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Reviews

Probiotics as functional foods: production and approaches to evaluating of the effectiveness

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This review concerns the issues of food fortifications and the creation of functional foods (FF) and food supplements based on probiotics and covers an issue of approaches to the regulation of probiotic food products in various countries.

The status of functional foods, optimizing GIT functions, as a separate category of FF is emphasized. Considering the strain-specificity effect of probiotics, the minimum criteria used for probiotics in food products are: 1) the need to identify a probiotics at genus, species, and strain levels, using the high-resolution techniques, 2) the viability and the presence of a sufficient amount of the probiotic in product at the end of shelf life, 3) the proof of functional characteristics inherent to probiotic strains, in the controlled experiments. The recommended by FAO/WHO three-stage evaluation procedure of functional efficiency of FF includes: Phase I – safety assessment in in vitro and in vivo experiments, Phase II – Evaluation in the Double-Blind, Randomized, Placebo-Controlled trial (DBRPC) and Phase III – Post-approval monitoring. It is noted that along with the ability to obtain statistically significant results of the evaluation, there are practical difficulties of conducting DBRPC (duration, costs, difficulties in selection of target biomarkers and populations). The promising approach for assessing the functional efficacy of FF is the concept of nutrigenomics.

It examines the link between the human diet and the characteristics of his genome to determine the influence of food on the expression of genes and, ultimately, to human health. Nutrigenomic approaches are promising to assess the impact of probiotics in healthy people. The focusing on the nutrigenomic response of intestinal microbial community and its individual populations (in this regard the lactobacilli can be very informative) was proposed.

Physiology and biochemistry nutrition

L-arginine metabolism enzyme activities in rat liver subcellular fractions under condition of protein deprivation

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The features of arginase and NO-synthase pathways of arginine’s metabolism have been studied in rat liver subcellular fractions under condition of protein deprivation. During the experimental period (28 days) albino male rats were kept on semi synthetic casein diet AIN-93. The protein deprivation conditions were designed as total absence of protein in the diet and consumption of the diet partially deprived with 1/2 of the casein amount compared to in the regular diet. Daily diet consumption was regulated according to the pair feeding approach. It has been shown that the changes of enzyme activities, involved in L-arginine metabolism, were characterized by 1,4–1,7 fold decrease in arginase activity, accompanied with unchanged NO-synthase activity in cytosol.

In mitochondrial fraction the unchanged arginase activity was accompanied by 3–5 fold increase of NO-synthase activity. At the terminal stages of the experiment the monodirectional dynamics in the studied activities have been observed in the mitochondrial and cytosol fractions in both experimental groups.

In the studied subcellular fractions arginase activity decreased (2,4–2,7 fold with no protein in the diet and 1,5 fold with partly supplied protein) and was accompanied by NO-synthase activity increase by 3,8 fold in cytosole fraction, by 7,2 fold in mitochondrial fraction in the group with no protein in the diet and by 2,2 and 3,5 fold in the group partialy supplied with protein respectively. The observed tendency is presumably caused by the switch of L-arginine metabolism from arginase into oxidizing NO-synthase parthway.

Influence of enzymatic hydrolyzate of mussels meat on growth and some indicators of general adaptation syndrome in rats

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The impact of the 15-day consumption of enzymatic hydrolyzate of the mussels meat as a part of semi-synthetic diet on some stress biomarkers and apoptosis activity in various organs of growing male Wistar rats have been studied.

Enzymatic hydrolyzate of the mussels meat (EMM) was obtained in pilot conditions using the enzyme preparation ≪Protozim≫. The animals of control group 1 (n=8 with initial body weight of 179,4Ѓ}5,9 g) and experimental group 2 (n=8, 176,3Ѓ}4,5 g) received a semi synthetic diet; the animals of the experimental group 3 (n=8, 177,6Ѓ}4,0 g) received the same semi synthetic diet in which 50% of the casein was replaced by the peptides of EMM. On the penult day of the experiment animals of groups 2 and 3 were subjected to stress exposure by electric current on their paws (current 0,4 mA for 8 seconds) and were placed in metabolic cages for the collection of daily urine. At the 15th day of the study, all control and test animals were killed by decapitation under ether anesthesia and necropsied. The content of prostaglandin E2 and β-endorphin in blood plasma was determined by ELISA test. The concentration of urine corticosterone was measured by HPLC. DNA damage and percentage of apoptotic cells (apoptotic index) were calculated in thymus by single-cell gel electrophoresis assay (Comet assay). The relative body weight increase of animals treated with EMM was significantly (p<0,05) higher (68,2Ѓ}3,0%) than those in animals of groups 1 and 2 (57,2Ѓ}4,0 and 59,7Ѓ}2,8%, respectively). The apoptotic index in thymus cells of tested groups of animals (2 and 3) was significantly (p<0,05) higher (1,13Ѓ}0,09 and 1,09Ѓ}0,01%) compared to intact animals of control group (1,04Ѓ}0,01%). Determination of β-endorphin and prostaglandin E2 levels did not shown any significant differences between the groups. Significantly (p<0,05) lower concentrations of corticosterone was found in the daily urine of stressed animals from group 3 (452Ѓ}78 ng/ml), treated with EMM, compared to stressed animals of group 2 that received a casein diet (834Ѓ}167 ng/ml). It has been shown that consumption of EMM with a high content of short and medium peptides has an impact on effectiveness of body weight gain of growing laboratory animals, and restrict the increase of corticosterone level in rats blood, which is typical for general adaptation syndrome.

Correction of the combined vitamin deficit in growing rats fed fiber enriched diets with different doses of vitamins

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The effect of 5% dietary wheat bran (WB) on the correction of combined vitamin deficiency by two doses of vitamins (physiological and enhanced) has been analyzed using a rat model (8 groups, n=8/group). Vitamin deficiency in male weanling Wistar rats (58,1Ѓ}0,5 g) was induced by 5-fold reduction of vitamin mixture amount in the feed and complete vitamin E, B1 and B2 exclusion from the mixture for 30 days, then deficit was corrected within 5 days. Rats from control group were fed a complete semisynthetic diet containing microcrystalline cellulose 2%. Vitamin deficient diet for 35 days resulted in reduced (p<0,05) levels of vitamin A in the liver by 25 fold, vitamin E and B1 – 2,0–2,3 fold, vitamin B2 – by 40%, 25(OH)D blood plasma concentration – by 21% compared with the control. Feed consumption of the animals treated with vitamin deficient diet and WB was higher by 43% than in rats with vitamin deficit. Their rate of weight occupied the intermediate position between the rates of weight in deficit and in control animals, and they could not serve a full control to evaluate the WB impact on vitamin sufficiency. After filling the vitamin diet content to an adequate level vitamin E liver content was fully restored. To restore vitamins B1 and B2 liver level higher doses of vitamins (120–160% of adequate content) were required, and to restore the reduced levels of vitamin A in rat liver even 2-fold increased dose of vitamin A was insufficient. The diet enrichment with WB had no effect on vitamin B1 and B2 liver content, regardless of the amount of vitamins in the diet.

Adding fiber to the diet of animals adequately provided with vitamins resulted in significantly 1,3-fold increase of 25(OH)D blood plasma concentration and a slight but significant decrease of α-tocopherol liver level by 16% as compared to rats not receiving WB. The enrichment of rat diet with dietary fibers worsened restoration of the reduced vitamin E status not only by filling vitamin content in the diet to an adequate level, but also by using 2-fold enhanced dose of vitamin.

Within 5 days deficiency of vitamins A, B1, B2 was not eliminated with increasing vitamin diet content to an adequate level. Higher doses of vitamins are needed for the complete correction of vitamin status. The addition of vitamins to an adequate level was sufficient to normalize the elevated liver levels of MDA in rats with combined vitamin deficiency that may be associated with vitamin E status improvement. The diet enrichment with fiber did not affect on the intensity of lipid peroxidation in rat liver regardless of their provision with vitamins.

Age-dependent characteristics of nutritional status and resting metabolism in overweight and obese children

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The age-dependent nutritional status and resting metabolism in overweight and obese children have been examined. The study included 625 children of 2,5–17 years old. Patients were divided into three groups: 1st – 2,5–7 years old (n=49), 2nd – 8–12 years old (n=204), 3rd – 13–17 years old (n=372). The diagnosis of overweight and obesity was based on CDC criteria: children with 85–94 BMI percentile according to age and gender had overweight, BMI 95 percentile – obesity. Anthropometry, bioelectric impedance analysis and indirect respiratory calorimetry were performed; lipid and carbohydrate parameters were measured. The fat mass percentages in children of studed groups were 41,3Ѓ}1,9, 39,8Ѓ}0,7 and 42,3Ѓ}0,4%, the mean percent of fat mass excess – 163,6Ѓ}26,2, 113,7Ѓ}8,3 and 134,9Ѓ}8,2% respectively, p>0,05.

Prevalence of dyslipidemia in children increased with age: lipid metabolism disorders were revealed in 28,6, 49,0

и 53,2% children of the 1st, 2nd and 3rd groups respectively. The mean HDL level in the 1st and 2nd groups was significantly higher, and triglycerides – lower than in the 3rd group. The correlation of HDL level and breastfeeding duration (r1=0,94, p<0,05) was found in the 1st group of children. Increased insulin level was revealed in 38,8% children in the 1st group (mean 12,8Ѓ}1,4 μIU/ml), 62,2% children in the 2nd group (21,1Ѓ}0,7 μIU/ml) and 64,8% children in the 3rd group (25,1Ѓ}0,9 μIU/ml); increased HOMA – in 36,7% (4,32Ѓ}0,6), 62,2% (4,65Ѓ}0,17) and 59,1% (5,56Ѓ}0,21) respectively. The negative correlation of insulin and HOMA level with breastfeeding duration (r1=0,38 and 0,37, respectively, p<0,05) was found in the 1st group of children. Prevalence of hyperuricemia increased from 13% in the 1st group to 21,1% in the 2nd and 44,1% in the 3rd group. Prevalence and degree of resting metabolism changes increased with age and had tendency to the shift of proportion of energy-intensive substrates (fats and carbohydrates) to deceleration of carbohydrate oxidation (in 32, 50, 55,1% of children) and compensatory fat oxidation acceleration (8, 28,4 and 34,7% respectively). Mean fat oxidation rate levels significantly differed between groups and increased with age (48,38Ѓ}7,14, 54,29Ѓ}3,06 and 78,43Ѓ}2,89 g/day in children of the 1st, 2nd and 3rd groups respectively, p<0,001).

The mean level of carbohydrate oxidation rate in the 3rd group of children was lower than normal value (p<0,01). Resting energy expenditure was lower in the 2nd and 3rd groups of children.

The system of quality control and food safety

Regulation of food supplements in the European Union and its member States. Part 2

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The article discusses various aspects of the regional (the European Union) and national (European countries) regulation related to food supplements. The use of botanicals and minor bioactive substances in food supplements, and their labelling are studied. The EU principle of mutual recognition is described in the context of current challenges that exist in the regulatory harmonisation between the EU member states. The concept of novel foods and novel ingredients is also presented, and the procedure of their pre-market approval is described in detail.

Basic principles of using claims for food supplements are also outlined.

Hygiene of nutrition

Toxicological assessment of nanostructured silica. II. Enzymatic, biochemical indices, state of antioxidative defence

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Nanostructured silica (SiO2) ≪Aerosil≫ with the size of the primary nanoparticles (NPs) of 5–30 nm, in the form of ultrasound treated water suspension was administered to rats of 80Ѓ}4 g initial body weight for the first 30 days by intragastric gavage and then for 62 days with diets consumed in doses of 0,1; 1,0; 10 and 100 mg/kg body weight per day. The control group received vehicle of nanomaterial (NM) – deionized water. There were measured in liver of animals the content of total cytochromes P450 and b5 in the microsomal fraction of liver, activity (Vmax) of microsomal monooxygenases with the mixed function of isoforms CYP1A1, 1A2 and 2B1 on their specific substrates, the activity of conjugating liver enzymes glutathione-S-transferase and UDP-glucuronosyltransferase in microsomal fraction and cytosol, the total and non sedimentable activity of lysosomal hydrolases (β-glucuronidase, β-galactozydase, arylsulphatase А, В). The content of PUFA’s diene conjugates and TBA-reactive substances in the blood plasma and the activity of antioxidative enzymes (glutathionperoxidase, superoxidedismutase, glutathionreductase, katalase) in erytrocytes were estimated. A set of standard biochemical parameters of blood serum was also examined (total protein, albumin, glucose, creatinine, urea, uric acid, activities of hepatic transaminases). The studies revealed changes of a number of molecular markers that could be interpreted as unfavorable. These include isoforms of CYP2B1 activity decrease at a dose HM 1–10 mg/kg of body weight, decrease in the serum content of total protein, albumin and glucose levels in a dose range of 0,1–10 mg/kg. These changes were absent at the maximum dose of NM, which did not allow to clearly establish the dose-response. The remaining studied figures resided in the normal range or experienced changes that could not be interpreted as toxic.

The specificity of schoolchildren’s eating habits in Moscow and Murmansk

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Objective of the study is to evaluate the specificity of schoolchildren’s eating behavior in the cities оf Moscow and Murmansk. Dietary habits of 785 children 10–17 years old residing in two cities – Moscow (222 boys and 221 girls, 14,1Ѓ}1,9 years old) and Murmansk (183 and 159 correspondingly, 14,1Ѓ}1,8 years old) – were analyzed. The questionnaire included data on the meals ratio per day, frequency of vegetables and fruit intake, fast-food intake, hot meals, soft drinks, meat, fish and milk intake, usage of school cafeteria, regularity of breakfasts. Parents responded to questions concerning the material support of family and education. It was found that more than half of schoolchildren (64,4%) had meals irregularly (3 times per day or less), only 50,9% received hot meals several times a day. Every third child (31,6%) has insufficient intake of vegetables and fruit, 11,8% – insufficient intake of meat dishes. Only 51,4% of schoolchildren consumed dairy products daily (one or several times a day). At the same time 19,5% of children used fast-food products several times a week or more often, 42,2% – carbonated drinks, and 22,7% – smoked food. Only 45,7% of schoolchildren regularly ate at school cafeteria; 21,9% did it irregularly and 32,5% – did not attend school canteen at all.

There were no significant differences between Moscow and Murmansk children as well as gender differences in the usage of school cafeteria. At the same time only 23,4% of children [26,3% in Moscow and 19,3% in Murmansk (significantly less, p=0,032)] liked cafeteria food, 38,7% did not like and 37,9% had no certain answer. Less obese children (54,0%) have breakfast everyday than children with normal weight (75,4%, p=0,019). Children of mothers with high and incomplete high education (89,4%) have more regular meat intake (3–4 times per week or more often) than the children of mothers with secondary, incomplete secondary and secondary special education (81,9%, p=0,034). Schoolchildren feeding is often irregular, irrational and poorly balanced. Some of examined schoolchildren already had excessive body mass (20,7%), that may lead to metabolic and cardiovascular disturbances in young adult and mature age.

Comparative evaluation of antioxidant activity and content of prooxidant factors in different classes of foods

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By using the biophysical methods (chemiluminescence, amperometry) in laboratory in vitro experiments it was demonstrated that the study of antioxidant and pro-oxidant activities of different food groups allows to perform a preliminary assessment of their pro-oxidant-antioxidant capacity. It have been shown that some food prevails ability to exert pro-oxidant effects (in vitro) due to the short-term induction of free radical oxidation. Thus, among the fresh juices the increase of the maximum of flash chemiluminescence has been detected in avocado (1080,89%) and pear juices (136,33%), whereas the lowest ability to enhance the intensity of free radical processes has been marked for pomegranate (1,63%), orange (9,68%) and apples juices (12,84%). Among milk products it has been marked for sour milk (9,06%) and yogurt (15,11–16,02%), that allows the use of the past to correct pro-oxidant-antioxidant balance diet for people with potential danger gain peroxide processes, such as special physiological states, sport endurance, mental and emotional overload. The ability to increase the intensity of free radical oxidation have been also identified for snacks, especially buns, biscuits, bread sticks, showing the risk of formation of oxidative stress in the body during their prolonged use, particularly under the above described conditions. In some cases, foods (processed cheese and cheese curds) showed dominance factors sustained oxidative effect (in 2,1–20,7%), that indicates the possibility of an imbalance in the prooxidantantioxidant system after its prolonged use in the diet, even in small quantities, especially in individuals with a reduced level of antioxidant potential of the nonspecific defense system. Investigation of antioxidant activity of foods revealed significant predominance of reducing equivalents in all freshly squeezed and some packaged fruit juices, as well as dairy products, indicating their possibility to increase the capacity of reducing components of nonspecific protection system. The presence in a number of products used for snacking (chips, puffed rice) of sufficiently high levels of antioxidant activity demonstrates the content of substances that act as proton donator having significant reducing ability. It is sufficient for high energy value of such products, indicating on the possibility of involvement of their recovery factors in plastic processes with subsequent enhancement, such as lipogenesis, that may be a prerequisite for the development of obesity, atherosclerosis and other pathological processes. Using an integrated approach will enable a timely and appropriate to correct the ratio of pro- and antioxidant indicators of diet in order to improve the adaptive capacity of the organism in a particular physiological or pathological conditions involving oxidative metabolism disorders.

Intensity of lipid peroxidation and protein oxidative modification of goat and cow milk

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Indices of free-radical peroxidation have been estimated: intensity of lipid peroxidation and protein oxidative modification of goat and cow milk of specific breeds of forest-steppe zone of Omsk region. The obtained results indicate that processes of lipid peroxidation and protein oxidative destruction in goat and cow milk of different breeds occur with different gradation. The content of carbonile derivatives in goat milk of Saan breed 1,4 (0,95; 1,5) u/ml was lower than in cow’s milk of black-and-white breed 4,6 (1,1; 6,0) u/ml (p=0,005) what could be caused by large content of protein thiol groups of this kind of milk and lower quantity of amino acid residues that are available for carbonylation. This kind of milk is characterized by higher SH-group content than cow milk for 31% and Switzerland goat milk for 20% (р=0,005). The content of cetodiens and attached triens in isopropanol phase of the lipid extract of goat milk of Swiss breed is lower by 30% than in cow milk. In isopropanol phase of the milk lipid extracts containing phospholipids the level of Schiff grounding did not differ. The results obtained prove that goat milk contain less protein subjected to oxidative modification

Book review

Review of N.R. Efimochkinoy’s book «Microbiology of foodstuff and modern methods of detection of pathogens»

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In the present review of the book N.R. Efimochkina ≪Microbiology of food and modern methods of pathogen detection≫ attention is drawn on the key issues of food safety for consumers, monitoring research on microbiological indicators. Attention is paid to efficient control requirements of the legislation of food at all stages: from raw materials to the consumer’s table and the value of the observations on food contamination by microorganisms has been demonstrated. Considerable attention is paid to the mechanisms of genetic regulation of pathogenicity factors of bacteria, avoidance strategies from adverse environmental factors and the immune system to maintain the viability of the microorganism bacterial pathogens. Illustrative scheme of microbiological testing of food products deserves attention. The role of molecular biology to determine the etiological role of the pathogen has been emphasized. Data on new genera and species of pathogens listed by the author, are important for the practical activities of experts. Modern views on the ability of bacterial populations to the formation of biofilms, which can affect the effectiveness of sanitary regime of processing and eliminationof contaminants in terms of food manufacturing are detailed. When predicting the risk and safety of foods the role of anthropogenic and technogenic impacts to eliminate microbial or environmental effects of contaminants is shown. The section on microorganisms-indicators of pathogens is detailed and the stress responses of microorganisms to chemical, physical and biological influence as well as non-cultivated forms of bacteria, mathematical model of microbiological processes are shown. From the standpoint of modern judgments the position about emergent pathogens is described, with particular emphasis on Enterohaemorrhagic Escherichia coli. Modern research methods, including immunoassays, gel diffusion precipitation, unit and latex agglutination reactions, molecular detection of foodborne pathogens are presented.

The materials of this work can be used for the practical activity of the specialists of the laboratories equipped with modern facilities. We propose to expand the list of microorganisms of food product spoilage in the next edition. Materials of the fundamental work are of great importance for improving the knowledge of experts in the prevention of food poisonings and intestinal infections with alimentary factor of transmission and modern methods of research.

Information

Динамика селенового статуса и возможности его диетической коррекции у больных с острым Q-инфарктом миокарда*

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Обеспеченность селеном больных острым инфарктом миокарда с зубцом Q в Рязанском регионе

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Journals of «GEOTAR-Media»