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Search Results: 1 - 10 of 13570 matches for " ascorbic acid. "
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Synergism Effect between Phenolic Metabolites and Endogenous Antioxidants in Terms of Antioxidant Activity  [PDF]
María Noguer, Ana B. Cerezo, M. Luisa Moyá, Ana M. Troncoso, M. Carmen García-Parrilla
Advances in Chemical Engineering and Science (ACES) , 2014, DOI: 10.4236/aces.2014.42029

Polyphenolic compounds, widely distributed in plant kingdom, have been exhaustively studied for their bioactive properties specially antioxidant activity. However, they are extensively metabolized by human organism and the resulting metabolites are largely responsible for their effects. Furthermore, they may interact with the endogenous antioxidant network being this possibility scarcely studied. Plasma antioxidant network encompasses antioxidant enzymes and other substances such as uric acid. In addition, ascorbic acid is the major compound representing water soluble compartment both in foods and human body. The interaction of this vitamin with phenolic compound is largely unexplored. This work aims to study if there is a synergic effect between phenolic metabolites and main antioxidants (uric and ascorbic acid). For this purpose, the antioxidant activity was evaluated in terms of ORAC (oxygen radical absorbance capacity) and FRAP (ferricreducing antioxidant power) as these tests involved either HAT (Hydrogen Atom Transfer) or SET (Single Electron Transfer) mechanisms. Additionally, a kinetic studied was developed to test if the rate constant presented a synergic effect. Protocatechuic acid, 3,4-dihydroxyphenylacetic acid, 3,4-dihydroxyphenylpropionic acid and 3-hydroxyphenylacetic acid were selected as they were metabolites of polyphenol compounds such as anthocyanins, quercetin, neohesperidin, chlorogenic acid and hesperetin present in wines, orange and strawberries. A synergic effect was proved for the combination of ascorbic acid with 3,4-dihydroxyphenylacetic acid, both in terms of antioxidant activity and potent increase of velocity of the antioxidant reaction that took place.

Preliminary Study on Bioactive Compounds of Citrus × myrtifolia Rafinesque (Chinotto) to Its Potential Application in Food Industry  [PDF]
Monica Scordino, Leonardo Sabatino, Adalgisa Belligno, Giacomo Gagliano
Food and Nutrition Sciences (FNS) , 2011, DOI: 10.4236/fns.2011.27094
Abstract: The present study investigated for the first time some physical quality attributes of unripe Citrus x myrtifolia Rafinesque which is the ingredient of the popular soft drink Chinotto. Samples for analysis were processed to better reproduce the crude materials used for industrial chinotto extract, discarding part of the juice. Fruit bioactive compounds such as ascorbic acid, carotenoids, chlorophylls, flavonoids and antioxidant capacity were estimated. An important nutritional aspect arose from the data presented was the high concentration of flavonoids (780 mg/100 g FW) and vitamin C (42 mg/100 g FW). A good antioxidant capacity (5872 µM Trolox equivalents/100 g FW) was estimated by oxygen radical absorbing capacity (ORAC). This matrix could be considered as a good nutraceutical source, giving new opportunity to citrus industry.
Comparative Study of Ascorbic Acid and Tocopherol Concentrations in Hydroponic- and Soil-Grown Lettuces  [PDF]
Drew N. Buchanan, Stanley T. Omaye
Food and Nutrition Sciences (FNS) , 2013, DOI: 10.4236/fns.2013.410136
Abstract: Hydroponically-grown produce may be a way of helping to feed the world a variety of fruits and vegetables, regardless of soil quality, space availability or climate. The objective of this study was to determine whether hydroponicallygrown lettuce contains as much ascorbic acid and tocopherol as soil-grown lettuce. We analyzed four varieties of lettuce, including: Waldmann’s Dark Green, Red Lollo Antago, Red Romaine Annapolis, and Butterleaf. The tocopherol content of hydroponically-grown Waldmann’s Dark Green, Red Lollo Antago, and Red Romaine Annapolis was 229%, 497% and 492% higher, respectively, compared to their soil-grown counterpart. The ascorbic acid content of hydroponically-grown Waldmann’s Dark Green, Red Lollo Antago, and Red Romaine Annapolis was 93%, 171% and 216% higher, respectively, compared to their soil-grown counterparts. Hydroponically grown lettuce varieties are significantly higher in both ascorbic acid and tocopherol content than their soil-grown counterparts, and hydroponic gardening is a viable option for producing nutritious fruits and vegetables.
Prevalence of Iron Deficiency and Iron Deficiency Anemia in Infants and Children and Treatment with Microencapsulated Iron II Fumarate and Supplied Ascorbic Acid as “Sprinkles”  [PDF]
Abdullah Al-Mamari, Mohammad A. Al-Hegami, Sadeq Al-Hag, Mahmoud Al-Buryhi, Safa Al-Amawi, Leena Ahmed, Lila Al-Awadi, Sarah Al-Jamal, Wafa Mohammad, Yasmin Mohammad
Pharmacology & Pharmacy (PP) , 2014, DOI: 10.4236/pp.2014.57081

Background: Iron deficiency anemia (IDA) in children and infants is a common nutritional problem all over the world. Infants and young children have a high risk for developing iron deficiency (ID) because they have high demand for iron during the period of rapid growth. This is aggravated by the insufficiency of iron in their diet. Iron supplementation programs using pediatric tablets or drops have not been successful in the control of anemia amongst infants and children in some countries. “Sprinkles” is an innovative multi-micronutrient home fortification strategy to control iron deficiency and anemia to be more useful. Objective: The objective was to estimate the prevalence ID and IDA in infants and children in Ibb City, Yemen Republic; evaluate the use of a new form of iron and determine the hematologic response to different doses and forms of iron in Sprinkles and iron drops. Design: Using a prospective, randomized, controlled design, we studied 337 randomly children aged 24 - 48 months and infants aged 6 - 24 months in Ibb City (hemoglobin: 70 - 99 g/L). One group received a daily sachet of microencapsulated ferrous fumarate (80 mg elemental Fe) in powder form plus ascorbic acid to be sprinkled onto any complementary food eaten (sprinkles group); a control group received ferrous sulfate drops 3 times/d for 2 months (total dose: 40 mg elemental Fe). Hemoglobin and serum ferritin concentrations were measured at baseline and at the end of treatment. Results: Successful treatment of anemia (hemoglobin > 100 g/L) occurred in 58% of the sprinkles group and in 56% of the drops group, with minimal side effects in both groups. Geometric mean ferritin concentrations increased significantly in each group from baseline to the end of treatment (P < 0.001). Conclusion: Use of ferrous sulfate drops or a single daily dose of microencapsulated

Ascorbic Acid Attenuates Acute Ethanol-Induced Liver Injury in SMP30 Knockout Mice  [PDF]
Eun-Mi Cho, H. M. Arif Ullah, Ahmed K. Elfadl, Myung-Jin Chung, Soong-Koo Kim, Yong Deuk Kim, Eun-Joo Lee, Kyu-Shik Jeong
Food and Nutrition Sciences (FNS) , 2017, DOI: 10.4236/fns.2017.812083
Ascorbic acid (AA) is recognized as a free radical scavenger that protects cells from oxidative stress-induced damage. However, no studies have investigated the role of AA in acute alcoholic liver disease using senescence marker protein-30 (SMP30) knockout (KO) mice. SMP30 is a novel 34-kDa protein involved in AA biosynthesis. The present study aimed to elucidate the physiological functions of AA in acute ethanol-induced liver injury using SMP30 KO mice, which cannot synthesize AA in vivo. After a 4-week experimental period, mice were divided into six groups. The following three groups comprised the ethanol treatment groups: WT-E group (wild-type), KV-E group (AA-supplemented), and KT-E group (AA-deficient). Mice were exposed to an acute dose of ethanol (6 g ethanol/kg) administered by gavage once a day for three days. The other three control groups, namely, WT-C, KV-C, and KT-C control groups, received an equal volume of water via oral administration. Analysis of changes in body weight showed that mice in the KT-E group had significant loss of body weight compared to the control, KV-E, and WT-E groups. Behavioral analysis revealed that alcohol exposure significantly increased alcohol sensitivity in the KT-E group, whereas the WT-E, KV-E, and control groups developed ethanol tolerance. Aspartate transaminase (AST) levels in the KT-E group were significantly higher than those in the control, KV-E, and WT-E groups. The number of large and binucleated hepatocytes was significantly higher in the KT-E group than in the KV-E and WT-E groups. In addition, cytochrome P450 2E1 (CYP2E1) was over expressed in the central vein in the KT-E group when compared to the KV-E and WT-E groups. Our current findings indicate that AA supplementation in SMP30 KO mice can alleviate alcohol-induced liver damage by down regulating CYP2E1 expression. These results suggest that reduced CYP2E1 expression is a novel mechanism responsible for AA-induced reduction of ethanol-mediated oxidative stress.
Electrochemical Synthesis of Three-Dimensional Polyaniline Network on 3-Aminobenzenesulfonic Acid Functionalized Glassy Carbon Electrode and Its Application  [PDF]
Lei Zhang, Qiuhua Lang, Zhige Shi
American Journal of Analytical Chemistry (AJAC) , 2010, DOI: 10.4236/ajac.2010.13014
Abstract: The electrochemical synthesis of three-dimensional (3D) polyaniline (PAN) network structure on 3-aminobenzenesulfonic acid (ABSA) functionalized glassy carbon electrode (GCE) and its electro-catalytic oxidation towards ascorbic acid (AA) had been studied. ABSA was first covalently grafted on GCE surface via the direct electrochemical oxidation of ABSA on GCE, which was followed by the electrochemical polymerization of aniline on the ABSA functionalized GCE. Then PAN-ABSA composite film modified GCE (PAN-ABSA/GCE) was obtained. Scanning electron microscope (SEM), X-ray photoelectron spectroscopy (XPS), electrochemical impedance spectroscopy (EIS) and electrochemical techniques had been employed to characterize the obtained electrodes. Due to the effective doping of ABSA in PAN, the redox electro-activity of PAN had been extended to neutral and even the basic media, thus, the PAN-ABSA composite film modified GCE could be used for electro-catalytic oxidation of AA in 0.1 M phosphate buffer solution (PBS, pH 6.8). At PAN-ABSA/GCE the oxidation over-potential of AA shifted from 0.39 V at GCE to 0.17 V with a greatly enhanced current response. The electro-catalytic oxidation peak current of AA increased linearly with the increasing AA concentration over the range of 5.00 × 10-4-1.65 × 10-2 M with a correlation coefficient of 0.9973. The detection limit (S/N = 3) for AA was 1.16 × 10-6 M. Chronoamperometry had also been employed to investigate the electro-catalytic oxidation of AA at PAN-ABSA/GCE. The modified electrode had been used for detecting AA in real samples with satisfactory results.
Selective Detection of Dopamine in the Presence of Ascorbic Acid at Poly (m-Aminobenzene Sulfonic Acid)  [PDF]
Gamze Erdo?du, Mehmet Mutluhan Mutlu
American Journal of Analytical Chemistry (AJAC) , 2011, DOI: 10.4236/ajac.2011.25066
Abstract: Poly (m-aminobenzene sulfonic acid, m-ABSA) films were electrochemically prepared by cyclic voltammetry (CV) in 0.1 mol L–1 KCl solution. The dopamine (DA) selectivity of polymeric electrodes prepared at the different thicknesses was examined in the presence of ascorbic acid (AA). The results showed that the modified electrode showed an excellent electrocatalytical effect towards oxidation of dopamine (DA) and ascorbic acid (AA). Electrostatic interaction between the negatively charged poly(m-ABSA) film and either cationic DA species or anionic AA species favorably contributed to the redox response of DA and AA. Moreover, the regular and repetitive responses for dopamine were obtained even in the presence of the some interfering substances such as ascorbic acid, NaCl, NaClO4, Na2SO4 ,NaNO3 and KCl.
Estudo da estabilidade físico-química de suco de abacaxi 'pérola'
Borges, Paulo Rogério Siriano;Carvalho, Elisangela Elena Nunes;Boas, Eduardo Valério de Barros Vilas;Lima, Juliana Pinto de;Rodrigues, Lucas Ferreira;
Ciência e Agrotecnologia , 2011, DOI: 10.1590/S1413-70542011000400013
Abstract: in this work, psycho-chemical changes caused by the storage of homemade 'pérola' pineapple juice, over 48 hours after its preparation were evaluated. four storage conditions were evaluated in a refrigerated environment (4 ±1o c) and in room temperature (22 ±1o c) both in the presence and abscence of light. the experiment was conducted with a totally random design, with treatments arranged in a factorial 2 x 2 x 6, with 2 light conditions (presence and absence), 2 temperature conditions (cooling and room temperature) and 6 sampling times (0, 6, 12, 24, 36 and 48 hours) with three replicates. ph, titratable acidity, soluble solids, total vitamin c and color using the variables: luminosity (l*), hue angle (ho) and chromaticity (c*) were analyzed. the period of storage presented a negative influence on the pineapple juice, causing a reduction of ascorbic and citric acid contents and color changes, mainly darkening. however, when stored in refrigerated environment in the abscence of light, the juice conserved its initial features for a longer time, which were better preserved by low temperatures.
Uso de scanner em espectrofotometria de absor??o molecular: aplica??o em experimento didático enfocando a determina??o de ácido ascórbico
Gomes, Marcos S.;Trevizan, Lilian C.;Nóbrega, Joaquim A.;Kamogawa, Marcos Y.;
Química Nova , 2008, DOI: 10.1590/S0100-40422008000600050
Abstract: quantitative analysis of colored substances is generally performed using a spectrophotometer for detection of radiation. however, the combination of digital images and mathematical conversion of colors is an alternative for quantitative procedures based on colored chemical reactions. this work proposes a didactic experiment using a scanner for determination of ascorbic acid in medicines based on the formation of the prussian blue complex. results were in good agreement with a conventional spectrophotometer method and the procedure is attractive for instrumental analysis undergraduate courses.
Avalia??o do teor e da estabilidade de vitaminas do complexo B e vitamina C em bebidas isot?nicas e energéticas
Castro, Fernanda J. de;Scherer, Rodrigo;Godoy, Helena T.;
Química Nova , 2006, DOI: 10.1590/S0100-40422006000400017
Abstract: vitamin c stability and concentration was evaluated in isotonic beverages and b group vitamins (b1, b2, b3, b5 and b6) in power beverages. the amount of vitamins was found to be above of that declared on the labels, even after the shelf life had been exceeded. a small decrease in the amount of b group vitamins was observed during the shelf life of the products. in the case of vitamin c this decrease was slightly higher. the present research shows the need of increased quality control and inspection.
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