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Antioxidant properties of extracts from buckwheat by-products
Marzanna H??,Danuta Górecka,Krzysztof Dziedzic
Acta Scientiarum Polonorum : Technologia Alimentaria , 2012,
Abstract: Background. In the course of production of buckwheat groats by-products are produced, such as bran and hull, which apart from high content of dietary fi ber, may also constitute valuable sources of antioxidants. The aim of these investigations was to determine the antioxidant activity of extracts from by-products produced during processing of buckwheat for groats. Material and method. Analyses were conducted on bran and hull of buckwheat cv. Kora. Extraction was run using acetone, methanol and water at room temperature for 24 h. The level of phenolics was determined spectrophotometrically with the Folin-Ciocalteau reagent, using (+) catechin as a standard. Antioxidant activity of extracts was analysed in relation to linoleic acid, running incubation for 19 h, by scavenging of stable radicals of DPPH (2,2-diphenyl-1-picrylhydrazyl) and on the basis of metal chelating ability. Recorded results were compared with the activity of BHT (butylated hydroxytoluene). Results. The highest content of polyphenols was found in the methanol extract of hull (168.5 mg/g d.m.), which was also characterised by the best antiradical properties. The lowest content of total phenols was found for water extracts of bran after grinding and fi nal bran, at 20.3 mg/g d.m. and 10.2 mg/g d.m. In the emulsion system the highest activity was found for methanol extracts of hull and bran after grinding (Wo = 0.89), as well as the extract of fi nal bran (Wo = 0.85). A higher chelating ability in relation to Fe (II) ions was observed for bran extracts (after grinding – 76.1%, fi nal bran – 62.2%) than for hull extracts (26%). Conclusions. Extracts obtained from by-products of buckwheat were characterised by high antioxidant activity in the applied model systems.
Antioxidant activity of wheat and buckwheat flours  [PDF]
Sedej Ivana J.,Saka? Marijana B.,Mi?an Aleksandra ?.,Mandi? Anamarija I.
Zbornik Matice Srpske za Prirodne Nauke , 2010, DOI: 10.2298/zmspn1018059s
Abstract: Antioxidative activities of wheat flours (type 500 and wholegrain) and buckwheat flours (light and wholegrain) were tested using 1,1-diphenyl-2-picrylhydrazyl (DPPH·)-scavenging activity, reducing power and chelating activity on Fe2+. Also, the content of the total phenolics of ethanolic extracts was estimated. Polyphenolics content (expressed as gallic acid equivalent, GAE) in wheat flours varied between 37.1 and 137.2 μg GAE/g extract, while its content in buckwheat flour were at least four time higher and ranged between 476.3 and 618.9μg GAE/g extract. Ethanolic extracts of buckwheat flours exhibited higher antioxidant activities in all the assays, except for chelating activity. Regarding all the obtained results, it can be concluded that bakery products produced with buckwheat flour could be regarded as potential functional foods.
Antimycotic and Antifungal Activities of Amaranth and Buckwheat Extracts  [PDF]
Silvia Mosovska,Lucia Birosova
Asian Journal of Plant Sciences , 2012,
Abstract: Nowadays, there has been an increased interest in various natural plants as a source of biological active compounds including polyphenols. Important sources of these phytochemicals are less known pseudocereals such as amaranth and buckwheat. The objective of this study was determination of antimycotic and antifungal effects of mentioned pseudocereals. Antimicrobial screening against selected three yeast strains and four strains of fungi was carried out on DMSO buckwheat and amaranth extracts prepared by alkali hydrolyses. Results suggested variation in the antimicrobial properties of tested extracts. The studied extracts suppressed growth of Aspergillus flavus, Fusarium culmorum and Alternaria alternata. No inhibitory effect was observed against Rhizopus oryzae and tested yeast.
Evaluation of the biological activity of sunflower hull extracts
Taha, F. S.,Wagdy, S. M.,Hassanein, M. M.M.,Hamed, S. F.
Grasas y Aceites , 2012, DOI: 10.3989/gya.072111
Abstract: This work was planned with the aim of adding value to sunflower seed hulls, a waste product of the oil industry by preparing a sunflower hull phenolic extract rich in chlorogenic acid (CGA). In order to fulfill this goal, the optimization for the extraction of a phenolic extract from the hulls was investigated. The parameters studied were: type of solvent, solvent to water ratio and hull to solvent ratio. In addition, the solvent mixtures were also studied. The resulting phenolic extracts were evaluated for their biological activities. This included phenolic content determination, evaluation of the antioxidant and antimicrobial activities. Chlorogenic acid was determined in two chosen hull extracts using the UV spectrophotometric method and HPLC analysis. The anticarcinogenic activity of the two chosen extracts was tested on seven different cell line carcinomas. The results revealed that all the phenolic extracts of sunflower hull studied contain between 190-312.5 mg phenolics/ 100 g hulls. The highest phenolic extraction was achieved with 80% methanol (1:30, hull to solvent, w/v ratio) and methanol to ethanol to water (7:7:6 v/v/v) mixture with values of 312.5 and 306.5 mg phenolics/100 g hulls, respectively. The free radical scavenging activity and antioxidant activity of all the samples ranged from 33.6-72.6%. The highest antioxidant activity and free radical scavenging activity were achieved by the same extracts that possessed the highest phenolic content, namely methanol to ethanol to water extract and 80% methanol with values 71.8 and 72.6%, 68.2 and 70.9% respectively, compared to 77.9 and 76.9% respectively for TBHQ. All the phenolic extracts possessed antimicrobial activity but to different levels against different pathogenic bacteria. The two chosen extracts also possessed anticarcinogenic activity, which differed among varying cell line carcinomas. The HPLC analysis indicated that chlorogenic acid was the main phenolic acid in the extract. Thus it can be concluded that sunflower hull is a potential source of nutraceuticals. Este trabajo fue planificado con el objetivo de agregar valor a un producto de desecho de la industria aceitera, como es la cáscara de girasol, mediante la preparación de un extracto fenólico rico en ácido clorogénico (CGA). Para cumplir con este objetivo, se investigó la optimización de la extracción del concentrado fenólico de las cáscaras. Los parámetros estudiados fueron: tipo de disolvente, relación disolvente: agua y la relación cáscara:disolvente. Además, también se ha estudiado el uso de diferentes mezclas de disolv
Bioactivity comparison of extracts from various parts of common and tartary buckwheats: evaluation of the antioxidant- and angiotensin-converting enzyme inhibitory activities
Hweiyan Tsai, Hweiwen Deng, Shangheng Tsai, Yahsien Hsu
Chemistry Central Journal , 2012, DOI: 10.1186/1752-153x-6-78
Abstract: The extract of common hulls extracted using 50% (v/v)-ethanol solvent presented a remarkable inhibitory activity. The value of IC50 is 30 μg ml-1. The extracts of both common and tartary hulls extracted using 50% (v/v)-ethanol solvent demonstrated an antioxidant activity that is superior to that of other extracts.This study determined that the ethanolic extract of the hulls of common buckwheat presented more favorable antioxidant and ACE inhibitory abilities. However, the correlation of antioxidant activity and ACE inhibitory activity for all 18 types of extracts is low. The ACE inhibitory activity could have been caused by a synergistic effect of flavonoids or from other unidentified components in the extracts. The ethanolic extract of common hulls demonstrated remarkable ACE inhibitory activity and is worthy of further animal study.Food is not only a source of energy and nutrition for maintenance and growth of the body but is also a source of bioactive compounds that have beneficial effects on humans. For example, common buckwheat (Fagopyrum esculentum) and tartary buckwheat (Fagopyrum tataricum) are traditional foodstuffs available worldwide. They are also essential as functional food resources because of the high polyphenol and mineral contents in the seed. Numerous previous studies have discussed the antioxidant properties of buckwheat flour and buckwheat sprouts [1-12]. Campbell [13] reported that buckwheat comprises 3 classes of flavonoids: flavonols, anthocyanins, and C-glucosyl-flavones. ACE-inhibitory activity of flavonoids isolated from other plants has been reported previously [14,15]. The only reports existent were of dipeptides from buckwheat flour displaying inhibitory activity for the angiotensin-I converting enzyme [16-18]. No information is available regarding the inhibitory activity of angiotensin-I converting enzymes in other parts of the buckwheat plant. From an agricultural perspective, identifying an alternative approach for using the entire b
Phenolics Content and Antioxidant Activity of Tartary Buckwheat from Different Locations  [PDF]
Xu-Dan Guo,Yu-Jie Ma,John Parry,Jin-Ming Gao,Liang-Li Yu,Min Wang
Molecules , 2011, DOI: 10.3390/molecules16129850
Abstract: Two tartary buckwheat samples (Xingku No.2 and Diqing) grown at three locations were analyzed for free and bound phenolic content and antioxidant properties. Moreover, the relative contributions of variety and growing environment to phenolic content and antioxidant properties were determined, as well as correlations of these properties to growing conditions. The total phenolic contents varied from 5,150 to 9,660 μmol of gallic acid equivalents per 100 gram of dry weight (DW) of tartary buckwheat and the free phenolics accounted for 94% to 99%. Rutin content was in the range from 518.54 to 1,447.87 mg per 100 gram of DW of tartary buckwheat. p-Hydroxybenzoic, ferulic and protocatechuic acids were the prominent phenolic acids and other phenolics, including p-coumaric, gallic, caffeic, vanillic and syringic acids were also detected. Tartary buckwheat exhibited higher DPPH· and ABTS·+ scavenging activities and was more effective at preventing the bleaching of β-carotene in comparison with reference antioxidant and plant phenolics constituents. Additionally, growing conditions and the interaction between variety and environment may have more contribution than variety to individual phenolics and antioxidant properties of tartary buckwheat. Environmental parameters such as higher altitudes may also have an increasing effect on rutin and phenolic acids. This study suggests that tartary buckwheat has potential health benefits because of its high phenolic content and antioxidant properties. These components could also be enhanced by optimizing the growing conditions of a selected variety.
Aldose reductase inhibitory activity and antioxidant capacity of pomegranate extracts
imen Karasu, Ahmet Cumao lu, Ali Rifat Gúrpinar, Murat Kartal, Lucia Kovacikova, Ivana Milackova, Milan Stefek
Interdisciplinary Toxicology , 2012, DOI: 10.2478/v10102-012-0003-8
Abstract: The pomegranate, Punica granatum L., has been the subject of current interest as a medicinal agent with wide-ranging therapeutic indications. In the present study, pomegranate ethanolic seed and hull extracts were tested, in comparison with a commercial sample, for the inhibition of aldose reductase, an enzyme involved in the etiology of diabetic complications. In vitro inhibition of rat lens aldose reductase was determined by a conventional method. Pomegranate ethanolic hull extract and commercial pomegranate hull extract exhibited similar aldose reductase inhibitory activity characterized by IC50 values ranging from 3 to 33.3 μg/ml. They were more effective than pomegranate ethanolic seed extract with IC50 ranging from 33.3 to 333 μg/ml. Antioxidant action of the novel compounds was documented in a DPPH test and in a liposomal membrane model, oxidatively stressed by peroxyl radicals. All the plant extracts showed considerable antioxidant potential in the DPPH assay. Pomegranate ethanolic hull extract and commercial pomegranate hull extract executed similar protective effects on peroxidatively damaged liposomal membranes characterized by 10 < IC50 < 100 μg/ml. Pomegranate ethanolic seed extract showed significantly lower antioxidant activity compared to both hull extracts studied. Pomegranate extracts are thus presented as bifunctional agents combining aldose reductase inhibitory action with antioxidant activity and with potential therapeutic use in prevention of diabetic complications.
Contents of selected bioactive components in buckwheat groats
Danuta Górecka,Marzanna H??,Krystyna Szymandera-Buszka,Krzysztof Dziedzic
Acta Scientiarum Polonorum : Technologia Alimentaria , 2009,
Abstract: Background. Nutritive value of food is determined by its content of basic nutrients essential for the proper functioning of the human organism. Buckwheat grain is one of the most valuable raw materials for production of groats as well as functional food. It is characterized by high contents of starch, protein as well as dietary fibre. Apart from the above mentioned nutrients, buckwheat groats contain flavonoid compounds, playing the role of antioxidants. The aim of this study was to determine contents of dietary fibre and its fraction composition, thiamine and phenolic compounds in roasted buckwheat groats, as well as antioxidant properties of ethanol buckwheat groats extracts. Material and methods. Experimental material comprised roasted buckwheat groats purchased at a grocery shop. Contents of neutral detergent dietary fibre (NDF) and its fractions were determined by the detergent method according to Van Soest. Thermostable a-amylase (Termamyl 120 L) was used in the digestion of starch. Contents of total dietary fibre (TDF), soluble dietary fibre (SDF) and insoluble dietary fibre (IDF) were determined according to Asp et al. The content of thiamine was determined by the thiochrome method. Total polyphenol content was determined by colorimetry according to the Folina-Ciocalteu method. Antioxidant properties of extracts were estimated based on the capacity of extracts to scavenge the DPPH radical (1,1-diphenyl-2 picrylhydrazyl) and towards linolic acid. The capacity to inhibit self-oxidation of linolic acid was determined according to Lingnert et al. Results. The NDF and TDF contents in buckwheat groats, amounting to 5.63 and 8.4%, respectively. The fraction found in biggest amounts was the hemicellulose fraction (3.42%). The level of the IDF fraction was much higher (5.94%) than that of SDF (2.46%). Thiamine content was 0.519 mg/100 g product, while the total content of phenolic compounds extracted from buckwheat groats was 30.592 μg·cm-3. Ethanol extract of buckwheat groats was characterized by a high DPPH radical scavenging capacity (80.8%) and exhibited high capacity to inhibit self-oxidation of linolic acid W0 = 0.86. Conclusions. Investigations showed that buckwheat groats, widely used in Polish diet, due to their content of biologically active substances, may be a raw material for the production of functional food.
Evaluation of Flavonoid Contents and Antioxidant Capacity of the Aerial Parts of Common and Tartary Buckwheat Plants  [PDF]
Danuta Zielińska,Marcin Turemko,Jacek Kwiatkowski,Henryk Zieliński
Molecules , 2012, DOI: 10.3390/molecules17089668
Abstract: The analysis of major and minor flavonoids, and antioxidant capacity of stems, leaves, flowers, unripe seeds and ripe seeds of common and tartary buckwheat plants collected during different growth periods was addressed in this study. The highest rutin contents were observed in flowers and leaves collected from common and tartary buckwheat at early flowering as well as flowering and seed formation states. A low quercetin contents were found in all studied aerial part of buckwheat plants. Quercitrin (quercetin-3-rhamnoside) was only found in flowers collected at different growth periods while flavone C-glucosides were accumulated preferentially only in unripe seeds collected from common buckwheat at an early flowering state. The rank of antioxidant capacity provided for aerial parts of common and tartary buckwheat at early flowering state was as follows: flowers > leaves > stems. The highest contribution of rutin to the antioxidant capacity of the aerial parts of common and tartary buckwheat was found for stems followed by leaves, flowers and unripe seeds. The results demonstrate that flowers from common and tartary buckwheat collected at early flowering as well as flowering and seed formation states have the future potential to be a useful food ingredient.
Anti-Fatigue Properties of Tartary Buckwheat Extracts in Mice  [PDF]
Hong-Mei Jin,Ping Wei
International Journal of Molecular Sciences , 2011, DOI: 10.3390/ijms12084770
Abstract: Anti-fatigue properties of tartary buckwheat extracts (TBE) was investigated in male Kunming mice. The animals were divided into four groups. The first group, designated as the control group (control), was administered with distilled water by gavage every day for 28 days. The other three groups, designated as TBE treatment groups, were administered with TBE of 60, 120 and 240 mg/kg body weight, respectively, by gavage every day for 28 days. Exhaustive swimming time, blood lactic acid (BLA), blood urea nitrogen (BUN), tissue glycogen, glutathione peroxidase (GPx) and superoxide dismutase (SOD) of mice after swimming were determined. The results showed that tartary buckwheat extracts had anti-fatigue properties, which extended the exhaustive swimming time of mice, effectively inhibiting the increase of BLA, decreasing the level of BUN, increasing the tissue glycogen content and the activities of SOD and GPx of mice. However, further study is needed to elucidate the exact mechanism of the effect of TBE on fatigue.
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