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Search Results: 1 - 10 of 3905 matches for " antioxidant "
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Antioxidant Contents (Vitamin C) of Raw and Blanched Different Fresh Vegetable Samples  [PDF]
Oluwafunmilayo O. Olayinka, Ajibola M. Kareem, Isaac B. Ariyo, Stephen K. Omotugba, Adedayo O. Oyebanji
Food and Nutrition Sciences (FNS) , 2012, DOI: 10.4236/fns.2012.31004
Abstract: The study was aimed to determine the antioxidant contents and the effect of different blanching times (5 min, 10 min, 15 min and 20 min) on antioxidant contents of three different selected fresh vegetables. Three different types of vegeta- ble were used namely Amaranthus specie locally known as spinach, namely “tete”, (Celosia argentea), soko, (Solonum nodifiorum) and odu, (Telfeira occidentalis) were analyzed for their antioxidant contents. The analysis revealed that raw vegetables have the highest amount of antioxidant contents. Telferia occidentalis had the highest antioxidant content followed by Solonum nodifiorum. It was observed that blanching time had an adverse effect on the antioxidant contents of the blanched vegetables. The antioxidant contents of tete, soko and odu were significantly decreased (p < 0.05) after blanching.
Influence of Various Antioxidants on the Characteristics of Plain Yogurt  [PDF]
Blake Brignac, Kayanush J. Aryana
Food and Nutrition Sciences (FNS) , 2012, DOI: 10.4236/fns.2012.39168
Abstract: Free radical damage has been implicated in ageing and in certain degenerative conditions such as Alzheimer’s disease and other forms of dementia. Ageing is also associated with a progressive decline in the function of the immune system and an increased susceptibility to infection. Antioxidants protect the body from free radical damage. Vitamin E is the major antioxidant vitamin in body tissues and is considered the first line of defense against cell membrane damage. Other antioxidant defenses that protect the body from free radical damage include vitamin C and beta carotene. Yogurt is considered a healthy food product and its sales have been steadily increasing over the past 5 years. The objective was to study the influence of various antioxidants on the quality characteristics of yogurt. The antioxidants Vitamin C, vitamin E and beta carotene individually and in combination were incorporated at 100% of their respective recommended dietary allowance of 60 mg, 12 mg and 3 mg in 240 mL of yogurt. Yogurt manufacture and all experiments were conducted in triplicate. Use of antioxidants in yogurt manufacture significantly influenced yogurt viscosity, flavor, appearance, body texture but did not influence syneresis, lactic acid bacterial counts and pH.Depending upon the application antioxidants can be recommended in yogurt manufacture.
Hepatoprotective Effect of Vitamin C (Ascorbic Acid)  [PDF]
Elias Adikwu, Oputiri Deo
Pharmacology & Pharmacy (PP) , 2013, DOI: 10.4236/pp.2013.41012
Abstract: Human and animal studies have shown that some drugs and chemical agents have potential hepatotoxic effects. The hepatotoxic effect of drugs and some chemical agents is reported to be associated with the generation of reactive oxygen species (ROS). These ROS are reported to be associated with lipid peroxidation in the liver. This mechanism has led to continuous evaluation of the hepatoprotective effect of antioxidants in humans and animals. Among the antioxidants been evaluated is vitamin C which is a water soluble antioxidant. Reports have linked vitamin C with hepatoprotective property in animals and humans. It synergistic hepatoprotective effect with other antioxidants was also reported. Due to these reports a comprehensive literature review on the hepatoprotective property of vitamin C in humans and animals was performed. It was observed that vitamin C exhibited a reputable hepatoprotective effect in humans and animals. Research showed that vitamin C inhibited hepatotoxicity induced by drugs, heavy metals, organophosphate insecticides and some chemical agents. Vitamin C was reported to normalized levels of serum alanine aminotransferase, aspartate aminotransferase, gamma glutamine, alkaline phosphatase, lactate dehydrogenase and malondialdehyde and serum bilirubin in intoxicated animals. It potentiates the activities of free radical scavengers, superoxide dimutase, and catalase glutathione peroxidase thereby preventing microsomal lipid peroxidation, liver fibrosis, liver necrosis and hepatic inflammation. In humans vitamin C was reported to be beneficial in non alcoholic steatohepatitis and in patients with fatty liver disease. Hepatoprotective property of vitamin C is attributed to it antioxidant property. Vitamin C (ascorbic acid) which is a major water-soluble antioxidant is believed to decrease lipid peroxidation either directly or indirectly by regenerating vitamin E. Vitamin C is an important free radical scavenger in extracellular fluids, trapping radicals and protecting biomembranes from peroxide damage. Vitamin C effectively scavenges singlet oxygen, superoxide, hydroxyl, water soluble peroxyl radical and hypochlorous acid. It is also reported to be an excellent source of electrons and therefore can donate electrons to free radicals such as hydroxyl and super oxide radicals and quench their activity. Vitamin C is an essential co-factor involved in many biochemical functions and acts as an electron donor or reducing agent. In this review it is observe that vitamin C has hepatoprotective effect which increases
Studies of the Relationship between Structure and Antioxidant Activity in Interesting Systems, Including Tyrosol, Hydroxytyrosol Derivatives Indicated by Quantum Chemical Calculations  [PDF]
Rogaie Rezaei-Sadabady, Nosratollah Zarghami, Abolfazl Barzegar, Akram Eidi, Abolfazl Akbarzadeh, Mustafa Rezaei-Tavirani
Soft (Soft) , 2013, DOI: 10.4236/soft.2013.23004
Abstract:

In nature, tyrosol (TY) and hydroxytyrosol (HT) are found in olive leaves which are for medical aims, with immune stimulant and antibiotic properties as well as the ability to be used for the treatment of neurodegenerative diseases such as Alzheimer. This ability of phytochemical TY and HT compounds are mainly believed to be of higher radical scavenging potential with effective antioxidant properties. In order to establish the possible structure-antioxidant activity relationship of tyrosol, hydroxytyrosol, hydroxytyrosol acetate and two designed hydroxytyrosol derivatives were studied by the help of quantum chemical calculations. The molecular electronic properties such as heat formation of the neutral, radical and orbitals energies were calculated as descriptors to predict the H atom donating abilities of compounds. Considering the results from the calculated descriptors, the derivatives having OH group substitutions in position number four of the aromatic ring can be classified highly active and better antioxidant compound. Therefore, the designed hydroxytyrosol derivatives showed most active feasible H atom donation. This work can be useful to design novel antioxidants.

Natural Antioxidants: Function and Sources  [PDF]
Yevgenia Shebis, David Iluz, Yael Kinel-Tahan, Zvy Dubinsky, Yaron Yehoshua
Food and Nutrition Sciences (FNS) , 2013, DOI: 10.4236/fns.2013.46083
Abstract: The definition of antioxidants, given in 1995 by Halliwell and Gutteridge, stated that an antioxidant is “any substance that, when present at low concentrations compared with that of an oxidizable substrate, significantly delays or inhibits oxidation of that substrate” [1]. In 2007, Halliwell gave a more specific definition, stating that an antioxidant is “any substance that delays, prevents or removes oxidative damage to a target molecule” [2]. Oxidation reactions produce free radicals that can start multiple chain reactions that eventually cause damage or death to the cell. Antioxidants remove these free-radical intermediates by being oxidized themselves, and inhibit other oxidation reactions, thus stopping the harmful chain reactions. Such oxidative processes are dangerous for all living cells, especially those in proximity to sites where active oxygen is released by photosynthesis. Spontaneous oxidation causes food rancidity and spoilage of medicines. Furthermore, oxidative stress is an important part of many human diseases that can occur, inter alia, due to a lack of appropriate nutrition and exercise, air pollution, smoking, and more, leading to lethal diseases, such as cancer. Therefore, it is imperative to include antioxidants in our diets. Due to the fact that synthetically produced antioxidants are currently used in the food and pharmaceutical industries in order to prolong product shelf life, there is currently a strong trend to search for large, available, and efficient natural sources of antioxidants to replace the synthetic ones, thus minimizing damage to our cells.
Anti-Oxidative Biomarkers in Newborn Kids of Aardi Goats  [PDF]
M. J. Al-Hassan, H. E. Mohamed, K. A. Al-Samawi, M. A. Al-Badwi
Agricultural Sciences (AS) , 2017, DOI: 10.4236/as.2017.810085
Abstract:
The provision of basic data about oxidative stresses on Aardi goats will be beneficial for understanding the basic physiological indices of a valuable local breed of goats under harsh desert condition. The primary aim of this study is to assess the antioxidant status of newly born Aardi kids. Eighteen newly born Aardi kids were used in this study; sampled weekly as from week 1 to 4 for the assay of the plasma Total Antioxidant Capacity (TAC), ThioBarbituric Reactive Substances (TBARS), and Superoxide Dismutase (SOD) activities. For new-born, total blood antioxidants concentrations did not change during the four weeks of life. However, TBARS increased during the 2nd and 3rd week of age (p < 0.05). The results indicated that TAC in kids from birth to 4 weeks of age tended to increase, but not significantly. Serum TBARS concentrations increased on the 2nd week and decreased significantly on the 4th week of age. Serum SOD levels did not change significantly, even though, the trend showed a decline during 1st to 3rd week of age. The small decrease in serum TBARS in the serum of kids can be considered as an indication of decreased oxidants, which in turn, resulted in a reduction in serum SOD concentration. In conclusion, this basic data could help in understanding the adaptational physiology of young local Saudi goats.
Estudio de los componentes antioxidantes y actividad antioxidante en tomates
Zapata,Luz M.; Gerard,Liliana; Davies,Cristina; Schvab,María del C.;
Ciencia, docencia y tecnolog?-a , 2007,
Abstract: concentration of antioxidant compounds and total antioxidant activity in tomatoes were investigated during growth, storage, ripening and marketing. lycopene, bcarotene, l-ascorbic acid and total phenolics were the analysed antioxidant compounds. antioxidant activity was determined using the "ferric reducing/ antioxidant power" (frap) method and the ?-carotene decoloration reaction. ascorbic acid, lycopene and ?-carotene concentration was 2,6 times higher than the initial level during marketing, while the antioxidant activity in the last stage was 2,1 and 3,5 times higher than the levels corresponding to growth in both methods respectively. as a result, the consumers have a fruit with a high amount of antioxidants compounds, with the consequent ability to capture free radicals present in the human body. for the same reason, high antioxidants compounds concentrations in tomatoes may reduce the risks of contracting several chronic diseases.
Polyphenol Content and Antioxidant Effects in Herb Teas  [PDF]
Shizuo Toda
Chinese Medicine (CM) , 2011, DOI: 10.4236/cm.2011.21005
Abstract: Herb teas, Arabian jasmine, Balsam pear, Barley grass, Guava, Hardy rubber tree, Japanese persimmon, Jobs tears, Oolong tea, Puerh tea and Wolofberry have been consumed as beverages for health in Asia. Oxidative stress induces various diseases. Some of them, Arabian jasmine, Guava, Hardy rubber tree, Japanese per-simmon, Oolong tea and Puerh tea, have high total polyphenol content and antioxidant activities. Herbs and herbal polyphenols pay in controlling oxidation and prevent the damage by oxidation. These results showed that some of them, Arabian jasmine, Guava, Hardy rubber tree, Japanese persimmon, Oolong tea and Puerh tea, have high total polyphenol content and antioxidant activities. It has been demonstrated that high total polyphenol content in the herb teas provides high antioxidant activities.
Caffeoyl Derivatives: Major Antioxidant Compounds of Some Wild Herbs of the Asteraceae Family  [PDF]
Didier Fraisse, Catherine Felgines, Odile Texier, Jean-Louis Lamaison
Food and Nutrition Sciences (FNS) , 2011, DOI: 10.4236/fns.2011.230025
Abstract: The polyphenolic composition and antioxidant activity of the aerial parts of 18 medicinal or food plants of the As- teraceae family were studied. Five main caffeoyl derivatives were determined individually by HPLC and compared with levels determined by colorimetry for total dihydroxycinnamic derivatives and total phenolics. The aim of this study was to assess the contribution of these constituents to the antioxidant activity of the herbs determined by DPPH radical scavenging tests. Significant correlations were found between total phenolic (R2 = 0.8904), total dihydroxycinnamic derivative (R2 = 0.8529) and total caffeoyl derivative (R2 = 0.7172) concentrations and the DPPH-scavenging ability of all herbs. The antioxidant activity of the main constituents, including chicoric acid (EC50 = 8.24 µmol/l) or 3,5- dicaffeoylquinic acid (EC50 = 7.62 µmol/l), was very high compared to vitamin C (EC50 = 15.66 µmol/l). Thus, for each species, antioxidant activity mainly involves the major caffeoyl derivatives. The contribution to antioxidant activity were assessed as 48.92% for 3,5-dicaffeoylquinic acid in Tanacetum parthenium (30.08 g/kg), and 68.96% for chicoric acid in Taraxacum officinale (34.08 g/kg). The main caffeoyl derivatives among polyphenols can be considered as the major antioxidant compounds of the studied Asteraceae herbs.
Cortisol levels and serum antioxidant status following chemotherapy  [PDF]
Eugenia Limberaki, Phaedra Eleftheriou, Georgios Gasparis, Eugenios Karalekos, Vassilis Kostoglou, Christos Petrou
Health (Health) , 2011, DOI: 10.4236/health.2011.38085
Abstract: Chemotherapy results in increased free radical formation and depletion of tissue antioxidants. Moreover, patients receiving chemotherapy are under emotional stress, which is also accompanied by low antioxidant levels. In the present study, we measured cortisol, the main stress hormone, and total antioxidant capacity (TAC) in serum of 51 cancer patients during chemotherapy. Antioxidant activity was estimated by measuring the influence of serum in oxidation of ABTS (2,2'-azino-bis (3-ethylbenz-thiazoline-6-sulfonic acid to ABTS+ by methmyoglobin (Antioxidant kit of Cayman). Serum cortisol was measured using an ELISA colorimetric assay. Serum TAC was significantly decreased (75% decrease compared to normal levels, p = 0.001) in all patients during chemotherapy, while blood cortisol concentration was increased by 10%, (p = 0.044). Lower antioxidant levels and higher cortisol concentration were detected in patients receiving chemotherapeutic drugs daily, compared to the ones receiving chemotherapy once a week. A difference between sexes was observed with male patients presenting lower antioxidant status and higher cortisol levels than females. A significant and persistent decrease in antioxidant capacity accompanied by increased cortisol concentration was observed in all patients during chemotherapy. This fact, which is probably generated by biological and emotional stress, increases the probability of harmful side effects and organism weakening and needs to be considered during patients’ treatment.
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