RESUMO
The aim of this study was to obtain drinking yogurts enriched with ACTICOA cocoa powder (ACTICOA), its extract (EACTICOA) and pure phenolics, as well as their inclusion complexes with cyclodextrins and alginate-chitosan (A-Ch) capsules, and to evaluate the effects of these additives on the viability of lactic acid bacteria (LAB) and antioxidant properties of fresh yogurts and yogurts stored for 14 days at 4 °C. The application of cocoa phenolic compounds in free form and in the form of EACTICOA to yogurts resulted in the greatest increase in the concentration of phenolic compounds and a significant improvement in the antioxidant properties of the fortified products. The highest TPC was found in yogurts enriched with free quercetin (107.98 mg CE/g). Yogurt fortified with free gallic acid showed the highest ability to neutralize free radicals (EC50 = 2.74 mg/mg DPPH, EC50 = 5.40 mg/mg ABTS) and reduce ferric ions (183.48 µM Trolox/g). The enrichment of yogurts with the tested phenolic compounds preparations, especially in the form of encapsulates, did not affect the viability of LAB during storage.
Assuntos
Antioxidantes , Cacau , Lactobacillales , Fenóis , Iogurte , Iogurte/microbiologia , Iogurte/análise , Antioxidantes/farmacologia , Antioxidantes/química , Fenóis/análise , Fenóis/farmacologia , Fenóis/química , Cacau/química , Lactobacillales/crescimento & desenvolvimento , Alimentos Fortificados/análise , Quitosana/química , Quitosana/farmacologia , Alginatos/química , Alginatos/farmacologia , Extratos Vegetais/farmacologia , Extratos Vegetais/química , CápsulasRESUMO
In the literature, there are few reports indicating hydrocolloids as a factor capable of reducing the amount of acrylamide formed in food. Therefore, the aim of the study was to examine the ability of soluble oat fiber to reduce the amount of acrylamide formed in the process of obtaining rusks. The effect of the concentration of ß-glucans in oat fiber preparations at 20% and 30% and the amount of preparations used at 10%, 15%, and 20% was investigated. On the basis of the obtained test results, it was shown that the most optimal concentration of oat fiber preparation in rusks recipe is at 15%, regardless of the content of ß-glucan in it. This concentration makes it possible to reduce the amount of acrylamide formed in baked goods and rusks by ~70% and ~60%, respectively, while maintaining the desired physical and chemical properties of the product. In addition, it was shown that the browning index and water activity strongly correlate with the content of acrylamide in rusks, which makes them good markers of this compound in rusks. The use of hydrocolloids in the form of oat fiber preparations with different contents of ß-glucan as a tool for reducing the amount of acrylamide in rusks, at the same time, offers the possibility of enriching these products with a soluble dietary fiber with health properties.
Assuntos
Pão , beta-Glucanas , Acrilamida , Avena , ColoidesRESUMO
This study investigated the properties of starch isolated from the unripe fruit of two apple cultivars (Malus domestica Borkh) grown in southern Poland (Central Europe). The chemical composition of both starches, molecular mass, their granulation, thermal characteristics, swelling characteristics, and rheological characteristics were studied. The starches differed significantly in ash, phosphorus, and protein content. The water-binding capacity at temperatures of 25-65 °C was similar, while differences of 20% appeared at higher temperatures. In contrast, a significant difference was found in the solubility of the two starches in the temperature range of 25-75 °C. The study showed that apple starches have a relatively low tendency to retrograde, with the enthalpy of gelatinization for starch from the Oliwka variety being 40% higher than that from the Pyros variety. However, the starches differed in the hardness of the gels formed, i.e., one variety formed soft gels with an internal structure resistant to external forces, while the other formed hard gels.
Assuntos
Malus , Amido , Malus/química , Amido/química , Indústria Alimentícia , Reologia , Solubilidade , Frutas/química , Temperatura , Peso Molecular , Água/químicaRESUMO
With the aim to obtain controlled-release systems and to preserve the antioxidant, immunomodulatory, and prebiotic activity of the bioactive compounds, microencapsulation of both honeydew honey and royal jelly into biopolymeric microparticles based on rye bran heteropolysaccharides (HPS) was successfully performed. Honeydew honey and royal jelly microcapsules were prepared by spray-drying method and were characterized in terms of morphology and biological properties. Due to the resistance of the obtained encapsulates to the acidic pH in the stomach and digestive enzymes, the microcapsules showed prebiotic properties positively influencing both the growth, retardation of the dying phase, and the pro-adhesive properties of probiotic bacteria, i.e., Bifidobacterium spp. and lactic acid bacteria. Moreover, as a result of fermentation of the microcapsules of bee products in the lumen of the large intestine, an increased synthesis of short-chain fatty acids, i.e., butyric acid, was found on average by 39.2% in relation to the SCFA concentrations obtained as a result of fermentation of native bee products, thus opening new perspectives for the exploitation of honeydew honey and royal jelly loaded microcapsules for nutraceutical applications.
Assuntos
Cápsulas , Microbioma Gastrointestinal , Mel , Prebióticos , Animais , Microbioma Gastrointestinal/efeitos dos fármacos , Abelhas , Ácidos Graxos Voláteis/metabolismo , Bifidobacterium/crescimento & desenvolvimento , Bifidobacterium/metabolismo , Fermentação , Probióticos , Ácidos GraxosRESUMO
Edible insects (Alphitobius diaperinus Panzer, Gryllus campestris, Tenebrio molitor, Chorthippus biguttulus) are rich in nutrients that potentially inhibit acetylcholinesterase (AChE), but also improve cognition. The aim of this study was to evaluate four varied species of freeze-dried edible insects (purchased from a store); their nutrient composition, including fat, total phenolic compounds, vitamins, and antioxidant properties; and the potential inhibitory effect of AChE. An additional goal was to obtain olive oil with the addition of edible insects. Such oil was characterized by high oxidizing properties and showed high affinity to AChE. The results showed that mealworms and grasshoppers had the highest content of fats (PUFA/SFA) and phenolic compounds. These insects also showed a high content of vitamins, which correlated with the highest affinity for AChE. Therefore, they were added as a functional additive to olive oil. Olive oil with the addition of edible insects showed a higher affinity for AChE and enriched the olive oil with vitamin C and B vitamins.
Assuntos
Insetos Comestíveis , Gafanhotos , Tenebrio , Animais , Azeite de Oliva , Acetilcolinesterase , Pós , VitaminasRESUMO
The nutritional value and health-promoting properties cause the fruits (acorns) of Quercus spp. to have great potential for use in the food industry as functional ingredients and antioxidants source. The aim of this study was to examine the bioactive compound's composition, antioxidant potential, physicochemical properties and taste characteristics of northern red oak (Quercus rubra L.) seeds subjected to roasting at different temperatures and times. The results indicate that the roasting markedly affects the composition of bioactive components of acorns. In general, the use of roasting temperatures greater than 135 °C causes a decrease in the total phenolic compound content of Q. rubra seeds. Furthermore, along with an increase in temperature and thermal processing time, a remarkable increase in melanoidins, which are the final products of the Maillard reaction, was also observed in processed Q. rubra seeds. Both unroasted and roasted acorn seeds had high DPPH radical scavenging capacity, ferric reducing antioxidant power (FRAP) and ferrous ion chelating activity. Roasting at 135 °C caused negligible changes in total phenolics content and antioxidant activity of Q. rubra seeds. Almost all samples had lower antioxidant capacity along with an increase in the roasting temperatures. Additionally, thermal processing of acorn seeds contributes to the development of the brown color and the reduction of bitterness, and the creation of a more pleasant taste of the final products. Overall, the results of this study show that both unroasted and roasted Q. rubra seeds may be an interesting source of bioactive compounds with high antioxidant activity. Therefore, they can be used as a functional ingredient of beverages or food.
Assuntos
Manipulação de Alimentos , Quercus , Manipulação de Alimentos/métodos , Antioxidantes/análise , Sementes/química , Reação de Maillard , Fenóis/análiseRESUMO
Type II topoisomerase (TOPII) is an enzyme that influences the topology of DNA. DNA breaks generated by TOPII may result in mutagenic or cytotoxic changes in cancer cells. In this study, we characterized interactions of TOPIIα with coffee extracts and individual chlorogenic acids (CHAs) from the extracts by performing isothermal titration calorimetry (ITC) and molecular docking (MD) simulations. The study showed that the highest affinity to TOPIIα was found in green coffee (ΔG = -38.23 kJ/mol) and monochlorogenic acids fraction of coffee extracts (ΔG = -35.80 kJ/mol), resulting from the high content of polyphenols, such as CHAs, which can bind to the enzyme in the active site. Coffee extracts and their fractions maintained a high affinity for TOPIIα after simulated digestion in the presence of probiotic bacteria. It can be concluded that coffee may be a potential TOPIIα inhibitor considered as a functional food for cancer prevention.
Assuntos
DNA Topoisomerases Tipo II , Polifenóis , Humanos , Polifenóis/farmacologia , Simulação de Acoplamento Molecular , Ácido Clorogênico/farmacologia , DigestãoRESUMO
Edible insects represent a new functional source of nutrients that can contribute to solving nutritional deficiency problems. The antioxidant potential and bioactive compounds of nut bars with the addition of three edible insects were evaluated. Acheta domesticus L., Alphitobius diaperinus P. and Tenebrio molitor L. flours were used. A 30% share of insect flour in the bars resulted in significantly greater antioxidant activity (TPC increased from 190.19 for standard bars to 309.45 mg catechin/100 g for bars with 30% addition of cricket flour). Insect flour contributed significantly to an increase in 2,5-dihydrobenzoic acid (from 0.12 for bars with a 15% share of buffalo worm flour to 0.44 mg/100 g in the case of bars with a 30% share of cricket flour) and chlorogenic acid in all bars (from 0.58 for bars with a 15% share of cricket flour to 3.28 mg/100 g for bars with a 30% addition of buffalo worm flour), compared to the standard. The highest content of tocopherols was found in bars with cricket flour, compared to standard bars (43.57 and 24.06 mg/100 g of fat, respectively). The dominant sterol in bars enriched with insect powder was cholesterol. The highest amount of it was found in cricket bars, and the lowest in mealworm bars (64.16 and 21.62 mg/100 g of fat, respectively). The enrichment of nut bars with insect flours raises the levels of valuable phytosterols in the final product. The addition of edible insect flours reduced the perception of most sensory attributes of the bars, compared to the standard bar.
Assuntos
Insetos Comestíveis , Tenebrio , Animais , Antioxidantes , Farinha/análise , Búfalos , Nozes , InsetosRESUMO
The aim of the study was to investigate the effects of microwave-assisted extraction (MAE) conditions (microwave power, extraction time, and ethanol concentration) on the efficiency of the extraction of phenolic compounds from selected plant species belonging to the genus Scutellaria (i.e., Scutellaria baicalensis and Scutellaria lateriflora). The extracts from selected Scutellaria species were examined to establish the total phenolic content and the in vitro antioxidant and anti-inflammatory activity. The antioxidant capacity was determined by the ferric reducing antioxidant power (FRAP) and 2,2,1-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging capacity methods. The anti-inflammatory activity was evaluated through the lipoxygenase (LOX) inhibitory assay. The phenolic profile of the extracts was characterized using ultra-high performance liquid chromatography coupled with diode array detection and high-resolution electrospray ionization mass spectrometry (UHPLC-DAD/ESI-HRMS/MS). Depending on the type of solvent and the extraction conditions used, the extracts obtained from selected Scutellaria species showed different total and individual phenolic content, as well as different antioxidant and anti-inflammatory properties. The results showed that all Scutellaria extracts had high total phenolic content and exhibited strong ferric ion reducing power and free radical scavenging capacity and a significant ability to inhibit the LOX activity. In general, the 70% ethanol extracts contained more phenolic compounds, mainly flavones, flavanones, and their derivatives, and showed greater in vitro biological activity than other extracts. The highest levels of phenolic compounds and the strongest antioxidant and anti-inflammatory potential were found in extracts from the roots of S. baicalensis. Optimal extraction conditions for all the plant materials tested were determined as the microwave power of 63 W, extraction time of 10 min, and 70% ethanol as the solvent.
Assuntos
Antioxidantes , Scutellaria , Antioxidantes/farmacologia , Antioxidantes/química , Micro-Ondas , Extratos Vegetais/farmacologia , Extratos Vegetais/química , Fenóis/química , Solventes/química , Etanol , Anti-Inflamatórios/farmacologia , Flavonoides/químicaRESUMO
The aim of this study was to verify various extraction methods: shaking water bath extraction (SWA), ultrasound-assisted extraction (UAE) and microwave assisted extraction (MAE), and their parameters to optimize the extraction yield as well as maximize the concentration of polyphenols in Plectranthus barbatus extracts. Extracts were obtained from dried roots of P. barbatus in various degrees of fragmentation and analyzed for content of polyphenols, antioxidant capacity and flavonoids. Additionally, phenolic compounds in extracts were analyzed using the UHPLC-DAD-ESI-MS/MS method. The conducted research showed that roots of P. barbatus are rich in polyphenolic compounds. A total of 15 phenolic compounds, belonging to the group of phenolic acids and their derivatives, were identified. The extraction yield was similar for all extraction methods and averaged 31%. Irrespective of the extraction method, the yield was the lowest in the case of using 80% ethanol as the solvent. The extracts obtained from the finer fraction were characterized by a higher antioxidant capacity as well as a higher concentration of polyphenolic compounds including flavonoids. UAE seems to be the most effective method for extraction of polyphenols from P. barbatus roots. Regardless of the extraction method, ethanol was a better extractant than distilled water. All ethanolic extracts were characterized by a high antioxidant capacity. The 80% ethanol solution was considered the best solvent for the extraction of flavonoids, while the 40% and 60% ethanol solutions were sufficient for the effective extraction of polyphenolic compounds in general.
Assuntos
Plectranthus , Antioxidantes/farmacologia , Antioxidantes/análise , Espectrometria de Massas em Tandem , Extratos Vegetais , Polifenóis , Flavonoides , Fenóis , Solventes , Etanol , ÁguaRESUMO
Six types of nut-based bars with the addition of edible insect flour were obtained. Flours made from three different insects (Tenebrio molitor L., Acheta domesticus L., Alphitobius diaperinus P.) were used at two different additive levels (15% and 30%) in relation to the weight of the nuts. The addition of insect flour significantly increased protein content and the insoluble fraction of dietary fiber. The largest amount of these compounds was found in bars with 30% cricket flour, 15.51 g/100 g and 6.04 g/100 g, respectively, in comparison to standard bars, 10.78 g/100 g and 3.14 g/100 g, respectively. The greatest consumer acceptance was found in relation to bars with buffalo worm flour. The overall acceptance of these bars was 6.26-6.28 points compared to 6.48 for standard bars. Bars and raw materials were characterized by the high biological value of the protein. Cis linoleic acid dominated among unsaturated fatty acids. The percentage of this compound was in the range of 69.56%, for bars with a 30% addition of buffalo worm flour, to 73.88%, for bars with 15% cricket flour. Instrumental analysis of taste and smell compounds showed the presence of compounds such as 3-methylbutanoic acid, hexanal, and 2,3-pentanedione.
Assuntos
Insetos Comestíveis , Tenebrio , Animais , Pós , Valor Nutritivo , Tenebrio/química , Farinha/análiseRESUMO
One tetracyclic antidepressant, mianserin hydrochloride (MIA), has quite significant side effects on a patients' health. Cyclodextrins, which are most commonly used to reduce the undesirable features of contained drugs within their hydrophobic interior, also have the potential to alter the toxic behavior of the drug. The present paper contains investigations and the characteristics of interaction mechanisms for MIA and the heptakis (2,6-di-O-methyl)-ß-cyclodextrin (DM-ß-CD) system, and evaluated the effects of the complexation on MIA cytotoxicity. In order to assess whether there was an interaction between MIA and DM-ß-CD molecules, isothermal titration calorimetry (ITC) have been chosen. Electrospray ionization mass spectrometry (ESI-MS) helped to establish the complex stoichiometry, and circular dichroism spectroscopy was used to describe the process of complex formation. In order to make a wider interpretative perspective, the molecular docking results have been performed. The viability of Chinese hamster cells were investigated in the presence of DM-ß-CD and its complexes with MIA in order to estimate the cytotoxicity of the drug and the conjugate with the chosen cyclodextrin. The viability of B14 cells treated with MIA+DM-ß-CD is lower (the toxicity is higher) than with MIA alone, and no protective effects have been observed for complexes of MIA with DM-ß-CD in any ratio.
Assuntos
Proliferação de Células/efeitos dos fármacos , Interações Medicamentosas , Efeitos Colaterais e Reações Adversas Relacionados a Medicamentos/patologia , Mianserina/toxicidade , beta-Ciclodextrinas/toxicidade , Animais , Células CHO , Cricetinae , Cricetulus , Efeitos Colaterais e Reações Adversas Relacionados a Medicamentos/etiologia , Antagonistas dos Receptores Histamínicos H1/toxicidade , Mianserina/metabolismo , Simulação de Acoplamento Molecular , beta-Ciclodextrinas/metabolismoRESUMO
In this study, the blueberries (BLUB), raspberries (RASB), blackberries (BLCB), pomegranates pomace (POME) and beetroots (BEET) freeze-dried powders were used as the sources of phenolic compounds to enrich different types of chocolates, substituting a part of the sweetener. It was found that 1% addition of fruit or vegetable powders to chocolates increased the content of total phenolic compounds (flavan-3-ols, phenolic acids and anthocyanins) of enriched dark and milk chocolates compared to the control ones dependent on the powder used. Among the enriched chocolates, the chocolates with the addition of BLUB powder were characterized by the highest total polyphenol content. The highest percentage increase (approximately 80%) in the total polyphenol content was observed in MCH chocolate enriched with BLUB powder. Chocolates incorporated with BLUB, RASB, BLCB and POME powders presented a richer phenolic compound profile than control counterparts. The highest DPPH radical-scavenging capacity was exhibited by the DCH98S chocolate enriched with BEET powder. However, the DCH98ESt chocolates enriched with POME and BEET powders demonstrated the highest FRAP values. An electronic nose analysis confirmed the existence of differences between the profiles of volatile compounds of various types of chocolates enriched with fruit or vegetable powders. Thus, the enrichment of dark and milk chocolates with BLUB, RASB, BLCB, POME and BEET powders seemed to be an interesting approach to enhance bioactivity and to enrich the sensory features of various chocolate types.
Assuntos
Antioxidantes/química , Chocolate , Antioxidantes/análise , Cacau/química , Liofilização , Frutas/química , PósRESUMO
Cocoa beans and their co-products are a rich source of beneficial compounds for health promotion, including polyphenols and methylxanthines. Knowledge of bioavailability and in vivo bioactivity of these phytochemicals is crucial to understand their role and function in human health. Therefore, many studies concerning bioavailability and bioactivity of cocoa bioactive compound have been done in both in vivo animal models and in humans. This critical review comprehensively summarizes the existing knowledge about the bioavailability and the major metabolic pathways of selected cocoa bioactive compounds (i.e. monomeric flavan-3-ols, procyanidins, anthocyanins, flavonols, phenolic acids, N-phenylpropenoyl-L-amino acids, stilbenes, and methylxanthines). The compiled results indicated that many of these compounds undergo extensive metabolism prior to absorption. Different factors have been suggested to influence the bioavailability of polyphenols and methylxanthines among them the role of gut microbiota, structure of these compounds, food matrix and occurrence of other substances were the most often considered. Aforementioned factors decided about the site where these bioactive compounds are digested and absorbed from the alimentary tract, as well as the pathway by which they are metabolized. These factors also determine of the type of transport through the intestine barrier (passive, involving specific enzymes or mediated by specific transporters) and their metabolic path and profile.
Assuntos
Produtos Biológicos/metabolismo , Produtos Biológicos/farmacocinética , Cacau/química , Cacau/metabolismo , Flavonoides/farmacocinética , Polifenóis/farmacocinética , Animais , Disponibilidade Biológica , Produtos Biológicos/química , Produtos Biológicos/isolamento & purificação , Flavonoides/isolamento & purificação , Flavonoides/metabolismo , Humanos , Polifenóis/isolamento & purificação , Polifenóis/metabolismoRESUMO
Due to the growing problem of obesity associated with type 2 diabetes and cardiovascular diseases, causes of obesity are extensively investigated. In addition to a high caloric diet and low physical activity, gut microbiota disturbance may have a potential impact on excessive weight gain. Some reports indicate differences in the composition of the intestinal microflora of obese people in comparison to lean. Bioactive compounds of natural origin with beneficial and multifaceted effects on the body are more frequently used in prevention and treatment of many metabolic diseases including obesity. Sideritis scardica is traditionally consumed as mountain tea in the Balkans to strengthen the body and improve mood. Many reports indicate a positive effect on digestive system, weight loss, and prevention of insulin resistance. Additionally, it exhibits antioxidant activity and anti-inflammatory effects. The positive effect of Sideritis scardica extracts on memory and general cognitive abilities is indicated as well. The multilevel positive effect on the body appears to originate from the abundant occurrence of phenolic compounds, especially phenolic acids in Sideritis scardica extracts. However, mechanisms underlying their action require careful discussion and further research. Therefore, the objective of this review is to summarize the available knowledge on the role and mechanism of action of biologically active compounds of Sideritis scardica and other related species from the genus Sideritis.
Assuntos
Antioxidantes , Doenças Metabólicas/tratamento farmacológico , Compostos Fitoquímicos/farmacologia , Extratos Vegetais/farmacologia , Polifenóis/farmacologia , Sideritis/química , Animais , HumanosRESUMO
Cocoa bean is a rich source of polyphenols, mainly flavonoids which have a wide range of biological properties. The aim of the study was to determine the physiological indices of laboratory rats as a response to diets containing water extracts of raw or roasted cocoa beans of Forastero variety, as well as purified monomeric flavan-3-ols fraction isolated from them. The influence of these extracts on selected parameters was studied during 4 weeks feeding. The samples of rats feces were collected throughout the experiment and after its completion, biological samples (intestines content, blood, and organs) were retrieved individually from each rat and subjected to analyses. The observed changes in the gastrointestinal tract functioning indices and metabolism indicators, determined throughout the study and after its completion, confirm to some extent the biological activity of polyphenol extracts of cocoa beans. The differences in the results obtained for the analyzed parameters of the gastrointestinal tract revealed that the cocoa bean extracts differently affected the physicochemical properties of rats' intestines. The results indicate the beneficial effects of the applied nutrition treatment on the activity of cecal enzymes and the content of volatile fatty acids in the gut.
Assuntos
Cacau/química , Fezes/química , Trato Gastrointestinal/química , Polifenóis/administração & dosagem , Animais , Dieta , Ácidos Graxos Voláteis/análise , Trato Gastrointestinal/efeitos dos fármacos , Metabolismo/efeitos dos fármacos , Extratos Vegetais/química , Polifenóis/química , Polifenóis/farmacologia , RatosRESUMO
Nanowires hold great promise as tools for probing and interacting with various molecular and biological systems. Their unique geometrical properties (typically <100 nm in diameter and a few micrometers in length) enable minimally invasive interactions with living cells, so that electrical signals or forces can be monitored. All such experiments require in situ high-resolution imaging to provide context. While there is a clear need to extend visualization capabilities to the nanoscale, no suitable super-resolution far-field photoluminescence microscopy of extended semiconductor emitters has been described. Here, we report that ground state depletion (GSD) nanoscopy resolves heterostructured semiconductor nanowires formed by alternating GaP/GaInP segments ("barcodes") at a 5-fold resolution enhancement over confocal imaging. We quantify the resolution and contrast dependence on the dimensions of GaInP photoluminescence segments and illustrate the effects by imaging different nanowire barcode geometries. The far-red excitation wavelength (â¼700 nm) and low excitation power (â¼3 mW) make GSD nanoscopy attractive for imaging semiconductor structures in biological applications.
RESUMO
The aim of the study was to identify and quantitatively assess of carotenoids and isoprenoid quinones biosynthesized by six different strains of acetic acid bacteria, belonging to genus Asaia, that are common beverage-spoiling bacteria in Europe. Bacterial cultures were conducted in a laboratory liquid culture minimal medium with 2% sucrose. Carotenoids and isoprenoid quinones were investigated using UHPLC-DAD-ESI-MS analysis. In general, tested strains of Asaia spp. were able to produce 10 carotenoids and 3 isoprenoid quinones: menaquinone-7, menaquinone-8, and ubiquinone-10. The main identified carotenoids in Asaia lannensis strains were phytofluene, neurosporene, α-carotene, while for Asaia bogorensis, neurosporene, canthaxanthin, and zeaxanthin were noted. What is more, tested Asaia spp. were able to produce myxoxanthophyll, which has so far been identified primarily in cyanobacteria. The results show that A. lannensis are characterized by statistically higher concentrations of produced carotenoids, as well as a greater variety of these compounds. We have noted that carotenoids were not only accumulated by bacterial cells, but also some strains of A. lannensis produced extracellular carotenoids.
Assuntos
Acetobacteraceae/química , Carotenoides/análise , Quinonas/análise , Espectrometria de Massas por Ionização por Electrospray , Vitamina K 2/análise , Zeaxantinas/análiseRESUMO
The antioxidant efficiency of 70% aqueous methanolic extracts from the leaves of twelve selected Cotoneaster Medik. species was evaluated using four complementary in vitro tests based on SET- (single electron transfer) and HAT-type (hydrogen atom transfer) mechanisms (DPPH, FRAP, O2(â¢-) and H2O2 scavenging assays). The samples exhibited the dose-dependent responses in all assays with activity parameters of EC50 = 18.5-34.5 µg/mL for DPPH; 0.9-3.8 mmol Fe(2+)/g for FRAP; SC50 = 27.7-74.8 µg/mL for O2(â¢-); and SC50 = 29.0-91.3 µg/mL for H2O2. Significant linear correlations (|r| = 0.76-0.97, p < 0.01) between activity parameters and total contents of phenolics (5.2%-15.4% GAE) and proanthocyanidins (2.1%-15.0% CYE), with weak or no effects for chlorogenic acid isomers (0.69%-2.93%) and total flavonoids (0.28%-1.40%) suggested that among the listed polyphenols, proanthocyanidins are the most important determinants of the tested activity. UHPLC-PDA-ESI-QTOF-MS analyses led to detection of 34 polyphenols, of which 10 B-type procyanidins, 5 caffeoylquinic acids and 14 flavonoids were identified. After cluster analysis of the data matrix, the leaves of Cotoneaster zabelii, C. splendens, C. bullatus, C. divaricatus, C. hjelmqvistii and C. lucidus were selected as the most promising sources of natural antioxidants, exhibiting the highest phenolic levels and antioxidant capacities, and therefore the greatest potential for pharmaceutical applications.
Assuntos
Antioxidantes/química , Extratos Vegetais/química , Polifenóis/química , Rosaceae/química , Antioxidantes/isolamento & purificação , Cromatografia Líquida de Alta Pressão , Flavonoides/química , Flavonoides/isolamento & purificação , Flavonoides/farmacologia , Sequestradores de Radicais Livres/química , Peróxido de Hidrogênio/química , Extratos Vegetais/farmacologia , Folhas de Planta/química , Polifenóis/isolamento & purificação , Polifenóis/farmacologia , Proantocianidinas/química , Proantocianidinas/isolamento & purificação , Proantocianidinas/farmacologia , Ácido Quínico/análogos & derivados , Ácido Quínico/química , Ácido Quínico/isolamento & purificação , Ácido Quínico/farmacologiaRESUMO
Polyphenols form the largest group of compounds among natural antioxidants, which largely affect the overall antioxidant and anti-free radical activity of cocoa beans. The qualitative and quantitative composition of individual fractions of polyphenolic compounds, even within one species, is very diverse and depends on many factors, mainly on the area of cocoa trees cultivation, bean maturity, climatic conditions during growth, and the harvest season and storage time after harvest. Thermal processing of cocoa beans and cocoa derivative products at relatively high temperatures may in addition to favorable physicochemical, microbiological, and organoleptic changes result in a decrease of polyphenols concentration. Technological processing of cocoa beans negatively affects the content of polyphenolic compounds.