Nanocellulose in the food industry and medicine: structure, production and application
Cellulose is the most abundant polymer in the biosphere and has many technical applications, including food production. The development of cellulose technology in the 21st century has led to the emergence of nanocellulose (NC), which has widely varying chemical and physical properties and, therefore, has fundamentally new areas of application in biomedicine and the food industry.
The aim of this work is to review the literature on the structure, sources, methods for obtaining nanocelluloses, including methods for their chemical modification, current and prospective applications in the food industry, packaging materials, biomedicine, etc.
Material and methods. For the analysis, sources were selected mainly for the period from 2014 to 2022, contained in the international databases PubMed, WoS and Scopus and meeting the requirements of scientific reliability and completeness.
Results. Among the main types of NC there can be identified nanofibrous cellulose (NFC), consisting of fibers longer than 500 nm and about 10–20 nm thick, and nanocrystalline cellulose (NCC) with particles 100–500 nm long and less than 100 nm in diameter. A special group of materials includes bacterial NC (BNC) produced by microorganisms and representing entangled coils or layers of cellulose fibers with a thickness of less than 100 nm. Significant changes in the physical, chemical and functional properties of NC can be achieved by its physical and chemical modification, which leads to a change in swelling, an increase in the mechanical strength and stability of hydrogels, and compatibility with synthetic polymers. NFC, NCC and BNC are offered as food ingredients for inclusion both in mass consumption products and in specialized foods for dietary and therapeutic uses, as well as in the so-called «functional products», for which manufacturers declare the ability to influence actively on the state of intestinal microflora and digestive function. In biomedical applications, of great interest is the biocompatibility of BNC with various cell types in combination with biodegradability, which makes it possible to create new types of materials for reconstructive surgery, effective and safe dressings. When used as packaging materials, NC products successfully compete with synthetic polymers without causing long-term environmental pollution. Factors hindering the introduction of NC products into practice are the gaps of knowledge of NC biological action, combined with the risks caused by possible residual amounts of chemicals and biochemical reagents, bacterial toxins, enzyme preparations and microorganisms-producers in the composition of NC.
Conclusion. There is an important task to develop a system for regulating NCs and products with its content, in accordance with the technical regulations of the Customs Union of the EAEU.
Hyperinsulinemia and age-related diseases: interrelations and approaches to treatment
Hyperinsulinemia is closely related with insulin resistance, that is the key mechanism for the progression of age-related diseases. A lot of aspects of hyperinsulinemia and interrelations between the mentioned conditions are very scarcely covered in Russian publications.
The present review is designed to fill the gaps in understanding the causal relationships between hyperinsulinemia, insulin resistance, age-related diseases and lifestyle factors.
Material and methods. Based on sources from PubMed and Google Scholar, using the keywords “hyperinsulinemia” + “chronic disease” OR “age-related disease” the authors analyzed the causes of hyperinsulinemia, the mechanisms of its influence on various aspects of insulin resistance, and the role of hyperinsulinemia in pathogenesis of a wide range of clinical syndromes and age-related diseases. Consideration of the effects that lifestyle factors produce on hyperinsulinemia opens up opportunities for its correction.
Results. The major causes of hyperinslinemia are improper diet and nutrition regime (frequent meals and excess of highly glycemic food, too short fasting window), along with other factors causing hyperreactivity of pancreatic beta-cells (fructose, systemic inflammation, oxidative stress, low vitamin D level, etc.). Hyperinsulinemia affects cellular energy balance (primarily, in liver, muscle, brain and adipose tissue); a major factor is suppression of 5’AMP-activated protein kinase (AMPK) along with stimulation of mitogen-activated protein kinase. Insulin resistance is a consequence of AMPK inhibition, an adaptive response designed to preserve cellular homeostasis.
Conclusion. Obesity, metabolic syndrome, chronic systemic inflammation, age-related syndromes and diseases (including arterial hypertension, atherosclerosis, neurodegenerative diseases, tumors, osteoarthritis, sarcopenia, etc.) can be considered as clinical manifestations of the body’s systemic adaptation to hyperinsulinemia in the form of insulin resistance. Available approach to reduce insulin resistance is correction of lifestyle factors to mitigate hyperinsulinemia and restore AMPK activity. The revealed causal relationships can provide background for personalized strategy of prevention and treatment for age-related diseases through reduction of insulin resistance and correction of energy homeostasis.
Relative energy deficiency in sport: modern approaches to diagnostics, treatment and prevention
In recent years, close attention has been paid to energy deficiency in professional athletes. More and more studies confirm the widespread prevalence of relative energy deficiency syndrome in sports and its relationship with various pathological conditions that lead to a decrease in the level of athletic performance. Nowadays the possibilities of early diagnosis and treatment of this syndrome are being carefully studied, and clinical protocols are being actively developed to facilitate the early detection of energy deficiency.
The aim of the study was to summarize the modern data on the influence of the syndrome of relative energy deficiency in sports on the health and performance of athletes, as well as to consider effective methods for the diagnosis, treatment and prevention of this syndrome.
Material and methods. The search was carried out using the Google Academy engine and electronic databases PubMed, MEDLINE, EMBASE, Scopus, Web of Science, eLIBRARY for the period from 2017 to 2021. For the search, we used keywords and their combinations: “relative energy deficit in sports”, “female athlete triad”, “menstrual dysfunction”, “osteoporosis”.
Results. Based on our analysis, we can conclude that the syndrome of relative energy deficit in sports has a multicomponent negative effect on the athlete’s organism and negatively affects his performance, well-being and sports results. Diagnosis of this condition is challenging due to the nonspecificity and variety of symptoms. Key diagnostic methods include physical examination, anamnesis gaining, dual energy X-ray absorptiometry, bioimpedance body composition analysis, and hormonal profile studies. Additional methods include: electrocardiography, study of the basal metabolic rate, hematological examination (hemoglobin, ferritin, etc.), determining the level of energy consumption using diaries of food and physical activity, determining blood vitamin level, etc. To facilitate the screening, diagnosis and follow-up of athletes, it is possible to use specially developed clinical protocols. Non-drug nutritional correction and optimal training plan are the main methods of treatment and prevention of energy deficiency. If this type of treatment is ineffective, hormone therapy should be considered. It is recommended to use transdermal estrogen therapy in combination with short-term progestin therapy. In some cases, when very low bone mineral density or delayed fracture consolidation is detected, it is possible to use recombinant parathyroid hormone.
Conclusion. Due to the relatively high prevalence of relative energy deficiency syndrome in athletes of both sexes and its long-term negative impact on athlete health and performance, further research is needed to improve the effectiveness of early diagnosis, prevention and treatment of pathological conditions associated with malnutrition.
Assessment of the influence of an enzymal preparation – a complex of glucoamylase and xylanase from Aspergillus awamori Xyl T-15 on the intestinal microbiom and immunological indicators of rats
The requirements for the safety of food products obtained by microbial synthesis are including as obligation for to conduct toxicological studies – the study of various biochemical and immunological markers of toxic effects. The necessity of these studies is explained by a possible change in the structure of food ingredients produced by a microbial cell and, consequently, a change in their biological properties, as well as the possible presence of living forms and/or DNA of producer strains or of their toxic metabolites in these ingredients. At the same time, it is well known that the nutrient composition of foods has a significant impact on the composition and properties of microorganisms that make up the gut microbiome, which, in turn, determines the immune status.
The purpose of the research was to justify the analyses of gut microbiocenosis composition for inclusion in the protocol of safety investigation of foods obtained by microbial synthesis [on the example of an enzyme preparation (EP) – a complex of glucoamylase and xylanase from a genetically modified strain of Aspergillus awamori Xyl T-15].
Material and methods. In experimental studies carried out for 80 days, Wistar rats (males and females) were used. The study of the effect of EP (a complex of glucoamylase and xylanase from a genetically modified Aspergillus awamori Xyl T-15 strain) in dozes 10, 100 and 1000 mg/kg body mass on the cecum microbiome and the immune status (content of cytokines and chemokines: IL-1a, IL-4, IL-6, IL-10, IL-17A, INF-γ, TNF-α, MCP-1, MIP-1a and Regulated on Activation Normal T-cell Expressed and Secreted – RANTES) was carried out.
Results. It has been shown that EP – a complex of glucoamylase and xylanase from A. awamori Xyl T-15 at doses of 100 mg/kg or more causes mild disturbances in the composition of gut microbiocenosis. At the same time, these disorders have a significant immunomodulatory and immunotoxic effect on the body, which manifests itself in a dose-dependent change in the profile of pro-inflammatory cytokines and chemokines in blood and spleen. The adverse effect of EP on the body is probably due to the formation of metabolites that are not formed during usual digestive processes in the gastrointestinal tract. The minimum effective dose (LOAEL) of EP was 100 mg/kg body weight In accordance with established requirements, the activity of the EP should not appear in ready-to-use food. Subject to this requirement, amount of EP entering the body cannot exceed the established LOAEL level. Therefore, a complex of glucoamylase and xylanase can be used in food industry, subject to the establishment of regulations «for technological purposes» for A. awamori Xyl T-15 strain.
Conclusion. The data obtained on the relationship between the state of the microbiome and the immune status upon the introduction of EP indicate the need to include indicators of the state of gut microbiocenosis in the test protocol of safety.
On integration of the iodine deficiency elimination and salt reduction programs
Excessive salt intake is a risk factor for noncommunicable diseases, but salt iodization is the most effective method of population-based prevention of iodine deficiency. Therefore, an assessment of dietary iodine intake from the use of iodized salt in the food industry and potential reductions in salt intake is needed.
Objective. To assess the feasibility of integrating iodine deficiency prevention and salt reduction programmes among the adult population in the Republic of Belarus.
Material and methods. Using the thiocyanate-nitrite method, the determination of iodine in various types of foods was carried out. Taking into account the actual dietary intake, estimated using the frequency method among 583 respondents over 18 years old, living in Minsk, from various socioeconomic groups, alimentary iodine intake was assessed at different levels of salt use in households. The level of iodine sufficiency was additionally estimated on the base of urinary excretion data obtained by the cerium-arsenite spectrophotometric method in 100 healthy adults over the age of 18 living in Minsk (65 women and 35 men).
Results. As part of the legal framework for the use of iodized salt in food production, there has been a steady increase in iodine levels in the target products (bakery and meat products to 42.0 and 133.3 µg/100 g respectively). The content of the discussed micronutrient in the diet of the adult population has raised at least 1.9-fold in recent decades, to 237.3 µg/day in the most realistic consumption model. The main source of iodine among this subpopulation is commercially produced foods with iodized salt, which forms 30–58% of the alimentary iodine exposure. Consumption of salt in Belarus averages 10.6 g per day, which poses a risk of developing noncommunicable diseases and necessitates programmes to reduce the level of salt in the diet. Modeling of scenarios with reduction of salt use in households in accordance with the recommendations of the World Health Organization (WHO) shows that the main contribution to dietary iodine exposure will be made by bread products (38%), about 1/3 will be formed by table salt, the value of non-target fortified products (milk and eggs) will increase (up to 21%). The contribution of table iodized salt to the dietary iodine exposure reaches 43% at actual consumption levels and will decrease to 18% if it is reduced to the WHO recommended values. The median of ioduria among those surveyed is 136.8 µg/l, indicating adequate iodine supply.
Conclusion. In implementing joint programs on prevention of iodine deficiency and cardiovascular diseases associated with excessive salt intake, it is necessary to consider national conditions – mandatory use of iodized salt in food industry, its level of fortification, content of this micronutrient in foodstuffs and structure of their consumption among certain population groups.
Prevalence of overweight and obesity in children
The growing prevalence of overweight and obesity is an urgent problem not only in adults but also in children in both developed and developing countries.
The purpose of this study was to analyze the prevalence of overweight and obesity and other forms of nutritional disorders in Russian children.
Material and methods. The nutritional status of 17 329 children aged 2–18 years was assessed on the basis of anthropometric data, obtained by the Federal State Statistics Service during the “Sample Survey of the Population’s Diet” in 2018. The prevalence of various forms of malnutrition was assessed by the Z-score categories: underweight, stunted growth (short stature), thinness, overweight, obesity.
Results. Population mean and median values of Z-scores in all sex-age groups do not exceed ±0.5 in relation to WHO standards, which indicates the applicability of the standards to assessing the nutritional status of Russian children population. High body weight (WAZ>2) occurs in 7.6% of children, underweight in 2.6%. The incidence of short stature in boys and girls is 7.0 and 6.8%, respectively. The prevalence of overweight and obesity in boys is 20.4 and 10.4%, respectively, while in girls, 15.4 and 7.6%. In general, in the population of children 2–18 years old, the prevalence of overweight is 18%, and obesity is 9.1%. The index of malnutrition, including the sum of the frequency of various combinations of low Z-scores (<-2), characterizing underweight, short stature, thinness, and their combinations was 8.0%. The multilevel logistic regression showed that overweight and obesity inversely depend on age; the risk of developing these conditions is lower in the city, but higher in male children compared to female children.
Conclusion. The population of children 2–18 years old in the Russian Federation is characterized by a low incidence of forms of malnutrition, such as underweight and thinness. However, the prevalence of overweight and obesity is higher than in European countries.
Dietary changes in males from adolescence to adulthood: results of a 28-year prospective study
Dietary pattern usually changes with age; however, certain dietary habits may remain constant.
The goal of this study was to analyze dynamic changes in the dietary pattern of males from adolescence to adulthood during a 28-year prospective follow-up.
Material and methods. Initially, a representative population sample of 1,005 boys aged 11 to 12 years (mean age 11.9±0.1 years) was examined. Four visits were performed at the ages of 15, 17, 22 and 43. Assessment of actual dietary pattern was carried out by the 24-hour dietary recall method.
Results. It was discovered that dietary pattern was changing with age as follows: proportions (∆%) of meats [M (95% confidence interval)] 2.4 (-0.5–5.3), fish and seafood 1.5 (0.4–2.7), eggs 0.8 (0.1–1.5), and vegetable oils 0.3 (0.1–0.5) were increasing with age, whereas the proportions of animal fats -1.0 [-1.4…-0.6], bread and bakery -2.8 [-5.5…-0.1], sweets and confectionery -2.6 [-4.8…-0.5] were decreasing. We also observed a trend of increased consumption of fruits and fruit juices [∆=4.9 (1.5–8.4)%]. The magnitudes of the tracking coefficients (correlation coefficients) between the initial (at the age of 15 years) values of the contributions of the main food groups to the total weight of the daily diet and their values at subsequent stages of prospective study showed that eating habits, as a certain dietary pattern, are relatively stable only in adolescence.
Conclusion. Over 28 years of prospective observation of males, from adolescence to adulthood, their eating patterns underwent significant changes, which must be taken into account when developing preventive measures aimed at correcting unhealthy dietary patterns in children and adolescents, and at transition to a balanced diet.
Keywords: dietary pattern; food groups; daily ration; dietary habits; adolescence; adulthood; tracking
Social jetlag: possibilities of micronutrient support
The concept of social jetlag refers to asynchronous communication of a person’s biological clock with tempo of modern living, which occurs mainly as a result of intensive work. At the core of social jetlag is sleep deprivation or chronic sleep restriction caused by social factors: pervasive use of electronic solutions and networks, intensive round the clock operation, chronic diseases.
The aim of the work was to determine vitamins, minerals, and other micronutrients, the availability of which is important for supporting the organism in case of circadian rhythm sleep disorders and sleep restrictions, the so-called social jetlag.
Material and methods. The analysis of 78 sources from PubMed and Google Scholar bibliographic bases was carried out with a detailed analysis of data from the published studies.
Results. Circadian rhythm sleep disorders and sleep restrictions affects cognitive functions, increasing risk of anxiety and depressive disorders, enhances processes of chronic inflammation, oxidative stress, cardiometabolic disorders. Scientific evidence has been collected that lack of such elements as magnesium, folates, omega-3 polyunsaturated fatty acids and probiotics in diet can worsening effects of social jetlag and increase the risk of chronic diseases. Preventive course intake of this micronutrients is reasonable in people predisposed to social jetlag.
Conclusion. In risk groups of people predisposed to social jetlag, along with diverse diet and adequate nutrition, sleep hygiene, it is necessary to provide targeted supplementation with magnesium, folates, omega-3 polyunsaturated fatty acids and probiotic products.
Amaranth grain proteins: prospects for use in specialized food products
Amaranth is a widespread genus of predominantly annual herbaceous plants belonging to the Amaranthaceae family, which is one of the most widely used pseudocereals along with quinoa and buckwheat in nutrition.
The aim of the research was to review and analyze the results of the studies on the characteristics of amaranth grain proteins, the effect of various food processing methods on their quality, and the prospects for using amaranth protein hydrolysates in therapeutic nutrition.
Material and methods. For the main search for the literature, the PubMed bibliographic database was used, which covers about 75% of the world’s medical publications. In addition, Scopus and Web of Science databases and non-commercial search engine Google Scholar were used. The depth of the search was 15 years.
Results. The paper presents a brief review of modern approaches for obtaining amaranth protein isolates and concentrates, including the use of a complex of physicochemical methods: grinding, sifting, extraction at high pH values, defatting, ultrafiltration, centrifugation, isoelectric precipitation, and drying of the protein product. A comparative characteristic of amino acid content of protein fractions of pseudocereals is presented. Basically, leucine, isoleucine, and valine are limiting amino acids for the grain protein of various varieties of amaranth. When substantiating and developing modern effective food technologies for processing amaranth grain, the studies dedicated to the evaluation of their impact on the biological value of amaranth protein deserve special attention. Methods of grain fermentation, sprouting, steaming, malting, boiling can be used to increase the bioavailability and digestibility of its ingredients. The results of in vitro and in vivo studies indicate the presence of hypotensive, hypolipidemic and antioxidant activity of the amaranth protein and its hydrolysates what determines the prospects for their use as part of foods for special dietary uses and therapeutic nutrition. An analysis of the scientific publications presented in the review indicates an increase in demand for high-quality gluten-free products and an increase in the range of mass-consumption foods, such as bakery, pasta, flour confectionery, with pseudo-cereals in their composition, including amaranth.
Conclusion. The high biological value and technological properties of amaranth protein concentrates/isolates determine the prospects for their use to create a wide range of specialized foods for various purposes.
Identification and chromate-mass-spectrometry quantification of toxic chemicals (N-nitrosamines, phthalates) in baby foods
Currently, assessing exposure to toxic chemicals detected in foodstuffs is a vital issue, especially regarding foods for babies and toddlers.
The research goal was to identify and quantify toxic chemicals (N-nitrosamines, phthalates) in baby foods.
Material and methods. Our research objects were 21 samples of canned meat and vegetable purees; 30 samples of juices. All samples were bought in retail outlets. We applied solid phase extraction to prepare the samples for the chromatographic analysis. Chemicals were identified in samples by a hybrid technique, gas chromatography and quadrupole mass spectrometry (GC-MS). The components were classified by comparing the mass spectra we obtained with spectra of specific chemicals and data from the following libraries: NIST 08.L, WILEY275.L and PMW_TOX2.L, AMDIS, USEPA (US Environmental Protection Agency) database with identification numbers of environmental pollutants; libraries containing mass spectra of narcotics, drugs, toxic pollutants and pesticides. Quantitative determination of phthalates in juice products by HPLC/MS was performed.
Results. We identified three toxic chemicals in the analyzed canned meat and vegetable purees for babies. They belonged to the 1–3 hazard category and to different classes of organic compounds. Specifically, we identified nitrogen-containing chemicals (N-nitrosamines within a range of concentrations being 0.00077–0.0015 mg/kg with a 73% probability that a mass spectrum would match one taken from a library) in 52.9% of samples. These chemicals are not allowed in canned meat purees for babies by the Technical Regulations TR CU 021/2011 (<0.001 mg/kg). Next, we identified dibutyl phthalate and diethyl phthalate in 30.0% of samples; contents of these organic compounds in canned meat purees for babies are not stipulated by the TR CU 021/2011. We also identified an aromatic compound, namely furfural in 21.7% of samples, and a food additive, 2-butenoic acid (E570) in 5.3% of samples; their contents are regulated by the Technical Regulations TR CU 029/2012. Three toxic chemicals were identified in the analyzed juice samples. First, N-nitrosodiethylamine and N-nitrosodimethylamine were identified in 56.7% of samples (with a 73% probability that a mass spectrum would match one taken from a library, over a concentration range of 0.00045– 0.00077 mg/kg). Second, we identified phthalates (dibutyl phthalate, diethyl phthalate, and diisobutyl phthalate) in 30% of samples (in the concentration range from 0.4 to 59.26 mg/l). The contents of these compounds in juices for babies are not regulated by the TR CU 021/2011. We also detected furfural in 56.7% of samples (with a value of the coefficient of coincidence with library data of 90%), the use of which is regulated in TR CU 029/2012.
Conclusion. We have developed and experimentally substantiated an algorithm of an analytical study with its focus on preparing food samples for further identification of chemicals in them. The algorithm involves using a complex technique that combines distillation, solid phase extraction, gas chromatography and mass spectrometry. This technique provides an opportunity to identify a component structure of complex chemical mixtures in food samples with high probability and reliability. It also provides solid evidence that organic compounds occur in food samples based on comparing analytical mass spectra with those taken from mass spectral libraries.
Russian market of fermented kombucha beverages
Fermented beverages based on kombucha contain a wide range of minor biologically active substances (flavonoids, caffeic acid derivatives, B vitamins, and others). The inclusion of these beverages in the diet helps to increase its nutritional value due to the content of biologically active substances, including essential ones. To develop beverages (kombucha) with a certain content of biologically active substances, it is necessary to study the composition of these products sold on the Russian market.
The aim of the work was to analyze the Russian market of fermented beverages based on kombucha.
Material and methods. More than 100 different marketed products were selected, positioned as non-alcoholic fermented beverages based on kombucha.
Results. It was revealed that black tea (~28%), green tea (~24%) and Blooming Sally (~13%) are most often used as the basis for kombucha. In other cases, various types of tea, coffee, as well as special varieties of tea are used. Sugar (~55%), stevia extract (~24%), as well as honey, fructose, glucose-fructose syrup are used as sweeteners. The formation of the flavor profile of kombucha is achieved by using additional ingredients. A variety of fruits (lemon, orange, mango, apple, etc.), vegetables (cucumber, beetroot, etc.), berries (cranberries, lingonberries, chokeberry, raspberries, etc.) are used in the form of juices or purees; herbs and spices (mint, nutmeg, star anise, cloves, lavender, vanilla, etc.), as well as functional ingredients (vitamins, prebiotics, probiotics, chlorophyll) are applied as such additives.
Conclusion. The analysis of the range of fermented drinks (kombucha) marketed in trading network was carried out. A list of main and auxiliary ingredients has been formed to assess the possibility of using these drinks to modify eating patterns.