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In this study, the effect of anthocyanin-rich popping maize flour on phenolic profile, antioxidant capacity and color of bread were investigated. Texture and sensory properties of maize mix-breads were evaluated also. Replacing 30% of wheat flour with blue- and dark-red-seeded maize flours increased the content of total phenolic compounds, ferulic and p-coumaric acids of mix-breads compared to the control bread. In addition, anthocyanins from maize flours improved functional profile of breads. Despite thermal degradation, the content of anthocyanins in crumb of blue and dark-red maize mix-breads was high and amounted to 142.3 mg CGE/kg and 84.4 mg CGE/kg, respectively. In his acylated and non-acylated forms, cyanidin 3-glucoside was the most prevalent anthocyanins in maize mix-breads. However, given to the synergistic and antagonistic interaction that arises from the coexistence of numerous antioxidant compounds in food, anthocyanin-rich maize flour had no effect on the increase in the bread antioxidant capacity. Anthocyanin-rich maize flour changed the bread crumb color to a red range. Although maize mix-breads had worse textural properties compared to the wheat bread, their sensory quality was improved.
Disturbance of the antioxidative-oxidative balance is a predisposing factor in the development of a variety of diseases. Microelements, including zinc and copper, are components of active enzyme regions participating in anti-oxidative systems. Patients with malabsorption syndrome may suffer from diseases related to the chronic deficiency of micro- and macroelements and vitamins, but also experience health problems due to an impaired antioxidative plasma defence, i.e. illnesses caused by oxidative stress. The aim of the study was to assess zinc and copper concentrations as well as the total antioxidant capacity of blood plasma in 33 patients hospitalized in the Department of Internal Medicine, Metabolic Diseases and Dietetics, presenting symptoms of intestinal malabsorption such as weight loss, abdominal pain and diarrhoea. Blood donors made up the control group. Statistically significantly lower concentrations of zinc and copper were found in the study group as compared to the control group for women and men together as well as for women and for men separately (p < 0.05). A significantly lower FRAP (Ferric Reducing Ability of Plasma) value as a measure of blood plasma the total antioxidative capacity was found in the study group of men in comparison with men from the control group (p < 0.05). Patients showed deficiencies of the two microelements despite normal values of BMI (Body Mass Index) and laboratory parameters such as haemoglobin, protein, albumin and iron concentrations. Regardless of the nutritional state assessment, patients with malabsorption syndrome should receive adequate supplementation of vitamins and microelements.
Roasted sesame seeds, pumpkin seeds, sunflower seeds, soy beans, and wheat germs were obtained from Ekoprodukt company (Częstochowa, Poland). Phenolic compounds were extracted with 80% aqueous methanol. The extract of roasted sunflower seeds was characterised by a higher content of total phenolics (158 mg/g). The Total Antioxidant Capacity was the highest in the extract of roasted sunflower seeds (0.478 mmol Trolox/g) followed by the extract of roasted wheat germs (0.066 mmol Trolox/g). The extracts of roasted sunflower seeds and wheat germs were strong scavengers of DPPH radical. Their reducing power was strong as well.
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Antioxidant capacity of thermally-treated buckwheat

63%
This paper reports the use of an in vitro chemiluminescent method, ORACFL and SOD-like activity assays for the evaluation of antioxidant capacity of the whole buckwheat and its products after hydrothermal treatment. Phosphate buffer (0.75 mmol/L, pH 7.4) and 80% methanol (v/v) were used for the preparation of extracts originated from untreated buckwheat, hydrothermally-processed whole buckwheat, and obtained light groat and hull from the treated whole buckwheat. The antioxidative capacities of water- (ACW) and lipid-soluble (ACL) compounds were investigated by a facile chemiluminescence assay using a Photochem® device. The superoxide dismutase-like activity (SOD-like activity) was evaluated as free radical scavenging activities of the extracts against superoxide anion radicals (O2 -􀀀) whereas Oxygen Radical Antioxidant Capacity (ORACFL) of the extracts was determined with the spectrofluorimetric assay. Moreover, the content of flavonoids in untreated buckwheat and its products after hydrothermal treatment was provided. The antioxidant capacity of the whole buckwheat before hydrothermal treatment evaluated with the chemiluminescence assay was formed mainly by lipid soluble antioxidants (ACL; 88.8 μmol Trolox/g d.m.) and only in part by the water soluble compounds (ACW; 5.1 μmol Trolox/g d.m.). The hydrothermal treatment of buckwheat whole grains caused a decrease in ACW and ACL by approximately 58% and 17%, respectively. The changes in the antioxidant capacity of untreated buckwheat and its products obtained after hydrothermal treatment were confirmed by the application of SOD and ORACFL methods. Antioxidant capacity of buckwheat material was related to changes in flavonoids composition provided by HPLC analysis.
Tea and herbal infusions are among the major contributors of phenolic compounds, specifically flavonoids, in our daily diet. Honey is another antioxidant-rich food that is widely used as a natural sweetener. In this work, the effects of honey addition on antioxidant properties of different herbal teas were investigated. For this purpose, 2 different types of honey (flower and pine honey) were added into 9 different herbal teas (melissa, green tea, rosehip, sage, echinacea, fennel, linden, daisy, and ginger) at 4 different temperatures (55°C, 65°C, 75°C, and 85°C), and the changes in the content of total pheolics, total flavonoids, and total antioxidant capacity were determined. The total phenolic content and the total antioxidant capacity of the honey-added-tea samples were found to be increased (up to 57% for both), especially with pine honey and at higher temperatures of honey addition. The findings of this study supported the use of honey as a natural sweetener in tea in order to be able to benefit from the health-enhancing antioxidative properties of these two promising food products.
Abiotic stress factors are among the major causes of lower crop yields. It is known, that in response to cold and/or osmotic stress, crops activate various defense mechanisms, including morphological, physiological and metabolic adaptations. Secondary metabolism, especially phenolic compounds, seem to be an important factor of stress-induced metabolic re-engineering as their levels are alternated by abiotic stress in plants. Despite the fact, that the nature and function of phenolic compounds was already studied in various plant species, it is important to define tissue-specific changes induced by two most potent abiotic stressors – low temperature and decreased water potential. Moreover, in fields, the appearance of single stress is rather rare. Usually two or more factors are acting in parallel, which may potentially result in different effects. Therefore, the aim of this study was to analyze selected elements of secondary metabolism in roots of germinating soybean seeds under cold stress, osmotic stress and both stresses combined. In addition the effects of constant and persistent stress were compared to those induced by sudden and brief stress appearance, as well as after the post-stress recovery process. In the presented study standard methods for identification and quantification of phenolic acids and isoflavones were used and the antioxidant capacity of the radicle extracts was measured. The phenolic metabolism in plants was greatly intensified in response to cold and osmotic stress and remained at high level during the post-stress recovery. The amount and composition of both phenolic acids and identified isoflavones also changed in stress- and duration-dependent manner. This proves an important role of phenolic compounds in abiotic stress response of germinating soybean seeds and opens up new perspectives for further investigations.
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