Iurie Subotin - Academia.edu (original) (raw)
Papers by Iurie Subotin
Zenodo (CERN European Organization for Nuclear Research), Dec 15, 2020
The content of nitrates in foods of plant origin permanently comes into notice of consumers, soci... more The content of nitrates in foods of plant origin permanently comes into notice of consumers, society. Nitrates in large quantities are harmful to the human body, especially children. The legislation of the Republic of Moldova, which regulates the maximum acceptable limit (MAL) of nitrates, namely Government Decision No 115 on The control of nitrates in foods of plant origin, was brought into line with European legislation just in September 2020. In the present study, some aspects related to these normative changes were analyzed. It was determined that the vast majority of spinach samples from local agricultural market exceed 1.1-1.6 times the MAL of nitrates with reference to national legislation and 1.9-2.7 times concerning the legislation of the Russian Federation. Rucola practically falls within the limits established in the national legislation, the MAL being 6000 mg nitrate•kg-1 , but it exceeds by far (in 2.1 times) the MAL established in the Russian Federation. Fresh salad falls within the limits set by national and international laws.
Journal of Social Sciences, May 1, 2021
The article analyzes the possible methods for performing laboratory work in chemistry during a si... more The article analyzes the possible methods for performing laboratory work in chemistry during a situation of lockdown or pandemic. Laboratory practice is one of the main ways to learn the basics of science. The results of the experiments performed by the students stimulate their thinking, lead them to discussions and lead them to draw conclusions. All this leads to the optimization of the learning process. The use of very simple tools often helps in learning, facilitating the assimilation of the material. If the transfer of knowledge is not done correctly initially, then the subsequent understanding of the material will be more difficult to achieve. In the absence of a strong connection with previously studied topics it will be more difficult for students to think. Students begin to believe that science is difficult to understand, interest is often lost, and knowledge gained during the theoretical course may lose its value. People are naturally curious and always on the lookout, and the lab is a good place to satisfy that curiosity. In the laboratory, students have the opportunity to test their theoretical knowledge, which structures thinking and increases interest in science.
Studia Universitatis Moldaviae (Seria Ştiinţe Reale şi ale Naturii), Apr 1, 2008
GEOREVIEW: Scientific Annals of Stefan cel Mare University of Suceava. Geography Series, Apr 1, 2009
The Republic of Moldova has an enormous potential of exploiting the ecological agricultural and g... more The Republic of Moldova has an enormous potential of exploiting the ecological agricultural and genetic modified food products. Consumers, especially of EU market, have demanded both the conformity of products in regard to harmless effects and additional requirements for the quality. In this view, in the RM the Law on ecological agri-food products, 6 Governmental Decisions, 5 Presidential Decrees, 1 Ministerial Order and several standards were passed. The basic principles of ecological agrifood production have been proposed for adoption. Consumers, especially those on European Union markets, don't ask only the guarantees of confirmation of products and of harmlessness in consumption, but solicit additional confirmations concerning their quality, including ensurance that the products which they consume are pure ecological and genetic unmodified. For that reason, The Parliament of the Republic of Moldova adopted the law "Concerning ecological agrifood products" which anticipates settlement of social reports that are under to obtain ecological agrifood products without using the unending chemical substances, inclusively commercialization of ecological food products of vegetal and animal origin. Some general principles of ecological agrifood products were proposed.
Molecules
Sunflower oil (Helianthus annuus) contains a rich concentration of polyunsaturated fatty acids, w... more Sunflower oil (Helianthus annuus) contains a rich concentration of polyunsaturated fatty acids, which are susceptible to rapid oxidative processes. The aim of this study was to evaluate the stabilizing effect of lipophilic extracts from two types of berries, sea buckthorn and rose hips, on sunflower oil. This research included the analysis of sunflower oil oxidation products and mechanisms, including the determination of chemical changes occurring in the lipid oxidation process via LC-MS/MS using electrospray ionization in negative and positive mode. Pentanal, hexanal, heptanal, octanal, and nonanal were identified as key compounds formed during oxidation. The individual profiles of the carotenoids from sea buckthorn berries were determined using RP-HPLC. The influence of the carotenoid extraction parameters ascertained from the berries on the oxidative stability of sunflower oil was analyzed. The dynamics of the accumulation of the primary and secondary products of lipid oxidation ...
În articol sunt prezentate modele de situații didactice la disciplina școlară Chimia, prevăzute d... more În articol sunt prezentate modele de situații didactice la disciplina școlară Chimia, prevăzute de Regulamentul de atestare a cadrelor didactice din învățământul general, profesional tehnic și din cadrul structurilor de asistență psihopedagogică, aprobat prin ordinul Ministrului Educației, Culturii și Cercetării nr.1091din 07.10.2020. Sunt indicate și rezolvări ale acestor situații în conformitate cu algoritmul de prezentare din Regulament.
Universitatea Tehnică a Moldovei, 2020
The content of nitrates in foods of plant origin permanently comes into notice of consumers, soci... more The content of nitrates in foods of plant origin permanently comes into notice of consumers, society. Nitrates in large quantities are harmful to the human body, especially children. The legislation of the Republic of Moldova, which regulates the maximum acceptable limit (MAL) of nitrates, namely Government Decision No 115 on The control of nitrates in foods of plant origin, was brought into line with European legislation just in September 2020. In the present study, some aspects related to these normative changes were analyzed. It was determined that the vast majority of spinach samples from local agricultural market exceed 1.1-1.6 times the MAL of nitrates with reference to national legislation and 1.9-2.7 times concerning the legislation of the Russian Federation. Rucola practically falls within the limits established in the national legislation, the MAL being 6000 mg nitrate·kg-1 , but it exceeds by far (in 2.1 times) the MAL established in the Russian Federation. Fresh salad fa...
Food and Nutrition Sciences, 2021
The present study aimed to investigate the effectiveness of the use of some antioxidants-α-tocoph... more The present study aimed to investigate the effectiveness of the use of some antioxidants-α-tocopherol, n-octyl gallate, L-ascorbic acid 6-palmitate and matcha extract (green tea) as inhibitors of grape seeds, walnuts and corn germ oils oxidation. The oxidation was studied in a forced regime during 700 h, by the addition of hydrogen peroxide and Cu 2+ ions. The optimal conditions of the accelerated oxidation process in the analysed systems were established. The progress of lipid oxidation was evaluated by measuring the peroxide value (PV) and conjugated dienes and trienes (CD, CT). A series of secondary products of the lipid oxidation were identified: hexanal, octanal and hydroxy-nonadienal. The intensity of the formation of these compounds during oxidation was monitored. The results of this study showed that the oil samples with the addition of antioxidants showed considerably lower oxidation values compared to the control sample. More effective was the action of L-ascorbic acid 6-palmitate and n-octyl gallate, the optimum concentration was 0.1%. An inhibitory effect of the oxidation process was noted for αtocopherol and matcha extract, the optimal addition concentration was 1%.
Universitatea Tehnică a Moldovei, 2016
This article investigates the processes that take place during the forced thermooxidation of sunf... more This article investigates the processes that take place during the forced thermooxidation of sunflower oil. The results obtained in the study showed a major impact of thermo-oxidation. (90 ± 2 °C. supplied air with a speed of 8 ÷ 10 L·h-1 for 50 hours), on the physico-chemical indicators of the studied oil. The acidity index of fresh sunflower oil increased 13.7 times, with a value of 2.46 mg KOH·g-1 of fat for the thermo-oxidized oil compared to the initial value of 0.180 mg KOH·g-1 of fat. The thermo-oxidation of sunflower oil caused a significant decrease of the saponification index, which indicates a significant degree of polymerization and leads to viscosity increase of the studied sunflower oil. In order to highlight the impact of heat treatments, the analysis was performed by IR spectroscopy and the possible mechanisms of unsaturated fatty acids forced oxidation under the influence of thermal factor were analyzed. It was established that the applied treatment favoured both th...
Chemistry is an experimental science that is based on theoretical process and finds its applicati... more Chemistry is an experimental science that is based on theoretical process and finds its application in practical attempts in laboratory; it is based on experiment, as well as it is a method for scientific investigation, learning and evaluation. Having an experimental<br> character, chemistry can not be taught, learnt and evaluated without practical experiments. The experiment is a didactic method through which trained people have the purpose to carry out a chemical or physical process or phenomenon, or to modify their standard<br> conditions by introducing some new variables with the purpose to study them.
This paper is a didactic project to teach the topic "<em>Chemical bond and structure o... more This paper is a didactic project to teach the topic "<em>Chemical bond and structure of substance – didactic aspects</em>", that aims to help students understand the most important notions, laws and theories. In the process of mastering the material of the topic, skills should be improved for students to make inter-subject communications with physics and mathematics based on the application of knowledge about electrons, ions, and nucleus of an atom. Students should more often be given the opportunity to analyze the composition of substances and make conclusions about the nature of chemical bonds, compare the structure of atoms, simple and complex substances, establish a relationship with properties, and predict the type of crystal lattice based on the properties of substances, so they will be able to develop logical thinking skills. When studying the topic, ideas about the relationship of opposites, about the transition of quantitative changes to qualitative on...
The article analyzes the possible methods for performing laboratory work in chemistry during a si... more The article analyzes the possible methods for performing laboratory work in chemistry during a situation of lockdown or pandemic. Laboratory practice is one of the main ways to learn the basics of science. The results of the experiments performed by the students stimulate their thinking, lead them to discussions and lead them to draw conclusions. All this leads to the optimization of the learning process. The use of very simple tools often helps in learning, facilitating the assimilation of the material. If the transfer of knowledge is not done correctly initially, then the subsequent understanding of the material will be more difficult to achieve. In the absence of a strong connection with previously studied topics it will be more difficult for students to think. Students begin to believe that science is difficult to understand, interest is often lost, and knowledge gained during the theoretical course may lose its value. People are naturally curious and always on the lookout, and ...
The Republic of Moldova has an enormous potential of exploiting the ecological agricultural and g... more The Republic of Moldova has an enormous potential of exploiting the ecological agricultural and genetic modified food products. Consumers, especially of EU market, have demanded both the conformity of products in regard to harmless effects and additional requirements for the quality. In this view, in the RM the Law on ecological agri-food products, 6 Governmental Decisions, 5 Presidential Decrees, 1 Ministerial Order and several standards were passed. The basic principles of ecological agrifood production have been proposed for adoption. Consumers, especially those on European Union markets, don’t ask only the guarantees of confirmation of products and of harmlessness in consumption, but solicit additional confirmations concerning their quality, including ensurance that the products which they consume are pure ecological and genetic unmodified. For that reason, The Parliament of the Republic of Moldova adopted the law “Concerning ecological agrifood products” which anticipates settl...
Zenodo (CERN European Organization for Nuclear Research), Dec 15, 2020
The content of nitrates in foods of plant origin permanently comes into notice of consumers, soci... more The content of nitrates in foods of plant origin permanently comes into notice of consumers, society. Nitrates in large quantities are harmful to the human body, especially children. The legislation of the Republic of Moldova, which regulates the maximum acceptable limit (MAL) of nitrates, namely Government Decision No 115 on The control of nitrates in foods of plant origin, was brought into line with European legislation just in September 2020. In the present study, some aspects related to these normative changes were analyzed. It was determined that the vast majority of spinach samples from local agricultural market exceed 1.1-1.6 times the MAL of nitrates with reference to national legislation and 1.9-2.7 times concerning the legislation of the Russian Federation. Rucola practically falls within the limits established in the national legislation, the MAL being 6000 mg nitrate•kg-1 , but it exceeds by far (in 2.1 times) the MAL established in the Russian Federation. Fresh salad falls within the limits set by national and international laws.
Journal of Social Sciences, May 1, 2021
The article analyzes the possible methods for performing laboratory work in chemistry during a si... more The article analyzes the possible methods for performing laboratory work in chemistry during a situation of lockdown or pandemic. Laboratory practice is one of the main ways to learn the basics of science. The results of the experiments performed by the students stimulate their thinking, lead them to discussions and lead them to draw conclusions. All this leads to the optimization of the learning process. The use of very simple tools often helps in learning, facilitating the assimilation of the material. If the transfer of knowledge is not done correctly initially, then the subsequent understanding of the material will be more difficult to achieve. In the absence of a strong connection with previously studied topics it will be more difficult for students to think. Students begin to believe that science is difficult to understand, interest is often lost, and knowledge gained during the theoretical course may lose its value. People are naturally curious and always on the lookout, and the lab is a good place to satisfy that curiosity. In the laboratory, students have the opportunity to test their theoretical knowledge, which structures thinking and increases interest in science.
Studia Universitatis Moldaviae (Seria Ştiinţe Reale şi ale Naturii), Apr 1, 2008
GEOREVIEW: Scientific Annals of Stefan cel Mare University of Suceava. Geography Series, Apr 1, 2009
The Republic of Moldova has an enormous potential of exploiting the ecological agricultural and g... more The Republic of Moldova has an enormous potential of exploiting the ecological agricultural and genetic modified food products. Consumers, especially of EU market, have demanded both the conformity of products in regard to harmless effects and additional requirements for the quality. In this view, in the RM the Law on ecological agri-food products, 6 Governmental Decisions, 5 Presidential Decrees, 1 Ministerial Order and several standards were passed. The basic principles of ecological agrifood production have been proposed for adoption. Consumers, especially those on European Union markets, don't ask only the guarantees of confirmation of products and of harmlessness in consumption, but solicit additional confirmations concerning their quality, including ensurance that the products which they consume are pure ecological and genetic unmodified. For that reason, The Parliament of the Republic of Moldova adopted the law "Concerning ecological agrifood products" which anticipates settlement of social reports that are under to obtain ecological agrifood products without using the unending chemical substances, inclusively commercialization of ecological food products of vegetal and animal origin. Some general principles of ecological agrifood products were proposed.
Molecules
Sunflower oil (Helianthus annuus) contains a rich concentration of polyunsaturated fatty acids, w... more Sunflower oil (Helianthus annuus) contains a rich concentration of polyunsaturated fatty acids, which are susceptible to rapid oxidative processes. The aim of this study was to evaluate the stabilizing effect of lipophilic extracts from two types of berries, sea buckthorn and rose hips, on sunflower oil. This research included the analysis of sunflower oil oxidation products and mechanisms, including the determination of chemical changes occurring in the lipid oxidation process via LC-MS/MS using electrospray ionization in negative and positive mode. Pentanal, hexanal, heptanal, octanal, and nonanal were identified as key compounds formed during oxidation. The individual profiles of the carotenoids from sea buckthorn berries were determined using RP-HPLC. The influence of the carotenoid extraction parameters ascertained from the berries on the oxidative stability of sunflower oil was analyzed. The dynamics of the accumulation of the primary and secondary products of lipid oxidation ...
În articol sunt prezentate modele de situații didactice la disciplina școlară Chimia, prevăzute d... more În articol sunt prezentate modele de situații didactice la disciplina școlară Chimia, prevăzute de Regulamentul de atestare a cadrelor didactice din învățământul general, profesional tehnic și din cadrul structurilor de asistență psihopedagogică, aprobat prin ordinul Ministrului Educației, Culturii și Cercetării nr.1091din 07.10.2020. Sunt indicate și rezolvări ale acestor situații în conformitate cu algoritmul de prezentare din Regulament.
Universitatea Tehnică a Moldovei, 2020
The content of nitrates in foods of plant origin permanently comes into notice of consumers, soci... more The content of nitrates in foods of plant origin permanently comes into notice of consumers, society. Nitrates in large quantities are harmful to the human body, especially children. The legislation of the Republic of Moldova, which regulates the maximum acceptable limit (MAL) of nitrates, namely Government Decision No 115 on The control of nitrates in foods of plant origin, was brought into line with European legislation just in September 2020. In the present study, some aspects related to these normative changes were analyzed. It was determined that the vast majority of spinach samples from local agricultural market exceed 1.1-1.6 times the MAL of nitrates with reference to national legislation and 1.9-2.7 times concerning the legislation of the Russian Federation. Rucola practically falls within the limits established in the national legislation, the MAL being 6000 mg nitrate·kg-1 , but it exceeds by far (in 2.1 times) the MAL established in the Russian Federation. Fresh salad fa...
Food and Nutrition Sciences, 2021
The present study aimed to investigate the effectiveness of the use of some antioxidants-α-tocoph... more The present study aimed to investigate the effectiveness of the use of some antioxidants-α-tocopherol, n-octyl gallate, L-ascorbic acid 6-palmitate and matcha extract (green tea) as inhibitors of grape seeds, walnuts and corn germ oils oxidation. The oxidation was studied in a forced regime during 700 h, by the addition of hydrogen peroxide and Cu 2+ ions. The optimal conditions of the accelerated oxidation process in the analysed systems were established. The progress of lipid oxidation was evaluated by measuring the peroxide value (PV) and conjugated dienes and trienes (CD, CT). A series of secondary products of the lipid oxidation were identified: hexanal, octanal and hydroxy-nonadienal. The intensity of the formation of these compounds during oxidation was monitored. The results of this study showed that the oil samples with the addition of antioxidants showed considerably lower oxidation values compared to the control sample. More effective was the action of L-ascorbic acid 6-palmitate and n-octyl gallate, the optimum concentration was 0.1%. An inhibitory effect of the oxidation process was noted for αtocopherol and matcha extract, the optimal addition concentration was 1%.
Universitatea Tehnică a Moldovei, 2016
This article investigates the processes that take place during the forced thermooxidation of sunf... more This article investigates the processes that take place during the forced thermooxidation of sunflower oil. The results obtained in the study showed a major impact of thermo-oxidation. (90 ± 2 °C. supplied air with a speed of 8 ÷ 10 L·h-1 for 50 hours), on the physico-chemical indicators of the studied oil. The acidity index of fresh sunflower oil increased 13.7 times, with a value of 2.46 mg KOH·g-1 of fat for the thermo-oxidized oil compared to the initial value of 0.180 mg KOH·g-1 of fat. The thermo-oxidation of sunflower oil caused a significant decrease of the saponification index, which indicates a significant degree of polymerization and leads to viscosity increase of the studied sunflower oil. In order to highlight the impact of heat treatments, the analysis was performed by IR spectroscopy and the possible mechanisms of unsaturated fatty acids forced oxidation under the influence of thermal factor were analyzed. It was established that the applied treatment favoured both th...
Chemistry is an experimental science that is based on theoretical process and finds its applicati... more Chemistry is an experimental science that is based on theoretical process and finds its application in practical attempts in laboratory; it is based on experiment, as well as it is a method for scientific investigation, learning and evaluation. Having an experimental<br> character, chemistry can not be taught, learnt and evaluated without practical experiments. The experiment is a didactic method through which trained people have the purpose to carry out a chemical or physical process or phenomenon, or to modify their standard<br> conditions by introducing some new variables with the purpose to study them.
This paper is a didactic project to teach the topic "<em>Chemical bond and structure o... more This paper is a didactic project to teach the topic "<em>Chemical bond and structure of substance – didactic aspects</em>", that aims to help students understand the most important notions, laws and theories. In the process of mastering the material of the topic, skills should be improved for students to make inter-subject communications with physics and mathematics based on the application of knowledge about electrons, ions, and nucleus of an atom. Students should more often be given the opportunity to analyze the composition of substances and make conclusions about the nature of chemical bonds, compare the structure of atoms, simple and complex substances, establish a relationship with properties, and predict the type of crystal lattice based on the properties of substances, so they will be able to develop logical thinking skills. When studying the topic, ideas about the relationship of opposites, about the transition of quantitative changes to qualitative on...
The article analyzes the possible methods for performing laboratory work in chemistry during a si... more The article analyzes the possible methods for performing laboratory work in chemistry during a situation of lockdown or pandemic. Laboratory practice is one of the main ways to learn the basics of science. The results of the experiments performed by the students stimulate their thinking, lead them to discussions and lead them to draw conclusions. All this leads to the optimization of the learning process. The use of very simple tools often helps in learning, facilitating the assimilation of the material. If the transfer of knowledge is not done correctly initially, then the subsequent understanding of the material will be more difficult to achieve. In the absence of a strong connection with previously studied topics it will be more difficult for students to think. Students begin to believe that science is difficult to understand, interest is often lost, and knowledge gained during the theoretical course may lose its value. People are naturally curious and always on the lookout, and ...
The Republic of Moldova has an enormous potential of exploiting the ecological agricultural and g... more The Republic of Moldova has an enormous potential of exploiting the ecological agricultural and genetic modified food products. Consumers, especially of EU market, have demanded both the conformity of products in regard to harmless effects and additional requirements for the quality. In this view, in the RM the Law on ecological agri-food products, 6 Governmental Decisions, 5 Presidential Decrees, 1 Ministerial Order and several standards were passed. The basic principles of ecological agrifood production have been proposed for adoption. Consumers, especially those on European Union markets, don’t ask only the guarantees of confirmation of products and of harmlessness in consumption, but solicit additional confirmations concerning their quality, including ensurance that the products which they consume are pure ecological and genetic unmodified. For that reason, The Parliament of the Republic of Moldova adopted the law “Concerning ecological agrifood products” which anticipates settl...