amperometric method
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2021 ◽  
Vol 17 (5) ◽  
pp. 43-52
Author(s):  
A. A. Skhalyakhov ◽  
Kh. R. Siyukhov ◽  
Z. T. Tazova ◽  
L. V. Lunina

In the last decade the attitude of socially active people to their own health has changed significantly. The desire to lead a healthy lifestyle forms consumers’ demand for proper balanced nutrition, products enriched with natural biologically active substances of unconventional plant materials, systematic consumption of which can not only reduce the risk of alimentary diseases, but also protect a person from oxidative stress, which is the predecessor of many serious illnesses. Among the wide range of chemical compounds that make up plant materials, a special place is occupied by compounds of antioxidant action, such as flavonoids, phenol carboxylic acids, vitamins C and E. The aim of the research was to study the qualitative composition and quantitative content of natural antioxidants in some types of medicinal and technical plant materials of the Republic of Adygea to determine the possibility of their use in the production of functional food products. The content of biologically active compounds that determine the antioxidant properties of plant materials was determined using «Kapel 105 «M» capillary electrophoresis system and JASCO 875-UV liquid chromatograph. Antioxidant activity was measured by the amperometric method with Tsvet Yauza-01-AA analyzer. According to the results of the research, it has been found that Echinacea purpurea herb (1,09 g / dm3) and walnut leaves (0,96 g / dm3) exhibit a high antioxidant activity (in terms of gallic acid), which is due to the high concentration of natural antioxidants of the phenolic type. Due to these properties this plant raw materials can be used as enriching ingredients for the production of various groups of food products for functional purposes.


2021 ◽  
pp. 265-274
Author(s):  
Similla Leont'yevna Adzhiakhmetova ◽  
Nadezhda Mikhaylovna Chervonnaya ◽  
Dmitriy Igorevich Pozdnyakov ◽  
Eduard Tonikovich Oganesyan

This paper presents information on the total content of antioxidants, polysaccharides, micro and macro elements and amino acids of Ribes nigrum L. leaves. The purpose of this work is to study the chemical composition of Ribes nigrum L. leaves. The flavonoids were quantified spectrophotometrically, pectin substances gravimetrically, and the percentage of functional groups in pectin substances was carried out by the titrimetric method. The determination of the lipid-cholesterol blood profile of pectin substances isolated from of Ribes nigrum L. leaves was performed on 30 rats. The procedure for introducing solutions of the studied pectin substances and cholesterol solution were separated by a 2-hour interval. The total content of antioxidants was determined by amperometric method. The maximum content of antioxidants was revealed in the extraction of Ribes nigrum L. leaves, obtained by extraction with ethyl alcohol 50%. The content of water-soluble polysaccharides and pectin substances from of Ribes nigrum L. leaves is 2.17±0.06 and 9.91±0.28, respectively. The studied pectin substances belong to the group of low esterified pectins. The use of pectin substances from of Ribes nigrum L. leaves contributed to the correction of dyslipidemia. The sum of flavonoids in the analyzed object is 0.67±0.01%. The extraction of Ribes nigrum L. leaves obtained by extraction with purified water revealed aspartic and glutamic acids, alanine, proline, methionine and valine. Based on the data obtained, potassium predominates in the extraction from currants obtained by extraction with ethyl alcohol 70%. During the study, flavonoids, polysaccharides, amino acids, micro and macro elements of Ribes nigrum L. leaves were studied.


2021 ◽  
Vol 14 (9) ◽  
pp. 912
Author(s):  
Iulia Rus ◽  
Alexandra Pusta ◽  
Mihaela Tertiș ◽  
Cristina Barbălată ◽  
Ioan Tomuță ◽  
...  

The development of fast and easy-to-use methods for gemcitabine detection is of great interest for pharmaceutical formulation control in both research laboratories and hospitals. In this study, we report a simple, fast and direct electrochemical method for gemcitabine detection using a boron-doped diamond electrode. The electrochemical oxidation of gemcitabine on a boron-doped diamond electrode was found to be irreversible in differential pulse voltammetry, and scan rate influence studies demonstrated that the process is diffusion-controlled. The influence of the pH and supporting electrolytes were also tested, and the optimized differential pulse voltammetry method was linear in the range of 2.5–50 μg/mL, with a detection limit of 0.85 μg/mL in phosphate-buffered saline (pH 7.4; 0.1 M). An amperometric method was also optimized for gemcitabine detection. The linear range of the method was 0.5–65 μg/mL in phosphate-buffered saline of pH 7.4 as well as pH 5.5, the limit of detection being 0.15 μg/mL. The optimized differential pulse voltammetry and amperometric detection strategies were successfully applied to pharmaceutical formulations, and the results were compared to those obtained by high-performance liquid chromatography and UV-Vis spectrophotometry with good correlations.


Antioxidants ◽  
2021 ◽  
Vol 10 (7) ◽  
pp. 1121
Author(s):  
Liubov Skrypnik ◽  
Olga Babich ◽  
Stanislav Sukhikh ◽  
Olga Shishko ◽  
Svetlana Ivanova ◽  
...  

This study reveals that fossil shungite samples exhibit antioxidant activity, can reduce oxidized components, and bind to free radicals. A sample of Sh20 (size fraction—20 μm) (1.30 mg equivalents of ascorbic acid/g of shungite; 3.46 mg equivalents of trolox/g of shungite; 0.99 mg equivalents of quercetin/g of shungite) had the maximal activity according to the amperometric method. The obtained data indicate that shungite has antioxidant properties, but these are approximately 1000 times less pronounced than those of quercetin. A ShT20 sample (size fraction—20 μm + heat treatment) was found to have the highest antioxidant activity against the 2,2-diphenyl-1-picrylhydrazyl radical and cytotoxicity. Further studies, including the optimization of the antioxidant extraction conditions of shungite, and the analysis of the qualitative and quantitative composition of the obtained extracts, are required for a more accurate interpretation of the results. Shungite can be applied as an alternative to activated carbon in water purification, due to its absorption, catalytic, antioxidant, regenerating, and antibacterial properties, as well as its high environmental safety and relatively low cost. It is possible to identify new structural forms of carbon within, and other valuable properties of, shungite substance, which will make it possible to create effective technologies for the practical use of shungite rocks, particularly in the production of fullerenes and other carbon nanoclusters.


Author(s):  
Nadezhda Alekhina ◽  
Elena Ponomareva ◽  
Irina Zharkova ◽  
Andrej Grebenshchikov

Introduction. Various formulations of sprouted grain breads, including those with amaranth flour, were developed to combat food-related diseases. Healthy food industry requires thorough assessment procedures and hygienic practices. The research objective was to assess the functional properties and safety indicators of amaranth bread made from sprouted wheat grain. Study objects and methods. One day old grain bread was tested for antioxidant activity using amperometric method. Its glycemic index was determined according to the ratio of the area under the glycemic curve per bread sample to the area under the glycemic curve for pure glucose, expressed as a percentage. Crumb proteins digestibility was measured in vivo using ciliates Paramecium caudatum. Phytin content was measured by the colorimetric method, while safety indicators were compared to the Technical Regulations of the Customs Union No. 021/2011. Bound moisture content was determined with a refractometer after three days of storage according to the change in sucrose concentration. The number of mesophilic aerobic and facultative anaerobic microorganisms (NMAFAnM) was described based on State Standard 10444.15-94. Results and discussion. The amaranth flour slightly affected the antioxidant activity of the grain bread. It decreased the glycemic index by 8.3% and increased the microbiological purity by 1.4 times, raised the crumb proteins digestibility by 3.0%, reduced the phytin content by 7.0%, and slowed down the staleness process by 12 h. In terms of safety indicators, the obtained sample of amaranth grain bread met the TR CU 021/2011 requirements “On food safety”. The decrease in the glycemic index values could be explained by the lower activity of amylolytic enzymes in amaranth flour compared to sprouted wheat. The low digestibility of carbohydrates resulted from their effect on starch. The increase in digestibility and the decrease in phytin content were caused by the lower amount of dietary fiber. The high content of bound moisture explains the longer shelf life. Amaranth flour had lower microbiological contamination compared to wheat, which decreased the NMAFAnM. Conclusion. Amaranth flour had a positive effect on the functional properties of grain bread safety indicators, which makes it possible to include it into sprouted wheat grain products.


2021 ◽  
pp. 49-51
Author(s):  
Галина Андреевна Донская ◽  
Виктор Михайлович Дрожжин

Сохранение биологически активных компонентов молока является одной из главных задач научных работников и производителей молочных продуктов. Однако для выработки безопасного в санитарно-гигиеническом отношении продукта молоко от момента получения до реализации претерпевает различные термомеханические воздействия. При этом возможны нарушение оболочки жировых шариков, изменения массовой доли и структуры белка, минеральных солей, ферментной активности. В большей степени это происходит при гомогенизации. В процессе бактофугирования физико-химические показатели молока изменяются незначительно. Бактофугирование позволяет при щадящих температурных режимах снизить бактериальную обсемененность молока на 92-98 %. При этом удаляются анаэробные споры маслянокислых бактерий, что особенно важно для производства сыров. В связи с этим бактофугирование рекомендуют применять при производстве творога и творожных изделий, твердых сыров, где предусмотрены невысокие температуры пастеризации. Цель данной работы - изучение влияния бактофугирования на антиоксидантную активность молока. В задачи исследований входило определение физико-химических показателей и суммарного содержания водорастворимых антиоксидантов в сыром и бакто-фугированном молоке, получаемом с предприятия отрасли. После бактофугирования молоко термизировали и отправляли на производство сыров. Физико-химические показатели определяли стандартизованными методами, антиоксидантную активность - амперометрическим методом. Установлено, что титруемая кислотность, окислительно-восстановительный потенциал, массовая доля белка, содержание сухих веществ снижаются в бактофугированном и термизированном молоке в пределах 1,7-4,8 %. Содержание водорастворимых антиоксидантов уменьшается на 21-30 %. Preservation of biologically active components of milk is one of key goals of scientists and industry. However, to achieve required food safety, milk undergoes a number of thermomechanic steps when produced from from raw milk to end product. Often times this process is accompanied by breaking up of fat globule, alteration of mass weight and structure of proteins, mineral salts, enzymatic activity. Most of those occur during homogenization process. Bactofugation process has a minor impact on physico-chemical parameters of milk. When conducted at light temperatures, bactofugation allows to decrease bacterial contamination by 92-98 %. Anaerobic Butyric acid bacteria spores are removed which is of particular importance in cheese production. Therefore, bactofugation is recommended in production of curd and curd products, hard cheeses, processes with low pasteurization temperatures. The aim of this work was to study bactofugation impact on antioxidant activity of milk. Investigation scope included determination of physico-chemical parameters and total amount of water-soluble antioxidants in raw milk and after bactofugation. Followed by bactofugation, milk was heat treated and further utilized for cheese production. Physico-chemical parameters were determined by standard methods, antioxidant activity - by amperometric method. It was established that titrated acidity, redox potential, protein mass weight, and dry matter declined in milk after bactofugation and heat treatment with the range of 1.7-4.8 %. Water-soluble antioxidant composition was reduced by 21-30 %.


2021 ◽  
pp. 105-110
Author(s):  
F. A. Vagabova ◽  
G. K. Radjabov ◽  
A. M. Musaev ◽  
F. I. Islamova

Relevance, material and methods. Purpose of the work: comparative assessment of the content of the sum of phenolic compounds exhibiting antioxidant activity in various organs of herbaceous capers C. herbacea Willd. The 4 samples of C. herbaceawere collected from natural populations of Dagestan during the flowering and fruiting phases in the summer of 2019. The collected raw materials were divided into fractions (organs), dried in the shade to an air-dry mass, then subjected to further analysis to determine the total content of flavonoids, anthocyanins by the spertrophotometric method on SF-56; the total content of antioxidants by the amperometric method on the instrument of express analysis "Color-Yauza-001-AAA ".Results. During the analysis, good indicators were obtained for the content of the studied compounds. Thus, in terms of the content of flavonoids, the greatest variation is seen in the stems of herbaceous capers (0.34-0.86%) compared to their content in leaves and inflorescences (2.67-2.97% and 2.45-2.90%, respectively). The amount of anthocyanins varies in all organs within the range of 0.05-0.23%. The smallest spread is observed in the total content of antioxidants in the fruits of herbaceous capers (21.35-21.40 mg/l), while in inflorescences this indicator varies greatly (27.44-42.19 mg/l). It is noteworthy that the samples with a high value of antioxidants showed a low content of flavonoids, thereby indicating that flavonoids are not the main components in the antioxidant system of the studied caper species. An important condition determining the variability of the content of phenolic compounds in various plant organs is a complex of abiotic environmental factors. The study of this factor (altitude gradient) revealed a significant relationship with the accumulation of flavonoids in all organs, which has a multi-vector nature (correlation coefficient r*= 0.57; 0.56; -0.47), respectively, in stems, leaves, and inflorescences (P<0,05). A positive relationship in the accumulation of anthocyanins is observed with the height in caper leaves. In all other cases, the connection is random. In addition, the analysis of variance revealed that a large difference in the variability of the studied compounds is observed between individual groups of plants in the absence of intragroup variability.


Nanomaterials ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 171
Author(s):  
Supandeep Hallan ◽  
Maddalena Sguizzato ◽  
Markus Drechsler ◽  
Paolo Mariani ◽  
Leda Montesi ◽  
...  

The object of this study is a comparison between solid lipid nanoparticles and ethosomes for caffeic acid delivery through the skin. Caffeic acid is a potent antioxidant molecule whose cutaneous administration is hampered by its low solubility and scarce stability. In order to improve its therapeutic potential, caffeic acid has been encapsulated within solid lipid nanoparticles and ethosomes. The effect of lipid matrix has been evaluated on the morphology and size distribution of solid lipid nanoparticles and ethosomes loaded with caffeic acid. Particularly, morphology has been investigated by cryogenic transmission electron microscopy and small angle X-ray scattering, while mean diameters have been evaluated by photon correlation spectroscopy. The antioxidant power has been evaluated by the 2,2-diphenyl-1-picrylhydrazyl methodology. The influence of the type of nanoparticulate system on caffeic acid diffusion has been evaluated by Franz cells associated to the nylon membrane, while to evaluate caffeic acid permeation through the skin, an amperometric study has been conducted, which was based on a porcine skin-covered oxygen electrode. This apparatus allows measuring the O2 concentration changes in the membrane induced by polyphenols and H2O2 reaction in the skin. The antioxidative reactions in the skin induced by caffeic acid administered by solid lipid nanoparticles or ethosomes have been evaluated. Franz cell results indicated that caffeic acid diffusion from ethosomes was 18-fold slower with respect to solid lipid nanoparticles. The amperometric method evidenced the transdermal delivery effect of ethosome, indicating an intense antioxidant activity of caffeic acid and a very low response in the case of SLN. Finally, an irritation patch test conducted on 20 human volunteers demonstrated that both ethosomes and solid lipid nanoparticles can be safely applied on the skin.


2021 ◽  
Vol 1 (5) ◽  
pp. 86-96
Author(s):  
A. A. Savina ◽  
◽  
O. A. Voronina ◽  
L. P. Ignatieva ◽  
N. V. Bogolyubova ◽  
...  

The aim of the work was to study the component composition of milk of black-and-white cows in the winter-stall period and its main biochemical parameters. In this work, the total amount of water-soluble antioxidants (TAWSA) was assessed by the amperometric method (using "TsvetYauza 01-AA" device) and the average values of the milk component composition for four groups of cows, which were formed by the number of somatic cells (NSC) found in their milk. Milk of mastitis cows causes food poisoning that is why 1 groups were formed according to the NSC values: 200) less than 2 thousand units/ml, 200) from 499 to 3 thousand units/ml, 500) from 999 to 4 thousand units/ml and 1000) more than XNUMX thousand units/ml for milk samples of black-and-white cows of the Moscow region, which was used as raw material. The TAWSA values for 33 milk samples from cows in group 1 ranged from 6,80 to 27,91 mg/g (mean value 15,95±3,70 mg/g). The correlations between TAWSA and the following parameters of milk: mass fraction of fat (MFF) – 0,305; protein mass fraction true (PMF1) and total (PMF2) – 0,197 and 0,210; lactose – 0,156; dry fat-free milk residue (FFMR) – 0,276; total dry matter (TDM) – 0,399; freezing point (FP) – 0,112; pH – 0,114; the number of somatic cells (NSC) – (–0,052) are found. The TAWSA values for 15 milk samples from cows in group 2 ranged from 10,46 to 18,99 mg/g (average value 14,45±3,50 mg/g) are found. The correlations between TAWSA and the following parameters of milk: MFF – 0,332; PMF1 and PMF2 – 0,296 and 0,303; lactose – (–0,308); FFMR – 0,159; TDM – 0,391; FP – 0,226; pH – (–0,211); NSC – 0,193. The TAWSA values for 13 milk samples of cows in group 3 ranged from 10,46 to 18,99 mg/g (average value 16,04±3,60 mg/g) are found. The correlations between TAWSA and the following parameters of milk: MFF – (–0,352); PMF1 and PMF2 – (– 0,411) and (–0,401); lactose – (–0,166); FFMR – (–0,462); TDM – (–0,504); FP – (–0,766); pH – (–0,047); NSC – (–0,698). The TAWSA values for 12 milk samples from cows in group 4 ranged from 5,80 mg/g to 20,30 mg/g (average value 14,58±3,50 mg/g) are found. The correlations between TAWSA and the following parameters of milk: MFF – 0,159; PMF1 and PMF2 – 0,046 and 0,077; lactose – (–0,317); FFMR – (–0,237); TDM – 0,058; FP – (–0,036); pH – (–0,477); NSC – (–0,072) are found. These data obtained are of great importance both in assessing the physiological-biochemical status and the state of the antioxidant defense system of the cows' organism.


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