Highest Values Of Antioxidant Activity Research Articles

Potentially functional lactose-free ice cream with Lacticaseibacillus casei CSL3, ginger, and honey.

To develop and characterize a functional lactose-free ice cream with added ginger and honey, evaluate the survival of Lacticaseibacillus casei CSL3 under frozen storage and the simulated gastrointestinal tract (GIT), as well as antioxidant activity and product acceptability. The survival of Lacticaseibacillus casei CSL3 was evaluated for 180 days, under frozen storage, and GIT at 60 days. At 15 days of storage, proximal composition, antioxidant activity, color, pH, acidity, fusion, density, overrun, and sensory analysis were performed. Ice cream was an effective food matrix for maintaining the viability of CSL3, with concentrations > 7 log CFU g- 1 during storage and GIT. In addition, the analysis showed overrun and prebiotic characteristics through high values of antioxidant activity and phenolic compounds, good acceptability, and purchase intention. The product has satisfactory market potential (acceptance rate of 95.19% and purchase intention rate > 96%), and it could become another means of inserting probiotics in food.

High nutritional value instant flakes produced from various cereal grains

The current study was carried out to prepare functional flakes from various cereals and to assess the nutritional value of breakfast cereal flakes and their sensory acceptability. Oat, soft wheat and durum wheat, barley (hull-less and hulled), triticale, millet and sorghum grains have been used. Physicochemical, functional, phytochemical properties and sensory evaluation were determined. The developed cereal flakes have high nutritional value and are high in dietary fiber. Concerning the overall acceptability of flakes, durum wheat, hull-less barley and triticale were more preferred than the other samples. Meanwhile, hulled barley and millet flakes showed the lowest scores compared with other flake samples due to the lowest score of their appearance and color. Triticale, durum wheat and hulled barley turned to be good alternatives for oat to prepare flakes of high-quality characteristics, as they have high protein (13.46, 11.92 and 11.67%, respectively) and ash contents along with low content of fat and low calories. In terms of nutritional quality, the results indicated that oat flakes were higher in Mg and P content, durum wheat flakes showed higher content of Mn, triticale had the highest content of K and Ca, and millet had the highest content of Zn and Fe. Triticale flakes showed significantly higher content of dietary fiber and water absorption index at room and hot temperatures when compared with other flakes. While comparing total phenolic content, the millet and barley flakes showed the highest values. Additionally, most flake samples had significantly higher values of antioxidant activity compared to oat flakes used as control samples.

The Antioxidant and Anti-Inflammatory Properties of Wild Bilberry Fruit Extracts Embedded in Mesoporous Silica-Type Supports: A Stability Study.

Polyphenolic extracts from wild bilberries (Vaccinium myrtillus L.) have shown antioxidant and anti-inflammatory effects, but they are prone to degradation when exposed to environmental factors, limiting their use in biomedical applications. To overcome this issue, this study proposed the embedding of wild bilberry fruit ethanolic extracts in pristine mesoporous silica functionalized with organic groups (mercaptopropyl and propionic acid), as well as coated with fucoidan, a biopolymer. Herein, we report a stability study of free and incorporated extracts in mesoporous silica-type supports in high-humidity atmospheres at 40 °C up to 28 days, using HPLC analysis, thermal analysis, and radical scavenging activity determination. Better chemical and thermal stability over time was observed when the extracts were incorporated in mesoporous silica-type supports. After 12 months of storage, higher values of antioxidant activity were determined for the extract embedded in the supports, silica modified with mercaptopropyl groups (MCM-SH), and fucoidan-coated silica (MCM-SH-Fuc) than that of the free extract due to a synergistic activity between the support and extract. All encapsulated extracts demonstrated remarkable effects in reducing NO production in LPS-stimulated RAW 264.7 cells. The treatment with extract embedded in MCM-SH-Fuc in a dose of 10 μg/mL surpassed the effect of free extract in the same concentration. For the extract encapsulated in an MCM-SH support, a lower IC50 value (0.69 μg/mL) towards COX-2 was obtained, comparable with that of Indomethacin (0.6 μg/mL). Also, this sample showed a higher selectivity index (2.71) for COX-2 than the reference anti-inflammatory drug (0.98). The developed formulations with antioxidant and anti-inflammatory properties could be further used in nutraceuticals.

Recovery of phenolic compounds from peach pomace using conventional solvent extraction and different emerging techniques.

The study compared high-pressure, microwave, ultrasonic, and traditional extraction techniques. The following extraction conditions were implemented: microwave-assisted extraction (MAE) at 900W power for durations of 30, 60, and 90s; ultrasonic-assisted extraction (UAE) at 100% amplitude for periods of 5, 10, and 15min; and high-pressure processing (HPP) at pressures of 400 and 500MPa for durations of 1, 5, and 10min. The highest yield in terms of total phenolic content (PC) was obtained in UAE with a value of 45.13±1.09mg gallic acid equivalent (GAE)/100g fresh weight (FW). The highest PC content was determined using HPP-500MPa for 10min, resulting in 40mg GAE/100g, and MAE for 90s, yielding 34.40mg GAE/100g FW. The highest value of antioxidant activity (AA) was obtained by UAE in 51.9%±0.71%. The PCs were identified through the utilization of Fourier transform infrared (FTIR) spectroscopy and high-performance liquid chromatography (HPLC). Utilizing multivariate analysis, the construction of chemometric models were executed to predict AA or total PC of the extracts, leveraging the information from IR spectra. The FTIR spectrum revealed bands associated with apigenin, and the application of HPP resulted in concentrations of 5.41±0.25mg/100g FW for apigenin and 1.30±0.15mg/100g FW for protocatechuic acid. Furthermore, HPLC analysis detected the presence of protocatechuic acid, caffeic acid, p-coumaric acid, and apigenin in both green extraction methods and the classical method. Apigenin emerged as the predominant phenolic compound in peach extracts. The highest concentrations of apigenin, p-coumaric acid, and protocatechuic acid were observed under HPP treatment, measuring 5.41±0.25, 0.21±0.04, and 1.30±0.15mg/kg FW, respectively.

Chemical Characterization and Antioxidant Activity of Apilarnil, Royal Jelly, and Propolis Collected in Banat Region, Romania

Bee products have a millennia-old tradition in human apitherapy, thanks to their numerous curative properties. The aim of this study was to perform a physicochemical characterization, including the percentage of water content, dry matter, pH, acidity, impurity content, protein, ash, and macro and micro minerals, and to evaluate the antioxidant activity of apiculture products, including apilarnil, royal jelly, and propolis. Samples were collected from our apiary in the Banat region of Romania in 2022 as well as from the market. Apilarnil and royal jelly were analyzed in pure and freeze-dried form, and propolis in pure and tincture form. Our results show that there is a large variability in the chemical composition and antioxidant activity of the three bee products studied, depending on the form of presentation and source of origin. In the case of commercial bee products, the best results were obtained in terms of chemical composition, including the content of macro and micro nutrients. All the samples analyzed showed acidity, pH, and impurity content values within the limits allowed by the quality standards. Apilarnil from our own apiary recorded the highest values for antioxidant activity, followed by propolis tincture and fresh propolis from own apiary.

The Comparison Of Bioactive Compounds Between Brewed and Extracted Robusta Coffee From West Lampung

Indonesia is ranked fourth highest in coffee production in the world. One type of coffee export commodity, namely Robusta coffee, is produced from the West Lampung region. Robusta coffee contains various bioactive compounds that act as antioxidants. This study aims to analyze the differences between brewed and extracted robusta coffee related to the bioactive compounds. The method used in this study began with coffee sample preparation, followed by brewing and ethanolic extracting the robusta coffee, measurement of TPC (total phenolic content in gallic acid equivalent), TFC (total flavonoid content in quercetin equivalent), and antioxidant activity using the DPPH method. The results showed that the TPC values were 11.27 mgGAE/g for brewed coffee and 61.98 mgGAE/g for extracted coffee, while the TFC values for brewed coffee were 11.99 mgQE/g and extracted coffee were 18.40 mgQE/g. The highest antioxidant activity value was obtained from extracted robusta coffee with an IC50 89.43 ppm which classified as strong enough antioxidant, while the antioxidant activity of brewed coffee has an IC50 218.74 ppm which classified as moderate antioxidant. TPC and TFC in this study showed a direct proportional relationship with antioxidant activity. The samples with the highest total phenolic and total flavonoid also exhibited the highest antioxidant activity.

Exploration of Phenolic Content and Antioxidant Potential from Plants Used in Traditional Medicine in Viesca, Mexico

The medicinal plants of the desert can be a potential source of natural bioactive compounds with applications in health and food preservation. This work aimed to investigate the phenolic content and antioxidant potential of twenty-three plants from the arid zone of Viesca, Mexico. The antioxidant potential was determined by three methods (ABTS, FRAP, and DPPH). Two extraction methods and three different concentration levels (1:10 mg/mL, 1:25 mg/mL, and 1:50 mg/mL) were evaluated. According to the results, Turnera diffusa (Damiana), Gutierrezia sarothrae (Hierba de San Nicolas), and Leucophyllum frutescens (Cenizo) present the largest content of phenolic compounds and high antioxidant activity. The highest values of antioxidant activity were achieved using a solid/liquid ratio of 1:50 g/mL for T. diffusa and G. sarothrae and 1:25 mg/mL for L. frutescens. The maceration method was the most suitable for extracting antioxidant compounds from T. diffusa and L. frutescens, while ultrasound-assisted extraction was more efficient for G. sarothrae. The HPLC-MS analysis showed the presence of important phenolic compounds. This study shows for the first time that three plants that naturally grow in Viesca have great potential as a source of natural antioxidant compounds.

Taxonomic, physicochemical, phenolic and antioxidant comparison in species of high Andean wild fruits: Rubus and Hesperomeles

Currently, humans are taking better care of their health. It is known that fruit consumption prevents degenerative diseases such as cancer and diabetes. On the other hand, the high Andean biodiversity is rich in various resources that have been undervalued up to now. In the present study, the botanical characterization, physical and chemical properties, phenolic compounds, and antioxidant capacity were compared in four non-climacteric high Andean wild fruits of the species Rubus (black siraca and red siraca) and Hesperomeles (pacra and capachu), collected in the Peru province of Andahuaylas, Apurimac region, between 3600 and 3900 m.a.s.l. The taxonomic identification was performed according to the catalog of angiosperms and gymnosperms by geographical location. Polyphenols were determined by the spectrophotometric method based on the use of the Folin–Ciocalteu reagent, and the antioxidant capacity by the DPPH reagent discoloration method. Data in triplicate were analyzed by a one-way analysis of variance (ANOVA) and a multiple-range test of least significant difference (LSD). The results showed significant differences (p < 0.05) in all properties studied. The maturity index and phenolic content directly affected the antioxidant capacity. The four wild fruits studied presented high values of polyphenols and antioxidant activity. Therefore, they should be considered in genetic improvement and field extension programs to promote their consumption, which would encourage healthy and nutritious eating.

Encapsulation and Biological Activity of Hesperetin Derivatives with HP-β-CD.

The encapsulation of insoluble compounds can help improve their solubility and activity. The effects of cyclodextrin encapsulation on hesperetin's derivatives (HHSB, HIN, and HTSC) and the physicochemical properties of the formed complexes were determined using various analytical techniques. The antioxidant (DPPH•, ABTS•+ scavenging, and Fe2+-chelating ability), cytotoxic, and antibacterial activities were also investigated. The inclusion systems were prepared using mechanical and co-evaporation methods using a molar ratio compound: HP-β-CD = 1:1. The identification of solid systems confirmed the formation of two inclusion complexes at hesperetin (CV) and HHSB (mech). The identification of systems of hesperetin and its derivatives with HP-β-CD in solutions at pHs 3.6, 6.5, and 8.5 and at various temperatures (25, 37 and 60 °C) confirmed the effect of cyclodextrin on their solubility. In the DPPH• and ABTS•+ assay, pure compounds were characterized by higher antioxidant activity than the complexes. In the FRAP study, all hesperetin and HHSB complexes and HTSC-HP-β-CD (mech) were characterized by higher values of antioxidant activity than pure compounds. The results obtained from cytotoxic activity tests show that for most of the systems tested, cytotoxicity increased with the concentration of the chemical, with the exception of HP-β-CD. All systems inhibited Escherichia coli and Staphylococcus aureus.

Myrtaceae leaves grown in Agroforestry: a sustainable alternative to producing natural antioxidants extracts

Myrtaceae species such as uvaia, grumixama, and feijoa have been used in Brazil’s Agroforestry Systems (AFS). In AFS, frequent pruning occurs, and leaves are discarded. However, the leaves contain specific phenolic compounds (PC) that, when appropriately extracted, produce extracts with antioxidant activity (AA). These extracts meet the demand for natural and sustainable food ingredients. Therefore, the drying study (40, 50, and 60 °C) of uvaia, grumixama, and feijoa leaves obtained from AFS was carried out, and the effect of drying on the PC profile (LC-ESI-MS/MS) and AA were evaluated. In the uvaia extracts, the major compounds were EGCG, gallic acid, and isoquercitin, accounting for 94% of their PC, and leaves dried at 50 °C promoted a better phenolic extraction. The gallic acid, 2.5 DHBA and isoqueticitrin represent 79% of the relative composition of PC in grumixama extracts, and leaves dried at 60 °C were the condition that allowed a greater extraction. While, epicatechin, catechin, gallic acid and isoquercitrin correspond to 66% of the PC composition of feijoa leaves. Grumixama had the highest values for AA by the FCRC and DPPH while feijoa had significant values for FRAP in all treatments. Dried leaves at 50 °C showed higher AA for all methods, except for grumixama which showed this behavior at 60 °C. These results indicate that these matrices proved promising sustainable sources of various phenolic compounds. The drying process of the leaves at 50 and 60 °C had a greater extraction of compounds with antioxidant activity, with potential industrial applications.

UJI ANTIOKSIDAN EKSTRAK ETANOL BIJI KOPI ARABIKA (Coffea arabica L.) LERENG GUNUNG ARGOPURA KABUPATEN JEMBER PADA BERBAGAI KONDISI PENYANGRAIAN

Coffee (Coffea arabica L.) is a plant which has been cultivated in Indonesia and it is one of natural source of antioxidants. The main bioactive component which contain antioxidant properties is chlorogenic acid. The roasting process can cause  chlorogenic acid in coffee beans to decrease as the temperature increases and the length of roasting, so the way coffee is served as a source of antioxidants which may need to be considered. The purpose of this study was to determine the group of compounds and antioxidant activity contained in Arabica coffee beans obtained from the slopes of Mount Argopura at various conditions of roasting. The samples of Arabica coffee beans each done roasting in advance at a temperature of 160°C - 180°C; 190°C - 210°C; and 220°C - 240°C before it is milled. The used of extraction method is maceration using 80% ethanol solvent. Antioxidant activity testing was done by DPPH method. Antioxidant activity is expressed based on the IC50 value (Inhibitor Concentration 50%). The highest value of antioxidant activity was obtained from Arabica coffee beans roasted at a moderate temperature with a value of IC50 26.41 ± 0.182 ppm. The result of the T-test obtained a sig value < 0.05 which indicates a difference in the antioxidant activity produced by the extract of Arabica coffee beans at various conditions of roasting.

Optimization and scale up of the enzymatic hydrolysis of Californian red worm protein (Eiseniafoetida)

Although the best-known use of the different species of earthworm is the production of organic fertilizer, they can also be considered a rich source of biologically and pharmacologically-active compounds, for use in the treatment of various diseases. In recent decades, with the development of biochemical technologies, research on the pharmaceutical effects of compounds extracted from different species of earthworms has begun. Enzymatic hydrolysis is the most common and widely used technique for producing bioactive hydrolysates, because it uses moderate operating conditions, with a certain specificity for the substrate. In the present study, the objective was to optimize and scale up the enzymatic hydrolysis of Eisenia foetida protein to obtain peptides with biological activity. The substrate characterization was carried out according to AOAC, a response surface design was performed for the optimization of the enzymatic hydrolysis and then the scaling was performed by means of dimensional analysis. The results show that the major component of the paste is protein, 65% of which is albumin, and the absence of pathogenic microorganisms was also found. Regarding optimization, it was found that the optimal hydrolysis conditions are achieved with pH = 8.5; temperature = 45 °C; amount of substrate = 125 g and volume of enzyme = 1245μL. For the scaling, 4 dimensionless pi-numbers were calculated which describe the process with no statistically significant differences between the model and the prototype; it can be concluded that the enzymatic hydrolysate of Eisenia foetida presents high values of antioxidant activity evaluated by different methodologies.

Evaluation of Antioxidant Properties of Commercial Pomegranate Juices

Background. Consumers consider pomegranate juice one of the most beneficial for health. The limited production of pomegranates in Russia cannot meet the needs of Russian consumers with juices of its own production. Pomegranate juices are produced from concentrates or pasteurized direct-squeezed juices imported from different countries, there is no information about their antioxidant properties.Purpose. Study of the content of the main biologically active substances and antioxidant activity of pomegranate juice of various brands on the consumer market, and their influence on the formation of antioxidant properties.Materials and Methods. The objects of research were freshly pressed juice from pomegranate fruits (control)and samples of commercial pomegranate juices produced using different technologies: «Grande», «Benature», «Grante» -direct-squeezed juice; «Swell», «O'keй», «Rich», «Gold Brand» - reconstituted pomegranate juice; «Nar» - reconstituted juice with the addition of direct-squeezed juice. In juices, the total content of phenolic compounds, anthocyanin, flavonoids, tannins and vitamin C was determined. The antioxidant activity of juices was determined by two methods: FRAP and coulometrictitration based on the measurement results of which the antioxidant index was calculated.Results. Juices of industrial production differed significantly in the amount of biologically active substances, the spread of values in their content between juices was 40-50%, they contained significantly less total anthocyanin and total flavonoids than freshly-pressed juice. Total tannins prevailed in the composition of phenolic compounds of all juices (40-75%). The antioxidant activity of juices varied depending on the method of determination. The FRAP test showed the highest values of antioxidant activity in the reconstituted pomegranate juice «Rich», and the coulometric titration showed the highest values in the direct-squeezed pomegranate juice «Benature». Juices had the highest antioxidant index Rich>Benature>Grante, the values of which were more than 85%. The antioxidant properties of pomegranate juices depend on the total amount of phenolic compounds (R2> 0.772) and total tannins (R2> 0.538).Conclusion. The formation of antioxidant properties of pomegranate juices depends on the amount of total phenolic compounds and total tannins. The results of the evaluation of the antioxidant properties of commercial pomegranate juices can be used in the development of functional beverages.

COMPARATIVE EVALUATION OF THE ANTIOXIDANT ACTIVITY OF MEDICINAL PLANTS IN THE PERM RE-GION

The paper considers the antioxidant properties of water and alcohol extractions of fermented and unfermented fireweed of the narrow-leaved fireweed family (Chamerion Angustifolium Onagraceae), St.), bitter wormwood (Artemisia absintium L.), red clover (Trifolium pratense). The effect of the fermentation process, solvent, and extraction time on antioxidant activity (AOA) was studied. A comparative assessment of the antioxidant properties of medicinal plants of the Perm region was carried out. Using the potentiometric method, it was found that the AOA values of water extracts of fireweed angustifolia increase with the time of extraction. Fireweed weakly fermented (finely ground) and fermented (finely ground) have the highest AOA values during extraction within 24 hours. Shoots of young fireweed angustifolia have very low AOA values compared to unfermented and fermented samples. The AOA of aqueous extracts of medicinal plants increases with the time of their extraction. Oregano has the highest AOA value – 2.78×10-2 mol-equiv, and red clover has the lowest value – 0.37×10-2 mol-equiv. The highest value of AOA among mixtures of medicinal plants has a mixture of oregano with fermented fireweed (finely ground) – 2.52×10-2 mol-equiv. It has been established that extracts prepared from 40% ethanol solution for fireweed angustifolia and 20 and 40% for oregano have the highest AOA values. The AOA values for the alcohol extract of oregano increase depending on the time of its extraction.

BIOLOGICALLY ACTIVE COMPOUNDS AND ANTIOXIDANT ACTIVITY OF THE PLANTS FROM THE MOUN-TAIN ALTAI OF THE CARAGANA GENUS

The article presents Data on the content of biologically active compounds (BAC) and the total phenolic antioxidants activity (TPA) evaluated for aboveground organs of three species from the Caragana Genus – C. bungei, C. pygmaea и C. spinosa, growing in the Mountain Altai. It was determined that leaves and reproductive organs contain flavonols, catechins, tannins, carotenoids, pectin substances. It is shown that biologically active substances of a plant are synthesized differently depending on the species, habitat and organ of the plant. The highest level of flavonols (36.4 мг/г), tannins (117.2 мг/г) and carotenoids (0.56 мг/г) was registered in leaves of C. spinosa. Catechins predominantly accumulated in the leaves of C. pygmaea (up to 211.3 mg/100g) and inflorescences of C. bungei (up to 205 mg/g). The content of pectin substances was quite high, with the biggest share of protopectins. The highest level of protopectins was registered in inflorescences of C. bungei (5.81%) and leaves of C. pygmaea (3.58%). Pectins are synthesized more in the flowers of C. bungei (0.74%) and leaves of C. spinosa (0.49%). The highest values of antioxidant activity were found in the water–ethanol extracts from the leaves of C. spinosa (1.61 mg/g), which is probably due to the increased content of flavonols and tannins. It was shown that the antioxidant activity of Caragana plants is 71% determined by the content of tannins, 62% by the content of flavonols and 41% by the content of carotenoids. C. spinosa is more promising for finding sources of antioxidants.

Polyphenol Iongel Patches with Antimicrobial, Antioxidant and Anti-Inflammatory Properties.

There is an actual need for developing materials for wound healing applications with anti-inflammatory, antioxidant, or antibacterial properties in order to improve the healing performance. In this work, we report the preparation and characterization of soft and bioactive iongel materials for patches, based on polymeric poly(vinyl alcohol) (PVA) and four ionic liquids containing the cholinium cation and different phenolic acid anions, namely cholinium salicylate ([Ch][Sal]), cholinium gallate ([Ch][Ga]), cholinium vanillate ([Ch][Van]), and cholinium caffeate ([Ch][Caff]). Within the iongels, the phenolic motif in the ionic liquids plays a dual role, acting as a PVA crosslinker and a bioactive compound. The obtained iongels are flexible, elastic, ionic conducting, and thermoreversible materials. Moreover, the iongels demonstrated high biocompatibility, non-hemolytic activity, and non-agglutination in mice blood, which are key-sought material specifications in wound healing applications. All the iongels have shown antibacterial properties, being PVA-[Ch][Sal], the one with higher inhibition halo for Escherichia Coli. The iongels also revealed high values of antioxidant activity due to the presence of the polyphenol, with the PVA-[Ch][Van] iongel having the highest activity. Finally, the iongels show a decrease in NO production in LPS-stimulated macrophages, with the PVA-[Ch][Sal] iongel displaying the best anti-inflammatory activity (>63% at 200 µg/mL).

THE PHENOLIC COMPOUNDS CONTENT AND ANTIOXIDANT ACTIVITY OF SOME MEDICINAL PLANTS

In the present study, the infusions from six medicinal plants have been evaluated in terms of their polyphenols content and antioxidant activity. The plants selected for this study are the following: elder (Sambucusnigra), chamomile (Chamomillaegermanicaeflos), sage (Salvia officinale), mistletoe (Viscum album), lemon balm (Melissa oficinalis), lavender (Lavandula angustifolia). The investigated samples show a wide variation in the values obtained both for the antioxidant capacity and for the content of total phenolic compounds. The values obtained for the content of phenolic compounds vary between 87.93 μg gallic acid equivalent/mL (mistletoe) and 984.33 μg gallic acid equivalent/mL (chamomile) and increase in the order of mistletoe < chamomile < lavender < sage <elder < lemon balm. All investigated samples show high values of antioxidant activity against the DPPH radical. The results indicate the highest antioxidant activity for lemon balm. The values vary between 1.05 and 14.63 μM Trolox equivalent /mL infusion and decrease in the order: lemon balm, sage, lavender, elder, chamomile, mistletoe. The high content of phenolic compounds of these medicinal plants can explain their use in the therapy of many disease.

SYNTHESIS AND PRECLINICAL STUDY OF ANTIOXIDANT ACTIVITY OF [1,2,4]TRIAZOLO[1,5-A]PYRIDINE DERIVATIVES

Purpose. Synthesis and study of antioxidant properties of [1,2,4]triazolo[1,5-a]pyridine derivatives and their potential toxicity using preclinical diagnostic methods. Methodology. Derivatives of [1,2,4]triazolo[1,5-a]pyridine were synthesized on the basis of 2-aminopyridines and ethyl isothiacyanatocarbonate, with subsequent cyclization of intermediate adducts. The resulting 2-amino[1,2,4]triazolo[1,5-a]pyridines were reacted with isoamyl nitrite in the presence of CuHal2, which led to the synthesis of volatile 2-halogeno[1,2,4]triazolo[1,5- a]pyridine. The toxicity of the obtained compounds was studied by the degree of hemolysis of erythrocytes in a hypotonic NaCl solution. The intensity of free-radical oxidation of lipids was assessed spectrophotometrically by the formation of TBА-active products. The antioxidant activity of the substances was determined by inhibiting the oxidation of adrenaline under conditions of artificial oxidative stress. Scientific novelty. For the first time, the antioxidant activity of the [1,2,4]triazolo[1,5-a]pyridine derivatives described in the paper was investigated and their toxicity was studied according to the degree of hemolysis of erythrocytes in a hypotonic NaCl solution. Conclusions. The in vitro cytotoxicity study model showed that compounds 5a and 5b, which contain bromine atoms in the 2, 5, and 7 positions of the pyridinotriazole heterosystem, exert the greatest influence on the stability of erythrocyte membranes. The study of antioxidant activity showed that the highest values of antioxidant activity are characteristic of compounds of the 4a-d series, namely compounds 4b and 4c, which are characterized by the presence of an amino group in the 2nd position and the presence of a bromine atom as a substitute in the 1st and 5th positions of the pyridine fragment of the heterosystem. The dynamics of antioxidant activity on the model of inhibition of adrenaline oxidation confirms the opinion about the lowest toxicity and the highest ability to inhibit the formation of reactive oxygen species of compounds 4b and 4c (40.16 and 38.82% relative to ionol). So, with the use of preclinical diagnostic methods, we proved the presence of physicochemical activity in a number of investigated compounds. 2-amino-[1,2,4]triazolo[1,5a]pyridine derivatives with a bromine atom as a substitute in the pyridine fragment of the molecule should be considered as potential antioxidants in the future, and the studied condensed system can be considered a promising heterocyclic framework for creating potential antioxidant agents.

Depolanma Sırasında Sıcaklık ve Paketleme Yönteminin Dondurarak Kurutulmuş Kırmızı Pancar Tozunun Biyoaktif Bileşenleri Üzerine Etkisi

In this study, the effect of two different storage temperatures (4 and 25°C) and two different packaging techniques (normal atmosphere (NAP) and modified atmosphere (MAP)) on some quality properties of freeze-dried red beet powder during storage for 28 days. Color, total phenolic content, total antioxidant activity and betanin analyses were performed weekly during storage. The L*, a*, b*, chroma and hue angle values of all samples stored at low temperature and room temperature decreased during storage while their ΔE values increased. At the end of the storage, a loss between 1.20 and 2.30% occurred in the total phenolic contents of powder samples. The highest antioxidant activity value was determined in MAP samples stored at low temperature, and the lowest antioxidant activity value in NAP samples stored at room temperature. Losses in the betanin contents of NAP and MAP samples stored at room temperature were 12.02 and 10.14%, respectively. In samples stored at low temperature, their loss rates were 2.03 and 0.81%, respectively. In general, the storage condition in which the bioactive compounds of freeze-dried red beet powder suffered the least loss was at low temperature and in samples packaged with a MAP technique.

Assessment of the bioavailability of flavonoids in herbal beverages with antioxidant properties

Relevance. The development of fermented herbal beverages will make it possible not only to process grain crops as efficiently as possible, but also to meet the needs of people with intolerance to milk components, as well as those who adhere to a vegetarian diet. As one of the directions, it is possible to offer production of fermented vegetable drinks with predetermined properties by enriching them with antioxidants of polyphenolic nature. These technologies will minimise the risks of non-communicable diseases in the Russian Federation and stabilise public health in the long term.Methods. Six samples of fermented herbal beverages were identified as objects of study, two of which were obtained by fermentation of wheat and barley grains using "Bifivit" starter, powdered flavonoid taxifolin was added to other two samples at the fermentation stage, while the last two used the hydroxypropyl-betacyclodextrin encapsulated form of taxifolin. Total flavonoid content using spectrophotometric method, antioxidant activity(AOA) using DPPH-method as well as bioavailability index and digestibility criterion were determined in all tested samples.Results. All the samples of fermented herbal beverages with taxifolin are characterized by sufficiently high flavonoid content. The samples containing encapsulated forms of the flavonoid have, on average, 7 to 8% lower values than the samples of herbal drinks containing the native form of the flavonoid. At the same time, the bioavailability index for the samples containing encapsulated forms of flavonoid was on average 40 to 42% higher, indicating the effectiveness of the encapsulation process. The highest values of antioxidant activity were characteristic of the plant drinks enriched with the initial form of taxifolin, which is probably due to the creation of a protective shell and a decrease in the AOA values by 10–12% on average in samples with encapsulated form. The process of fermentation of vegetable raw materials leads to an increase in their digestibility, as evidenced by the growth of the infusoria Tetrahymena pyriformis. Introduction of taxifolin into the formulation of drinks both in its original and encapsulated form increases the growth of protozoa by 187±4–315±3%.