Вопросы питания № 6 2022

Problems of Nutrition

scientific and practical journal

Included in the List of the leading peer-reviewed journals and publications recommended by the Higher Attestation Commission (HAC) of the Ministry of Education and Science of the Russian Federation for publication of the results of theses for the degree of candidate or doctor of science.


Content
6 . 2022
Reviews

Specialized vitamin-mineral supplements for persons in extreme conditions

Annotation

Monitoring the actual nutrition of various groups of the population of the Russian Federation indicates the presence of pronounced deficiencies of essential micronutrients, and above all vitamins and biologically active compounds. Deficiency of many micronutrients is a risk factor for the development of a number of conditions (anxiety, depression, etc.) and non-communicable diseases (cardiovascular, cognitive and neuromuscular disorders). It reduces the effectiveness of the treatment of injuries and wounds, and also leads to a negative effect on the antioxidant protection of the body and a more pronounced response to stress. To prevent long-term consequences, the population is primarily provided with psychological assistance, not always paying due attention to healthy nutrition.

The aim of the research was to substantiate and develop vitamin-mineral supplements (VMS) for special purposes to restore impaired functions in various population groups in extreme situations, including those located in the zones of a special military operation.

Material and methods. A review of the literature on the problem in recent years was carried out using the databases of the RSCI, Google Scholar, ResearchGate, PubMed by the keywords “B vitamins”, “vitamin-mineral supplement”, “military personnel”, “mood”, “efficiency”, “depression”, “refugees”, «multivitamin», «conflict», “efficiency”.

Results. In an emergency situation, under conditions of high physiological (physical and neuropsychiatric) stress, the requirements in micronutrients increase. An inverse association between micronutrient status and the development of symptoms of depression, sleep disturbance has been found. The analysis of the data on the administration of VMS with different composition in the nutrition of the population and law enforcement officers showed the effectiveness of its intake for all persons in the zone of military conflicts. At the same time, VMS should contain a complete set of vitamins, in doses for B vitamins 200–300% of the recommended daily intake (RDI), vitamin D and other vitamins in a dose of 100%, magnesium, zinc, iodine, iron – in doses up to 50% of RDI. The administration of such VMS for 1–6 months provides an increase in blood serum vitamin level and antioxidant activity, leads to an improvement in functional adaptation and military professional performance, increases self-esteem of health, reduces symptoms of stress and anxiety, improves the mood.

Conclusion. The expediency of including VMS for special purposes in the nutrition of both military personnel and the entire population in the zone of military conflict has been proved. Enrichment of the diet with micronutrients is a reliable non-drug prevention of health disorders caused by stress in emergency.

Amaranth, quinoa and buckwheat grain products: role in human nutrition and maintenance of the intestinal microbiome

Annotation

Pseudocereals such as amaranth, quinoa and buckwheat have been used as food since ancient times and in recent years there has been an increasing focus on their ability to have positive health effects. Moreover, some of the functional effects of pseudocereals could be mediated by effects on the gut microbiota.

The review aims to assess the features of the chemical composition of amaranth, quinoa and buckwheat grain that determine their potential for maintaining the optimal composition of the intestinal microbiota, as well as to analyze the results of published studies evaluating the effects of pseudocereals on the intestinal microbiota.

Material and methods. Scopus, Web of Science, PubMed, RSCI databases, and food composition databases were used for collection and analysis of scientific information.

Results. The research presents an overview of the chemical composition of amaranth, quinoa and buckwheat grain regarding their influence on the intestinal microbiota. Compared to traditional cereals, the grain of these pseudocereals has high content of soluble dietary fiber, which could have a prebiotic effect in the gut stimulating the growth of protective microbiota populations and increasing production of short-chain fatty acids (SСFA), which play a crucial role in maintaining gut homeostasis and health in general. Amaranth, quinoa and buckwheat grain, as well as some grain fractions such as proteins and polysaccharides, may have positive effects on the gut microbiota, and the biologically active substances metabolized by them have a positive effect on the body’s metabolism. The results of in vitro (by cultivation using model media) and in vivo experiments indicate that the introduction of various grain fractions of pseudocereals into the diet contributes to an increase in the content of SCFA, in alpha microbiota diversity indices, and also prevents the development of dysbiotic disorders caused by a high-fat diet.

Conclusion. Pseudocereals’ grain is promising raw material for the development of products that can have a positive effect on the intestinal microbiota.

Arthrospira platensis phycocyanins: a perspective for use in foods for special dietary uses (brief review)

Annotation

Biomass of Arthrospira platensis has a long history of consumption as a source of protein, a number of micronutrients and minor biologically active compounds. Specific organoleptic properties of Arthrospira platensis biomass (pronounced bitter taste) limit its use as a source of phycocyanins. The developed modern methods of phycocyanin extraction from A. platensis biomass make it possible to obtain concentrates with improved sensory characteristics destined for the inclusion in foods for special dietary uses.

The aim of this brief review was to analyze the results of the studies on the assessment of the biological activity of phycocyanin extracted from the Arthrospira platensis biomass, substantiating the prospects of using their concentrates for inclusion in foods for various dietary purposes.

Material and methods. The PubMed Web Database, including MEDLINE article database, covering about 75% of the world’s medical publications, was used for the main search for the literature. In addition, Scopus and Web of Science databases were used. Search depth – 15 years. Search keywords: Arthrospira platensis, phycocyanins, safety, antioxidant activity, immunomodulatory properties.

Results and discussion. C-phycocyanin and allophycocyanin are complexes of proteins with the pigment phycocyanobilin, their total content is about 50% of the content of all proteins in the A. platensis biomass. A significant number of toxicological studies indicate that there are no risks to human health when using phycocyanin-containing extracts of A. platensis. Evidence of the antioxidant effect of phycocyanins extracted from A. platensis biomass, their anti-inflammatory activity, immunomodulatory properties, was obtained experimentally in vitro and in vivo, as well as in clinical studies.

Conclusion. Toxicological studies and experimental in vivo tests have shown the safe and effective use of Arthrospira platensis biomass extracts with a high content of phycocyanins as an additional means of dietary prevention and diet therapy. These data indicate the prospects for conducting additional studies on the possibility of including phycocyanin concentrates in specialized foods for various purposes.

Physiology and biochemistry nutrition

Influence of multiple insufficiency of vitamin D and B group vitamins, calcium and magnesium in the diet of rats on micronutrient sufficiency and plasma biochemical indicators

Annotation

The lack of vitamins D, B group, calcium and magnesium is common for the diet of the Russian population. It has been previously demonstrated that that the elimination of B vitamin deficiency is a necessary condition for the implementation of vitamin D biological functions.

The aim of the research was to assess the effect of a combined deficiency of vitamins D and B group, calcium and magnesium in the diet of rats on biomarkers of micronutrient sufficiency and plasma biochemical indicators.

Material amd methods. Male Wistar rats with an initial body weight of 66±1 g were randomly assigned to one of five groups. The rats of the 1st group (Control) were fed a standard semi-synthetic diet (SD) for 28 days. The combined deficit of vitamins D and B group, calcium and magnesium in rats of four experimental groups was caused by a 5-fold decrease in their content in the vitamin mixture and 2-fold decrease in their content in mineral mixture of the SD for 23 days. Over the next 5 days, the rats of 2nd group (+В+D+Ca+Mg) were fed a diet replenished for all missing vitamins and minerals, the rats of 3rd group (-В+D+Ca+Mg) were fed a diet with continued deficiency of B group vitamins, the rats of the 4th group (+В+D-Ca-Mg) were fed a diet with continued lack of calcium and magnesium, the diet of the 5th group (-B-D-Ca-Mg) was not replenished. Vitamins B1 and B2 in lyophilized liver and brain and urine, riboflavin in plasma and 4-pyridoxic acid in urine were determined by fluorimetric methods, 25(OH)D in plasma was determined by ELISA, the level of vitamins A and E in blood plasma and lyophilized liver, of vitamin E in whole brain – by HPLC. Biochemical parameters of blood plasma were determined using a biochemical analyzer.

Results. In rats of the 5th group (-B-D-Ca-Mg), there were 3.4-fold increase (p<0.05) in iron plasma level, 1.7-fold elevation (p<0.10) in alkaline phosphatase activity, and 1.8-fold decrease (p<0.05) in alanine aminotransferase (ALT) activity on the background of the increase in α-tocopherol blood plasma level by 26.7% (p<0.05) and liver content by 2.0 fold (p<0.05) relative to the indicators in animals who hadn’t passed the deficiency of micronutrients (Control) and / or from the 2nd group (+B+D+Ca+Mg). The lack of B group vitamins in the diet, which persisted during the correction of vitamin D, calcium and magnesium deficiency in rats of the 3rd group (-B+D+Ca+Mg), inhibited the recovery of diagnostically significant biochemical parameters of blood plasma (namely, an increased level of glucose, iron, triglycerides, cholesterol, α-tocopherol, increased alkaline phosphatase activity and reduced ALT activity) to the level in animals of the control group and/or rats fed the diet replenished for all missing micronutrients (+B+D+Ca+Mg).

Conclusion. Combined deficiency of several micronutrients led to changes in biochemical blood parameters. Reduced intake of calcium and magnesium during the correction of the lack of vitamins D and B group in the diet can have a negative impact on vitamin B2 status. Even under normal dietary vitamin E intake the combined deficiency of several other micronutrients affected the metabolism of this vitamin (increased levels of vitamin E in the liver and blood plasma of animals). Chronic combined alimentary deficit of B vitamins, calcium and magnesium, which is characteristic in the diet of the Russian population, reduces vitamin D bioavailability, which justifies the expediency of using vitamin-mineral complexes.

Аllergic sensitization in children with atopic dermatitis in the first 2 years of life according to the results of skin tests

Annotation

Atopic dermatitis (AD) is associated with food allergies (FA), which frequency and structure varies from region.

The objective of the research was to determine the structure of FA in children (<2 years) with AD and to analyze age-specific sensitization.

Methods. 79 children with AD aged 2–24 months were examined (Russia, Moscow). Skin prick tests (SPT) with food allergens were used to determine sensitization, if necessary additional SPT with aeroallergens were performed.

Results. 51.9% of patients had hypersensitivity to at least 1 allergen. Positive SPT for egg were detected in 38.0%, cow’s milk – in 27.8%, fish – in 10.1%. Allergy to fish occurred predominantly in the 2nd year of life (35.0% vs 4.8, p=0.02). Soy, peanuts, and nuts were detected in less than 5% of patients. At 2–6 months of age, sensitization was found in 36.4%, and after 6 months in 57.9% (p=0.08). In the group with FA before 6 months of age (n=8), 7 patients were sensitized to egg and 6 to milk. The prevalence of milk and egg allergy did not differ between exclusively breastfed and formula-fed children. Hypersensitivity to allergens was found in 4 of 10 breastfeeding patients, for compared to 3 of 11 exclusive formula-feeding patients (p=0.66). Acute allergic reactions were reported in 6.3% of patients with AD, which was 12.2% of children with FA. Triggers were egg (n=5) and fish (n=4). Anaphylaxis did not occur until 6 months of age. The frequency of severe reactions was about the same in children 1st and 2nd years of age (p=0.64). SPT urticaria size, defined in points (max=4), did not differ between children 2–24 months of age. Egg and nut allergens showed the maximum skin reaction: medians were 3 [2; 4] and 1.5 [0.75; 2.5] points. Milk allergens caused significantly less reaction compared with egg (p<0.01). These differences were absent when comparing reactions to individual milk serum fraction proteins and reactions to egg. Hypersensitivity to non-food allergens was found in 41.5% of children with FA (21.5% of children with AD), mainly sensitization to cat epithelium, birch, house dust and dog epithelium was detected.

Conclusion. Sensitization to milk proteins and eggs is the leading since 2 months of age, without differences in relation to the age of the infant and the type of feeding. In all cases of moderate AD, SCT is applicable in children 0–2 years of age, with practically no age restrictions.

The study of the effect of mono- and polymalt extracts on the psycho-physiological functions of outbred rats in an experiment with course consumption

Annotation

The search for natural ingredients that have a certain nutritional value and contribute to the preservation of human health is a very urgent task.

The goal of this research was to study the effect of three viscous extracts – two polymalt and one malt extract, on the psycho-physiological functions of animals in an experiment with prolonged consumption.

Material and methods. The study was conducted on white mongrel male rats weighing 110–130 g, divided into 4 groups of 13 individuals. The 1st group (control) received standard granulated feed without extracts, the 2nd group – the feed with a polymalt grain extract from barley, hulless oats and wheat, the 3rd group – the feed with a polymalt grain extract from barley, hulless oats and rye, the 4th group – the feed with a malt extract from barley grain, in a dose of 2.1 g/kg of body weight. The consumption of the studied extracts in all groups of animals lasted 21 days. The animals were weighed before and after the consumption period and tested using the “Open field” test (research and motor activity were recorded), the «Rotating Rod» test (study of locomotor reactions), «Forced Swimming» (study of induced depression).

Results. The addition of malt and polymalt extracts to the diet of the experimental animals had a beneficial effect on them: the duration of fading as an indicator of depression during swimming test in all experimental rats decreased by 31.4–37.8% with varying degrees of statistical significance. At the same time, a monomalt extract from barley grain and a polymalt extract from grain of barley, naked oats, and rye had a more positive effect on the condition of the animals in the experiment: in the “Rotating Rod” test, the retention time of animals as an indicator of endurance increased by 26.0–27.1%; in the «Open Field» test, motor and exploratory activity increased and the time of passive behavior decreased by 35.0–37.4%.

Conclusion. The development, production and research of malt extracts is a promising direction that requires the selection of initial grain components taking into account their chemical composition. It is possible to create general restorative supplements on the basis of extracts, as well as to introduce them into alcoholic beverages in order to reduce the toxicity of ethyl alcohol and preserve a number of physiological functions in the human body during alcohol consumption.

CHEMICAL COMPOSITION OF FOODSTUFFS

Food allergy as a risk factor for acne

Annotation

Acne is a multifactorial disease in which genetic, hormonal, environmental and nutritional factors are involved. Data on the role of food and other etiological forms of allergy in the development of acne, as well as the nature of the sensitization spectrum, are extremely scarce, which makes the study relevant.

The purpose of the study was to analyze the features of the spectrum of sensitization to food, pollen, fungal allergens in patients with acne and establish the role of food allergy in the development of the pathology.

Material and methods. The study included patients with papulo-pustular acne of moderate severity aged 11 to 46 years (n=57). All patients underwent a specific allergologic examination, including skin prick testing with food, pollen and fungal allergens (Allergopharma, Germany).

Results and discussion. The most significant food allergens in patients with acne were whole chicken egg, chicken egg protein and chicken meat (66.7, 61.4 and 52.9% respectively). Sensitization to barley and oat groats was noted in 50.0 and 47.9% of cases. Sensitization to cow’s milk protein and beef was determined in 43.9 and 44.2% of cases. Meadow and cereal grasses were the most common among pollen allergens: 64.8 and 62.5% of cases, respectively. Among fungal allergens, a high frequency in the occurrence of sensitization to Alternaria alternata was revealed (67.9%). A positive clinical effect in the form of regression of skin inflammatory manifestations against the background of an elimination diet was noted in 71.9% of cases.

Conclusion. The conducted study, based on the established high frequency of sensitization to food allergens in combination with the positive effect of elimination, taking into account the presence of common antigenic determinants, allows us to make an assumption about the role of food allergy as a risk factor for acne.

Hygiene of nutrition

Effect of ionizing radiation on microbiological safety and activity of antioxidant enzymes in minced meat

Annotation

A number of studies have shown the effectiveness of meat irradiation at doses of 2–6 kGy to extend its shelf life when stored in vacuum packaging. It is known that the radiation treatment of meat can lead to a decrease in the content of natural antioxidants. Furthermore, the intensity of oxidative processes is significantly higher in meat products with a high fat content (20% or more). At the same time, the optimal modes of minced meat irradiation, which make it possible to ensure safety for the population and to increase the shelf life, have not yet been established.

The purpose of the research was to study the effect of various doses of ionizing radiation on the content of aerobic, facultative anaerobic microorganisms and radiolysis products, and the activity of antioxidant enzymes in chilled minced meat during storage.

Material and methods. The object of the study was minced meat, consisting of beef and pork (1 : 1) with 20% mass fraction of fat. The experimental samples were irradiated on an electron accelerator UELR-10-15-S-60-1 with an electron energy of 5–10 MeV at doses of 2, 2.5 and 3 kGy. The control sample of minced meat was not subjected to radiation treatment. Determination of the total count of mesophilic aerobic and facultative anaerobic microorganisms (QMAFAnM) (CFU/kg) in control and experimental samples was determined on days 0, 7, 15 and 22. Methods for evaluating antioxidant activity included spectrophotometric determining the content of active radiolysis products that react with 2-thiobarbituric acid (TBA-AP) according to the Brajet method, total antioxidant capacity (TAOC) and activity of antioxidant enzymes in minced meat: superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx).

Results. Radiation treatment of minced meat at a dose of 2.0 kGy provided a normalized level of QMAFAnM in chilled minced meat for 22 days. It has been established that the treatment of minced meat with ionizing radiation in doses of 2.0–3.0 kGy leads to a dose-dependent decrease in its TAOC and the activity of antioxidant enzymes (SOD, CAT, GPx), as well as to an increase in TBA-AP content (р<0,05).

Conclusion. The dose of ionizing radiation of 2.0 kGy helps to maintain the microbiological safety of minced meat for 22 days in terms of QMAFAnM with minimal changes in TAOC values, SOD, CAT and GPx activity and TBA-AP content.

Micronutrients in nutrition

The study of blood serum trace elements in comparison with the structural and functional characteristics of goiter and the carriage of antithyroid antibodies in some regions of Russia

Annotation

The study of the sufficiency with essential trace elements in the context of thyroid pathology is especially relevant, since the development and progression of thyroid diseases have various pathogenetic mechanisms, which largest proportion is provoked by insufficient intake of key trace elements, primarily iodine.

The aim of the research was obtaining primary data on the sufficiency with essential trace elements of the population in the some regions of the Russian Federation, comparing the data obtained with the prevalence of goiter and the carriage of antibodies to thyroid peroxidase (AT-TPO).

Material and methods. The Cross-Sectional Population Study was conducted in medical institutions of the Republics of Crimea, Republics of Tuva and Bryansk region (persons applied for outpatient consultations). The scope of the study was 387 people aged 18 to 65 years (the average age was 40±5 years). All of them underwent: collection of medical history, endocrinologist examination with palpation of the thyroid gland (TG), ultrasound examination of TG, blood sampling to assess the levels of thyroid-stimulating hormone (TSH), AT-TPO, iodine, selenium, zinc. Ultrasound of the TG was performed in the supine position using a portable ultrasound machine LOGIQe (China) with a multi-frequency linear probe 10–15 MHz. During the study, the volume of the thyroid gland, the presence of nodular formations and their characteristics according to the TIRADS classification, TG structure and its echogenicity were assessed. Iodine, selenium and zinc level were measured using tandem mass spectrometry with ionization in inductively coupled plasma (Agilent 8900 ICP-MS Triple Quad). TSH and Ab-TPO were determined by chemiluminescent immunoassay on the Architect i2000 automatic analyzer.

Results. All regions are comparable in terms of iodine availability, but differ in the severity of natural iodine deficiency. The median concentration of iodine in blood serum practically coincided in all three regions, amounting to 39.8 µg/l in the Republic of Crimea; 38.8 µg/l in the Republic of Tyva and 43.4 µg/l in the Bryansk region. Comparing these results with foreign data, as well as with our results on urinary iodine level, obtained by routine cerium-arsenite method, we can assume that iodine content in blood serum corresponded to the lower limit of the normal target values.

The median concentration of selenium in blood serum also practically coincided in all three regions, amounting to 68.2, 72.1 and 62.8 µg/l, respectively, and probably meets the criteria for optimality. The median serum concentration of zinc in Bryansk region residents corresponded to a deficiency (491.3 µg/l) and was significantly lower compared to the indicator in the Republics of Crimea and Tyva (1633.2 and 1667.6 µg/l, respectively, values above optimal). Among the examined, the proportion of people with AB-TPO carriership was 23.5% (Republic of Crimea – 20.9%, Republic of Tuva – 26.4%, Bryansk region – 20.7%), with impaired thyroid function – 9.6% (6.2% – hypothyroidism, 3.4% – thyrotoxicosis). The frequency of goiter varied from 10 to 13.8%. There were no significant differences in the frequency of occurrence, ultrasonic characteristics of goiter and thyroid nodules by regions.

Conclusion. However, the results obtained do not allow to unequivocally judge the absence of micronutrient deficiency in the population of the regions of the Russian Federation, since used the ICP-MS method requires the development of our own reference values of trace elements; in the absence of the latter, data from similar foreign studies were taken as standards. In addition, in further studies it will be important to take into account additional criteria for assessing trace element deficiency, for example, activity of superoxide dismutase and alkaline phosphatase as indirect markers of zinc deficiency, etc. Correlation between blood serum concentration of trace elements and the frequency and structural characteristics of goiter, the carriage of Ab-TPO, and dysfunction of the TG was not revealed.

Nutrition of sportsmеn

Determination of cobalt in plasma blood samples by the ICP-MS method after oral intake of dietary supplements containing low doses of cobalt

Annotation

Salts of inorganic cobalt (Со) prevent the degradation of the alpha subunit of the hypoxia-inducible factor (HIF), imitating the state of hypoxia in the body and increasing the production of the endogenous hormone erythropoietin (EPO), and are used as doping substances that increase blood oxygen capacity and endurance, which give competitive advantages in sports. Currently, a large number of dietary supplements, including Co-containing ones, are offered on free sale. Their uncontrolled intake can affect not only the professional career of athletes, but also their health, due to the fact that this trace element and its salts are the strongest inorganic poisons and carcinogens. Despite this, their availability on the pharmaceutical market, a noticeable effect of erythropoiesis stimulation and a convenient oral form of administration lead to the need for their detection in modern doping control.

The purpose of this research was to develop an approach to differentiate cobalt from vitamin B12, present in the body in its natural state, from the intake of cobalt salts by quantifying and comparing blood levels of vitamin B12 and total cobalt.

Methods. The study involved 9 healthy volunteers (women and men) aged 25 to 45 years, leading an active lifestyle. Three of them took 2500 μg/day of cobalamin for 20 days (comparison group), three – dietary supplement containing cobalt asparaginate (100 μg/day in terms of pure cobalt), and the rest - dietary supplements with cobalt sulfate heptahydrate (100 μg/day in terms of pure cobalt) (administration groups) at the same time after meals. Blood samples were taken at baseline and on days 5, 9, 14 and 20. The concentrations of total cobalt in blood plasma samples of volunteers were measured by inductively coupled plasma mass-spectrometry (ICP-MS), the levels of cobalamin were determined on a Cobas 6000 immunochemical analyzer using the Elecsys Vitamin B12 II Assay ELISA kits.

Results. It was found that oral intake of of cobalamin at a therapeutic dose significantly exceeding the recommended daily intake (3 μg), there was a regular slight increase in the blood concentration of total cobalt (1.1 times). At the same time intake of dietary supplements containing cobalt in the form of sulfate or asparaginate (about 100 μg per day in terms of pure cobalt) was accompanied by 4–6.7 fold increase in the concentration of total cobalt while unchanged vitamin B12 plasma concentration was observed. The detection of such changes can reliably indicate the use of prohibited salts and, of course, will be in demand for anti-doping control.

Conclusion. Long-term monitoring of vitamin B12 and total cobalt levels, similar to hematological module of the Athlete Biological Passport program, will unambiguously detect possible abuse of cobalt salts and can be an additional evidence of the presence of these doping substances to other analytical methods, such as a combination of liquid chromatography and ICP-MS (LC-ICP-MS).

Chemical composition of foodstuffs

Juices in a healthy diet: recommendations for consumption based on chemical composition data

Annotation

Juices from fruits and vegetables show a complex composition, they contain several hundred different substances. In addition to water and common metabolites such as carbohydrates, juices contain organic acids, minerals and trace elements, vitamins, polyphenolic and other biologically active compounds. Moreover, each type of juice is characterized by a unique set of natural compounds and is able to contribute to providing the human body with micronutrients. The study and analysis of the nutrient composition of commercially produced juices, which are currently the most consumed by the population, contributes to understanding the place of juices in healthy nutrition and is intended to contribute to the development of relevant recommendations for their use.

The purpose of the research was to evaluate their nutritional density and nutritional value based on the analysis of published data on the nutrient composition of juices, and then offer recommendations on the use of juices in healthy nutrition.

Material and methods. The analysis of nutrient profiles of ten popular types of juices presented on the market of the Russian Federation (apple, orange, grapefruit, grape, tomato, pomegranate, pineapple, carrot, cherry, peach) was carried out. Nutritional density indices (NDI) were calculated as the degree of satisfaction of a person’s need for a particular nutrient when filling the calorie value of the diet (2500 kcal) only with this product. The integral score characterizing the degree of the juice compliance with an optimally balanced daily diet, taking into account the energy content, which provides 5% of energy, was also calculated.

Results. NDI and the integral score of various types of juices show that juices have a high nutritional value and can make a significant contribution to the intake of some nutrients and bioactive compounds. The most important substances from juices are polyphenolic compounds (flavonoids, phenolic acids) and carotenoids (β-carotene, lycopene). All juices also contain significant level of potassium and magnesium, and they can serve a source of some vitamins and minerals (depending on the individual nutrient profile): citrus juices are the source of vitamin C and folates, pineapple – of manganese, vitamin C and B vitamins, apple – chromium, grape – molybdenum, iron and chromium, pomegranate – copper and tannins, cherry – iron, copper and pantothenic acid; vegetable juices, such as tomato and carrot juices, contain a wide range of essential micronutrients. Juices with pulp and juices without clarification can be a source of pectins and dietary fiber. Modeling of juice rotation in the diet shows that in this case, 75% of the nutrients (from 32 studied) will have a NDI≥1, i.e. provide a meaningful intake with juice.

Conclusion. The characteristic features for each type of juice regarding the content of vitamins, minerals and other biologically active compounds should be taken into account to assess the place of juices in healthy nutrition and develop modern recommendations for their consumption. Such recommendations include alternating different types of juices in the diet, as well as, if necessary, the choice of certain juices to include in the diet, depending on the individual’s nutritional needs.

Evaluation of the nanosize and stability of aqueous dispersions of iodine-containing conjugates based on carriers of plant origin, promising for iodine enrichment of foods

Annotation

The high proportion of iodine deficiency diseases in the structure of general morbidity determines the relevance of creating new non-toxic iodine-containing compounds and improving the processes of iodization of foods of mass consumption. In recent years, to solve this problem, a number of iodine-containing compounds based on natural polymers have been proposed, including pectin (iodine-pectin), casein (iodine-casein), inulin (iodine-inulin). It seems promising to create iodine-containing conjugates for food industry not only based on natural polymers, which are not individual compounds, but also based on low-molecular plant metabolites that have a high potential for correcting public health. The attention of researchers is attracted, in particular, by the glycosides of Stevia rebaudiana, which have positively proven themselves in the food industry for many years. Current trends in the development of industrial production of iodine-fortified products also include requirements for the compatibility of iodine-containing concentrates with food industry technologies, especially in the formation of time-stable micro-heterogeneous aqueous dispersions.

In connection with the above, the purpose of the research was to confirm the formation of an iodine conjugate with a low molecular weight metabolite of Stevia rebaudiana (glycoside rebaudioside A) by infrared (IR) spectroscopy; and to assess the resistance to sedimentation of its aqueous micro-heterogeneous dispersions (iodine-glycoside) comparatively with iodine compounds with natural plant polymeric carriers – pectin (iodine-pectin) and inulin (iodine-inulin) by the method of nanostructural analysis.

Material and methods. The IR spectra of the compounds were recorded on a Fourier spectrometer. Measurement of particle sizes in dispersions of iodine-containing substances was carried out on a laser analyzer, wave length 375 nm, in a quartz cuvette (7 ml) after 0, 2, 4, 6, 10, 24, 72 and 144 h. To prepare dispersions, a weighed portion of iodine-pectin (105 mg) was mixed in 100 cm3 of water (600 rpm) at a temperature of 35–40 °C for 60–70 min, weighed portions of iodine-glycoside (120 mg) and iodine-inulin (49.7 mg) were dissolved in 100 cm3 of water at room temperature (23 °C) for 3–4 min.

Results. An IR spectroscopy study of the interaction of iodine with rebaudioside A indicated the stabilization of molecular iodine by the functional groups of the glycoside, leading to the formation of a stable iodine-glycoside conjugate. Assessment of the aqueous dispersions of particles of this conjugate by nanostructural analysis showed that the substance iodine-glycoside formed a stable micro-heterogeneous dispersion with a particle diameter of about 300 nm, which didn’t undergo sedimentation during the entire observation period (6 days). Aqueous dispersions of the iodine-inulin with a particle size of ≤10 nm were comparable with true solutions and remained also stable throughout the entire observation period. Particles of the iodine-containing compound iodine-pectin formed moderately stable aquatic dispersed systems, the time of complete sedimentation of which was 6–10 h.

Conclusion. The study of the IR spectra of rebaudioside A and the synthesized sample iodine-glycoside made it possible to confirm the conclusion about the inclusion of iodine molecules in the structure of glycoside molecules. Micro-heterogeneous stable dispersions of this conjugate, as well as iodine-inulin substances, can be convenient concentrates for enriching milk with iodine. Rapid aggregation of particles of iodine-pectin substances in concentrates can prevent their uniform distribution in the target environment, which reduces the effectiveness of industrial technologies for iodine-fortified foods for the mass prevention of endemic goiter.

Food quality control and safety

Development and validation of methods for the quantitative determination of vitamins B1 and B2 in foods by high performance liquid chromatography with diode array detection

Annotation

The main sources of vitamins, which are essential substances, are mainly aliment products, foods for special dietary uses and dietary supplements. Therefore, the study of the native content of vitamins in aliment foods has always been of interest. For the chromatographic separation of vitamins, rather versatile C18 columns are used as a stationary phase, which allow one to obtain reliable results using UV detection for vitamin-enriched foods, dietary supplements and vitamin premixes. However, for unfortified foods, this stationary phase in a UV detection system does not give acceptable results.

The aim of the work was to develop a technique for the chromatographic separation of vitamins B1 and B2 in unfortified foods using a diode array detector.

Material and methods. To prepare samples of foods, concentrated acid hydrolysis (1.0 g of sample and 4 ml of 0.1 N hydrochloric acid) was carried out in a water bath for 30 min at a temperature of 95 °C, followed by enzymatic hydrolysis and degreasing. Further studies of the samples were carried out on an Agilent Technologies 1100 chromatographic system with diode array detection. For the determination of vitamin B1, a Poroshell 120 Hilic column 4.6×150 mm, grain size 2.7 μm was used. As eluent A, a 10 mM aqueous solution of ammonium acetate with 0.5% acetic acid was used, eluent B was acetonitrile (gradient elution: 0–2 min – 90% B, 8–12 min – 50% B, 14–18 min – 90% B). To determine vitamin B2, a C18 Poroshell column 4.6×250 mm, grain size 5 µm was used. As eluent A, a classical phosphate buffer with pH 2.5 was used, eluent B – acetonitrile (gradient elution: 0–5 min – 0% B, 5–15 min – 90% B, 15–22 min – 90% B, 22–24 min – 0% B, 24–27 min – 0% B). Vitamin B1 was detected at a wavelength of 270 nm, vitamin B2 at 450 nm. Under selected conditions, good retention and efficient separation of vitamins B1 (over 16,000 theoretical plates) and B2 (over 20,000 theoretical plates) was observed.

Results. It was demonstrated that the HPLC method with diode array detection can be used to quantify the native content of vitamins B1 and B2 in products with a complex food matrix. For the selective determination of these vitamins, a complex of chromatographic conditions is optimal: reverse-phase HPLC for vitamin B2 and hydrophilic interaction chromatography for vitamin B1. A suitable sample preparation of food products for the content of vitamins B1 and B2 under selected chromatographic conditions is concentrated acid-enzymatic hydrolysis. The limit of quantitation for vitamins B1 and B2 was 40 μg/100 g. Comparison of the enzymatic activity of amylorizin and thermostable α-amylase showed that during long-term hydrolysis for 16 hours (37 °С) with amylorizin, the degree of vitamin extraction was two fold higher than during hydrolysis (95 °С, 1 h) with α-amylase.

Conclusion. The selected conditions for determining the native content of vitamins B1 and B2 in unfortified and low-fortified foods can be used in practice, which has been proven through their successful validation and practical application on real samples of cereals.

Anniversary

Dmitriy B. Nikityuk (to the 60th anniversary of the birth)

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Gennady N. Shatrov (to the 85th anniversary of the birth)

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Index of articles

Index of articles published in the journal «Problems of nutrition» for 2022

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SCImago Journal & Country Rank
Scopus CiteScore
CHIEF EDITOR
CHIEF EDITOR
Viktor A. Tutelyan
Full Member of the Russian Academy of Sciences, Doctor of Medical Sciences, Professor, Scientific Director of the Federal Research Centre of Nutrition, Biotechnology and Food Safety (Moscow, Russia)
Вскрытие
Medicine today

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