps
An increase in special performance in elite sports requires optimization of the metabolic parameters of the organism at all stages of the annual training cycle. In this regard, it is relevant to analyze the adequacy of the actual nutrition of athletes, taking into account the energy expenditures of training loads in different seasons of the year.
The aim of this study was to analyze the integral adequacy and balance of the main and essential components of the diet of athletes in different seasonal periods of the annual training cycle.
Material and methods. 20 highly qualified road cyclists (the average age 22.4±0.7 years) have been examined. Individual energy expenditures of the subjects has been determined, the actual nutrition of athletes was studied by the method of 24-hour dietary recall. In different seasons of the year, in the conditions of training camps, 1540 dietary rations of athletes have been analyzed over 5 years. The study of the energy balance and the adequacy of the actual nutrition was carried out using the developed author’s automated system “FP Diet”.
Results. The average daily energy consumption of cyclists at different stages of the annual training cycle ranged from 4503±69 to 4646±88 kcal, which indicates that athletes belong to one of the energy-intensive sports. The calorie intake practically satisfied the average daily energy expenditures, however, the low values of the integral indicator of adequacy (43.2% for the winter-spring season and 60.0% for the summer-autumn season) indicated significant imbalances in the actual diet for the main and essential nutritients, especially noticeable in the groups of vitamins and fatty acids. Against the background of insufficient consumption of vegetable oils, which causes a lack of monounsaturated fatty acids in the diet, an excessive consumption of saturated fatty acids, a deficiency of vitamins B1 and B2, a lack of vitamin C in the winter-spring period, as well as calcium and magnesium deficit have been revealed.
Conclusion. The qualitative characteristics of the diet of cyclists in different seasons of the annual training session does not meet the physiological needs of the organism. Optimization of athletes’ nutrition in terms of calorie content and chemical composition must be carried out taking into account the nature and methods of the training cycle, which have significant differences in the energy orientation of the loads and daily energy expenditures.
Alkaline transesterification CG-MS/MS method of monochlorpropanediol and glycidyl esters’ determination in some edible fats, oils and fat blends on Russian market
Monochlorpropanediol fatty acid esters (MCPDE) andglycidyl fatty acid esters (GE) are mainly considered to be processing contaminants and their concentration can rise during high temperature refining and deodorization of edible oils. Free forms formed during digestive hydrolysis of esters such as 3-monochloropropane-1,2-diol (3-MCPD), 2-MCPD and glycidol can provoke a negative effect on human health. Therefore the quantitative determination of MCPDE and GE in edible oils, fats and fat blends is needed.
The aim - this manuscript deals with MCPDE and GE concentration measured as free 3-MCPD, 2-MCPD and glycidol in different edible oils, fats and fat blends of Russian market.
Material and methods. 55 edible oil and fat samples sold on Russian market including refined and non-refined oils and fat blends such as spreads, dairy fat replacers, and margarines have been analyzed. Slow alkaline transesterification method with GC-MS/MS was used.
Results. According to the data obtained, the highest concentrations of the contaminants were detected in fat blends: <0.10-5.03 mg/kg for 3-MCPD, <0.10-2.50 mg/kg for 2-MCPD and 0.15-11.17 mg/kg for glycidol. In palm oils and its fractions concentration of 3-MCPD was <0.10-6.61 mg/kg, 2-MCPD - <0.10-2.69 mg/kg and glycidol - <0.10-6.29 mg/kg. The content of glycidol in sunflower oils fluctuated in the range <0.10-1.19 mg/kg, 3-MCPD was <0.10-2.47 mg/kg, and 2-MCPD <0.10-0.67 mg/kg. Non-refined edible oils and olive oils had no or little MCPDE or GE.
Conclusion. In this work we indicate high importance of monitoring MCPDE and GE in edible oils and fats both as ready-to-eat products and as ingredients prior to the Russian market release. There is strong need in mitigation of these process contaminants during fat blends manufacturing.
Development and validation of methodology of quantitative determination of sibutramine in dietary supplements by high performance liquid chromatography
Sibutramine is a highly effective drug for the treatment of obesity. In this regard, unscrupulous manufacturers can add sibutramine as a biologically active synthetic substance prohibited for use in the composition of dietary supplements. Thus, the problem associated with the illegal circulation of such dietary supplements is especially actual, given the scale of the sale of these products. The development and validation of methods for the determination of sibutramine in dietary supplements for slimming (anorexigenic action) for the purpose of quality control in order to ensure the quality of dietary supplements when introduced into civil circulation at customs and on the market.
The aim of the study - to develop a method for the quantitative determination of sibutramin in dietary supplements for weight loss by high performance liquid chromatography (HPLC) and to validate it.
Material and methods. For the quantitative determination of sibutramine in dietary supplements, we used an Agilent 1100 high performance liquid chromatograph with a UV-detector. The stationary phase was a chromatographic column C18 NU CLEOSIL 4.6x 150 mm, particle size 5 pm. The mobile phase contained 0.05 M formate buffer pH 4.0 and acetonitrile in a ratio of 40:60 (by volume).
Results and discussion. A methodology has been developed for the determination of sibutramine in dietary supplements for weight loss, which makes it possible to control the quality of dietary supplements. Based on the obtained chromatograms, the specificity was determined; the plant components did not influence the determination of sibutramine in model mixtures. The suitability of the chromatographic system was determined: the retention factor of the compound - 2.222 (more than 2.0), N - 5776 theoretical plates (more than 5000), Tpeak of sibutramine - 0.939 (not more than 1.5). Within the analytical area of the linearity method: R2=0.9993 (over 0.9950). ε=0.46% (does not exceed 1.5%), the confidence interval includes the value of 100%, the calculated value of the Student’s criterion tcalc (2.47) was less than the tabular ttable (2.80), which proved the correctness of the methodology. The precision of the results was determined by the obtained RSD value, which was 0.91% (less than 1%). Limit of detection (LOD) and limit of quantification (LOQ) took values of 0.1 and 1.0%, respectively. The range of measured concentrations was 0.01-20.0 mg/g.
Conclusion. As a result of the studies, the method for sibutramine determination in dietary supplements with anorexigenic action was tested and can be used in quality control of dietary supplements.