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Antioxidant Activity (antioxidant + activity)
Kinds of Antioxidant Activity Selected AbstractsANTIOXIDANT ACTIVITY AND TOTAL PHENOLIC CONTENTS IN PEEL AND PULP OF CHINESE JUJUBE (ZIZIPHUS JUJUBA MILL) FRUITSJOURNAL OF FOOD BIOCHEMISTRY, Issue 5 2009ZIPING XUE ABSTRACT Total phenolic contents in peel and pulp of the fruits of three Chinese jujube cultivars (Ziziphus jujuba cv. mayazao, Z. jujuba cv. dongzao and Z. jujuba cv. yuanzao) were determined. The antioxidant activities in peel and pulp of the jujube fruits were measured by different methods, including 2,2-Diphenyl-1-picrylhydrazyl (DPPH) radical scavenging capacity, ferric reducing antioxidant power (FRAP) and Trolox equivalent antioxidant capacity (TEAC). The total phenolic content in peel was five to six times higher than that in the pulp of all the three cultivars. The phenolics contents in the jujube were different with cultivars. The EC50 (Concentration of lyophilized samples needed to decrease the initial DPPH radical concentration by 50%), FRAP and TEAC values of the peel and pulp were remarkably correlated to their total phenolic contents (R = ,0.922, R = 0.985 and R = 0.997, respectively). The results indicated that the high capacity of antioxidant of Chinese jujube fruit could be attributed to the high phenolic contents in the fruit. PRACTICAL APPLICATIONS There was an expanding quest surrounding the use of antioxidant because they have the capacity to protect from the damage because of free radicals and reactive oxygen species. However, the safety of synthetic antioxidant was challenged. Much attention has been focused on the use of natural antioxidant. Interest in food phenolics had increased greatly because of their antioxidant and possible promoting-health role in human health. In this study, total phenolic contents and antioxidant capacities in vitro of Chinese jujube (Ziziphus jujuba Mill) peel and pulp were researched. The work would help to explore a natural antioxidant for possible application in food and dietary supplemental products for health promotion. [source] ANTIOXIDANT ACTIVITY AND PHENOLIC ACID CONSTITUENTS OF CHESTNUT (CASTANIA SATIVA MILL.) HONEY AND PROPOLISJOURNAL OF FOOD BIOCHEMISTRY, Issue 4 2009ALI OSMAN SARIKAYA ABSTRACT This study describes the constituents of phenolic acids and antioxidant activities of chestnut (Castania sativa Mill.) honeys and propolis in Turkey. Antioxidant activity of the chestnut honeys and propolis were examined by three different methods, namely scavenging of free radical 2, 2-diphenyl-1-picrylhydrazyl, FRAP, and cupric reducing antioxidant power. Total phenolic contents were determined by using Folin,Ciocalteu reagent as GA equivalent. The phenolic constituents were also determined by HPLC. The antioxidant activities were compared with standard antioxidants such as catechin, BHT and Trolox. The antioxidant activities of all the samples were found high and related to the sample concentrations. The ethanolic propolis extracts showed the highest antioxidant activity. The major phenolic acids of the chestnut honeys and propolis identified by HPLC with PDA detection were coumaric acid, FA, cinnamic acid, CA and ChA. PRACTICAL APPLICATIONS In this study, some phenolic acid components and antioxidant capacity of chestnut (Castania sativa Mill.) honey and propolis were measured. The comparative findings from antioxidant activities and phenolic acid analyses of honey and propolis samples of chestnut origin provide important criteria for considering their nutritional and nutraceutical potentials. Comparison of our results with literature data also ranks the chestnut honey and propolis as better sources of antioxidants among those from other floral origins. [source] ESR SPECTROSCOPY INVESTIGATION OF ANTIOXIDANT ACTIVITY AND PROTECTIVE EFFECT ON HYDROXYL RADICAL-INDUCED DNA DAMAGE OF ENZYMATIC EXTRACTS FROM PICRORRHIZA KURROAJOURNAL OF FOOD BIOCHEMISTRY, Issue 6 2008SOUNG-HEE CHOI ABSTRACT The potential antioxidant activity of enzymatic extracts from Picrorrhiza kurroa was evaluated on 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical, hydroxyl radical and alkyl radical-scavenging activities using an electron spin resonance spectrometer (JEOL Ltd., Tokyo, Japan). P. kurroa was enzymatically hydrolyzed by seven carbohydrases and five proteases to prepare water-soluble extracts. The DPPH radical-scavenging activities of the pancreatic trypsin and Amyloglucosidase (AMG) (artificial carbohydrase by Novozyme Nordisk, Bagsvaerd, Denmark) extracts from P. kurroa were the highest among protease and carbohydrase extracts, and 50% inhibitory concentration (IC50) values were 35.58 and 29.03 µg/mL, respectively. The hydroxyl radical-scavenging activity of the Protamex and Viscozyme extracts from P. kurroa were the highest scavenging activities, and the IC50 values were 0.46 and 1.89 mg/mL, respectively. In addition, the Protamex and Maltogenase extracts from P. kurroa showed the highest alkyl radical-scavenging activities, and the IC50 values were 18.03 and 10.66 µg/mL, respectively. The protective effect of the Protamex extracts from P. kurroa on DNA damage which was free radical-induced was 92% at 3 mg/mL. These results indicate that enzymatic extracts of P. kurroa show potent antioxidant activity. PRACTICAL APPLICATIONS Picrorrhiza kurroa could be used to produce protein and carbohydrate extracts with antioxidative activity. Many industrial commercial enzymes such as Promozyme, Celluclast 1.5 L FG, Maltogenase L, Viscozyme L, Termamyl SC, Dextrozyme E, AMG 300 L, Protamex, Flavourzyme 500 MG, Neutrase 0.8 L, Pancreatic Trypsin and Alcalase 2.4 L could be also used to attain the extracts processing the high antioxidative activity. The extracts can be used as natural antioxidants. [source] DISTRIBUTION AND ANTIOXIDANT ACTIVITY OF POLYPHENOLS IN RIPE AND UNRIPE TREE PEPPER (CAPSICUM PUBESCENS)JOURNAL OF FOOD BIOCHEMISTRY, Issue 4 2007G. OBOH ABSTRACT Capsicum pubescens, commonly known as tree pepper with its distinctive thick-fleshed pungent fruit (ripe and unripe), is used as a vegetable condiment or made into a sauce. The present study sought to determine the distribution of polyphenols and antioxidant activity in its thick flesh and seeds. Free, bound and total phenol content of each extract was subsequently determined, while reducing power, Fe (II)-chelating ability, OH radical-scavenging ability and ability of the extracts to inhibit lipid peroxidation in basal and Fe (II)-induced lipid peroxidation in brain was used for antioxidant capacity. Unripe pepper had higher total phenol content than ripe pepper; however, there was no significant difference ( P > 0.05) in the total phenol content of flesh for both peppers (unripe [110 mg/100g], ripe [95 mg/100 g]) and the seed (unripe [110.0 mg/100 g ], ripe [90 mg/100 g]). Nevertheless, the free polyphenols in flesh and seed of the peppers were significantly higher ( P < 0.05) than the bound polyphenols. All the extracts inhibited lipid peroxidation in a dose-dependent manner, although free polyphenols from the flesh of ripe pepper caused the highest inhibition in malondialdehyde production in rat's brain. Free and bound polyphenols from the flesh of unripe pepper had the highest Fe (II)-chelating and OH radical-scavenging ability. While the free polyphenols from the flesh of ripe pepper had the highest reducing power, this may have accounted for its ability to reduce Fe (II)-induced lipid peroxidation. Therefore, by removing the seed from pepper, a 50% loss in the total phenol content would result, which will substantially reduce antioxidant activity. PRACTICAL APPLICATIONS Because many degenerative human diseases have been recognized as being a consequence of free radical damage, there have been many studies undertaken on how to delay or prevent the onset of these diseases. The most likely and practical way to fight against degenerative diseases is to improve body antioxidant status, which could be achieved by higher consumption of vegetables and fruits. Foods from plant origin usually contain natural antioxidants that can scavenge free radical. The inclusion of either ripe or unripe pepper in a diet is a common practice in Africa and some other parts of the world; our recent findings on the antioxidant properties of Capsicum pubescens clearly indicate that its inclusion in the diet will contribute greatly in the prevention of neuro-degenerative diseases associated with oxidative stress, by inhibiting lipid peroxidation. Moreover, removing the seeds of this pepper during food processing will reduce the total phenol content by 50%, and consequently reduce the antioxidant activity. [source] ANTIOXIDANT ACTIVITY OF FERMENTED BERRY JUICES AND THEIR EFFECTS ON NITRIC OXIDE AND TUMOR NECROSIS FACTOR-ALPHA PRODUCTION IN MACROPHAGES 264.7 GAMMA NO(,) CELL LINEJOURNAL OF FOOD BIOCHEMISTRY, Issue 3 2006TRI VUONG ABSTRACT Serratia vaccinii, a novel bacterium isolated from blueberry microflora, increased the phenolic content of berry juices, and thus increased antioxidant activities. The fermentation capacity of Serratia was investigated with Saskatoon berries, cranberries, strawberries and grapes in both aerobic and anaerobic conditions. It was shown to be compatible with wine yeast in anaerobic fermentations, producing wine with high antioxidant activity. The effects of fermented berry juices were tested on lipopolysaccharide/inferon-gamma-activated macrophages 264.7 NO(,). Data indicated that fermented berry juices strongly inhibited activated-macrophage NO production but induced tumor necrosis factor-alpha production. [source] EVALUATION OF GLOBAL YIELD, COMPOSITION, ANTIOXIDANT ACTIVITY AND COST OF MANUFACTURING OF EXTRACTS FROM LEMON VERBENA (ALOYSIA TRIPHYLLA[L'HÉRIT.] BRITTON) AND MANGO (MANGIFERA INDICA L.) LEAVESJOURNAL OF FOOD PROCESS ENGINEERING, Issue 2 2007CAMILA G. PEREIRA ABSTRACT In this work, the global yields, composition and antioxidant activity (AA) of extracts from lemon verbena (Aloysia triphylla) and mango (Mangifera indica) leaves obtained by different separation processes were determined. Lemon verbena extracts were obtained by supercritical fluid extraction (SFE), while mango leaf extracts were obtained by SFE, low-pressure solvent extraction (LPSE) and hydrodistillation. The extract's constituents were analyzed by thin-layer chromatography, gas chromatography/mass spectrometry and gas chromatography/flame ionization detector. The AA of the extracts was evaluated by the coupled reaction of , -carotene/linolenic acid. The cost of manufacturing (COM) was estimated for the SFE extracts. Higher global yields were obtained using SFE at 350 bar/45C (1.49%) for lemon verbena and LPSE (3.04%) for mango. The AAs of the extracts were larger than that of the , -carotene for both plants. The minimum values of COM were U.S.$26.96 and 52.45/kg of extract for lemon verbena and mango, respectively. [source] THE EFFECT OF AIR-DRYING, FREEZE-DRYING AND STORAGE ON THE QUALITY AND ANTIOXIDANT ACTIVITY OF SOME SELECTED BERRIESJOURNAL OF FOOD PROCESSING AND PRESERVATION, Issue 1 2009MAGDALENA MICHALCZYK ABSTRACT The aim of this study was to analyze the effects of air-drying and freeze-drying and subsequent storage of dried products on the content of polyphenols, anthocyanins and the antioxidant properties of selected berry fruits. The material was raspberry (Rubus ideaus L.), strawberry (Fragaria ananassa Duch) and bilberry (Vaccinum myrtillus). Despite exposure to atmospheric oxygen, the stored freeze-dried fruit retained the properties of the raw material better than the air-dried product. In the case of the latter, there were considerable differences in the retention of total polyphenolic and anthocyanin content as well as antioxidant properties in the three fruit species examined. In particular, bilberry maintained a high polyphenol and anthocyanin content and high antioxidant potential despite the greatest losses of these compounds. PRACTICAL APPLICATIONS Consumer demand for food with health-promoting qualities is increasing. The food industry has intensified its efforts to provide high quality, semi-processed products that fulfil this requirement. The results presented in this work indicate that even after long-term storage and despite exposure to atmospheric oxygen, freeze-dried berries retain the antioxidant properties of the raw material to a very high degree. Therefore, lyophilisates can satisfy this particular need. Air-dried berries are much less stable during long-term storage. The dynamics of the changes occurring during the storage of both kinds of product are presented in detail. [source] EFFECT OF 1-METHYLCYCLOPROPENE ON NUTRITIONAL QUALITY AND ANTIOXIDANT ACTIVITY OF TOMATO FRUIT (SOLANUM LYCOPERSICON L.) DURING STORAGEJOURNAL OF FOOD QUALITY, Issue 2 2010MENG WANG ABSTRACT The effect of 1-methylcyclopropene (1-MCP) on postharvest quality and nutritional compounds in tomato (Solanum lycopersicon Mill.) fruit during storage was determined. The green mature tomato was exposed to 1 µL/L 1-MCP for 24 h. Thereafter, the fruit were stored at 20C and 85,95% relative humidity for 20 days. The results indicated that 1-MCP treatment significantly delayed the decrease of firmness, total soluble solids, and titratable acidity, inhibited the increase of weight loss, and suppressed the rise in respiration rate and ethylene production. Moreover, 1-MCP treatment also inhibited the lycopene accumulation and chlorophyll degradation. Ascorbic acid and soluble phenolic contents in 1-MCP-treated fruit were significantly higher than those in the control fruit. 1-MCP treatment enhanced the ferric reducing antioxidant power (FRAP) values and 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity. These results suggested that 1-MCP can be used as a commercial technology due to its ability to improve nutritional value of tomato fruit as well as to delay fruit ripening. PRACTICAL APPLICATIONS Tomato fruit are often harvested at mature green stage to minimize damage during transport to market, and then allowed to ripen before or during presentation in retail outlets. A limitation to marketing of tomato fruit is the time that ripe fruit remain in an acceptable condition for consumers. 1-Methylcyclopropene (1-MCP) can extend the storage life and improve postharvest quality of tomato fruit. Recently, nutritional quality is of increasing interest to the consumers because of their potential health benefits in protecting against various diseases. However, the effects of 1-MCP on nutritional compounds and antioxidant activity of tomato fruit are still unclear and need to be more precisely determined. This study can provide information on the effect of 1-MCP treatment on postharvest quality and nutritional compounds in tomato fruit during storage. The results could be applicable to improve the quality and nutritional value of tomato fruit for commercial purpose. [source] Lipid Peroxidation and Antioxidant Activities Involved in Resistance Response against Downy Mildew in Opium PoppyJOURNAL OF PHYTOPATHOLOGY, Issue 2 2010Mukesh K. Dubey Abstract The aim of this study was to observe the lipid peroxidation (LP) of cell membranes and antioxidant systems in response to inoculation of Peronospora arborescens causing downy mildew (DM) in opium poppy. Contents of the LP product, malondialdehyde (MDA) and antioxidant glutathione (GSH) were determined in leaves of two opium poppy genotypes, Pps-1 (highly resistant to DM) and Jawahar-16 (highly susceptible to DM) at different time intervals after inoculation (12 h, 24 h, 48 h and 72 h). The provided GSH content corresponded to that of total non-protein sulfhydryl groups. In leaves of Jawahar-16, a significant decrease in concentration of GSH and a persistent increase in concentration of MDA were recorded after inoculation in comparison to leaves of control plants. The continuous decrease in GSH content contributed to damage of cell membranes leading to disease development in Jawahar-16. On the other hand in a resistant genotype (Pps-1), initially at 12 h after inoculation (hai) the level of GSH was found to be high, but a transient and highly significant decrease in content of GSH and increase in content of MDA was observed at 24 hai in comparison to control plants of same genotype and also in comparison to inoculated plants of susceptible genotype (Jawahar-16). These results indicate that generation of GSH and MDA is negatively correlated during the infection process as found in the case of DM-resistant genotype Pps-1 at 24hai, which also suggests an increased need by the host plant for oxidative stress, required for hypersensitive response mediated defense mechanism. [source] Novel 3,6-Disubstituted 7H -1,2,4-Triazolo[3,4- b][1,3,4]thiadiazines: Synthesis, Characterization, and Evaluation of Analgesic / Anti-inflammatory, Antioxidant ActivitiesARCHIV DER PHARMAZIE, Issue 5 2009Birsen Tozkoparan Abstract In this study, the synthesis of a new series of 3,6-disubstituted-7H -1,2,4-triazolo[3,4- b][1,3,4]thiadiazine 1a,4c compounds derived from 4-amino-3-substituted-1,2,4-triazole-5-thiones 1,4 is described. All of the synthesized compounds were screened for their possible analgesic / anti-inflammatory, antioxidant activities and gastric toxicity. The compound 2c was found to have both significant analgesic and consistent anti-inflammatory activity without inducing any gastric lesions along with minimal lipid peroxidation. A deep insight into the structures of the active compounds revealed that the compounds carrying an electron withdrawing group (a chloride or fluoride) on the phenyl ring at 6-position of the condensed heterocyclic derivatives exhibited noticeable higher activity. [source] ChemInform Abstract: Synthesis and Evaluation of Analgesic, Antiinflammatory and Antioxidant Activities of New 6-Acyl-3-alkyl-5-methyl-2(3H)-benzoxazolones.CHEMINFORM, Issue 51 2008Meric Koksal Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a "Full Text" option. The original article is trackable via the "References" option. [source] ChemInform Abstract: Synthesis and Antioxidant Activities of 3,5-Dialkoxy-4-hydroxycinnamamides.CHEMINFORM, Issue 37 2008Tae-Souk Kang Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a "Full Text" option. The original article is trackable via the "References" option. [source] New Diels,Alder Type Adducts from Morus macroura and Their Antioxidant Activities.CHEMINFORM, Issue 16 2005Sheng-Jun Dai Abstract For Abstract see ChemInform Abstract in Full Text. [source] Antioxidant Activity of Degradable Polymer Poly(trolox ester) to Suppress Oxidative Stress Injury in the CellsADVANCED FUNCTIONAL MATERIALS, Issue 1 2010Paritosh P. Wattamwar Abstract Oxidative stress is a pathological condition that has been implicated as a central player in a variety of diseases, including vascular and neurodegenerative diseases. More recently, oxidative stress has also been shown to be involved in the biological incompatibility of many materials, especially at the nanoscale. As such, there is a critical need for new biomaterials that can inhibit this response, improving the compatibility of medical devices. In this work, trolox, a synthetic antioxidant and water-soluble analogue of Vitamin E, is polymerized to form an oxidation active polymer as a new class of biomaterial. Synthesized poly(trolox ester) polymers were formulated into nanoparticles using a single emulsion technique, and their size was controlled by changing the polymer concentration in the organic solvent. Nanoparticle cytotoxicity, protective effects against cellular oxidative stress, and degradation kinetics were all evaluated. Poly(trolox ester) nanoparticles were found to have little to no cytotoxicity and were capable of suppressing cellular oxidative stress induced by cobalt nanoparticles. In vitro degradation studies of poly(trolox ester) nanoparticles indicate that the antioxidant activity of nanoparticles was derived from its enzymatic degradation to release active antioxidants. [source] Influence of Cooking Methods on Antioxidant Activity of VegetablesJOURNAL OF FOOD SCIENCE, Issue 3 2009A. M. Jiménez-Monreal ABSTRACT:, The influence of home cooking methods (boiling, microwaving, pressure-cooking, griddling, frying, and baking) on the antioxidant activity of vegetables has been evaluated in 20 vegetables, using different antioxidant activity assays (lipoperoxyl and hydroxyl radicals scavenging and TEAC). Artichoke was the only vegetable that kept its very high scavenging-lipoperoxyl radical capacity in all the cooking methods. The highest losses of LOO· scavenging capacity were observed in cauliflower after boiling and microwaving, pea after boiling, and zucchini after boiling and frying. Beetroot, green bean, and garlic kept their antioxidant activity after most cooking treatments. Swiss chard and pepper lost OH· scavenging capacity in all the processes. Celery increased its antioxidant capacity in all the cooking methods, except boiling when it lost 14%. Analysis of the ABTS radical scavenging capacity of the different vegetables showed that the highest losses occurred in garlic with all the methods, except microwaving. Among the vegetables that increased their TEAC values were green bean, celery, and carrot after all cooking methods (except green bean after boiling). These 3 types of vegetables showed a low ABTS radical scavenging capacity. ccording to the method of analysis chosen, griddling, microwave cooking, and baking alternately produce the lowest losses, while pressure-cooking and boiling lead to the greatest losses; frying occupies an intermediate position. In short, water is not the cook's best friend when it comes to preparing vegetables. [source] Effect of Yam (Dioscorea alata Compared to Dioscorea japonica) on Gastrointestinal Function and Antioxidant Activity in MiceJOURNAL OF FOOD SCIENCE, Issue 7 2006Cheng-Chin Hsu ABSTRACT:, Effects of Chinese yam (Dioscorea alata) and Japanese yam (Dioscorea japonica) on gastrointestinal functions including intestinal microflora and intestinal enzymes' activities, as well as antioxidant protection against lipopolysaccharide (LPS)-induced oxidative damage, in Balb/cA mice were examined. In part I, mice were fed yam-supplemented diet for 4 or 8 wk, and killed with carbon dioxide. In part II, mice were fed yam-supplemented diet for 4 wk, and followed by intraperitoneal LPS treatment (i.p. 4 mg/kg bodyweight). The intake of Chinese yam and Japanese yam significantly changed intestinal microflora, in which the colony numbers of Bifidobacterium and Lactobacillus were increased and the colony numbers of Clostridium perfringens were decreased (P < 0.05). The intake of both Chinese and Japanese yams also significantly elevated the activity of leucine aminopeptidase and lipase (P < 0.05), and the activities of sucrase and maltase were increased only in 20% yam-treated groups (P < 0.05). The preintake of yam significantly alleviated subsequent LPS-induced oxidative injury by decreasing lipid oxidation level and fibronectin production and elevating superoxide dismutase activity (P < 0.05). Both Chinese and Japanese yams contained dietary fibers, polyphenols, and flavonoids, which may contribute to the observed gastrointestinal function and antioxidant protection. These results suggest that both Chinese yam and Japanese yam were beneficial for intestinal health and oxidation prevention. [source] Evaluation of Milk Mineral Antioxidant Activity in Beef Meatballs and Nitrite-cured SausageJOURNAL OF FOOD SCIENCE, Issue 4 2005Mihir N. Vasavada ABSTRACT: The objective of this study was to determine the antioxidant activity of 1.5% milk mineral (MM) added to uncured cooked beef meatballs and to evaluate possible synergistic effects of MM in combination with 20-ppm or 40-ppm sodium nitrite in beef sausages. All treatments were also formulated with 1.5% salt and 10% added water. Thiobarbituric acid (TBA) values and Hunter color values were determined at 1 d, 8 d, and 15 d of storage at 2°C. Meatball cooked yield was also measured. Cooked yield was not different (P < 0.05) between control meatballs and those containing MM. As expected, treatments containing nitrite had higher redness (CIE a*) than samples without nitrite. Redness values increased with storage time in sausages containing 40-ppm nitrite. However, redness values decreased (P < 0.05) during storage for control meatballs, associated with increased lipid oxidation (higher TBA values). Lipid oxidation was lower (P < 0.05) in samples containing 1.5% MM with TBA values <1.2 after 15 d of storage compared with 6.1 for control samples. There was no synergistic inhibition of lipid oxidation in samples containing 20-ppm or 40-ppm sodium nitrite plus 1.5% MM. Milk mineral alone at 1.5% of meat weight was sufficient for inhibition of lipid oxidation in cooked beef samples. [source] Effects of Hot Rehydration in the Presence of Hydrogen Peroxide on Microbial Quality, Texture, Color, and Antioxidant Activity of Cold-stored Intermediate-moisture Sun-dried FigsJOURNAL OF FOOD SCIENCE, Issue 3 2005Dilek Demirbüker ABSTRACT: Pectin methylesterase (PME) causes considerable softening in intermediate-moisture (IM) figs rehydrated at 30°C and cold stored at 28% to 29% moisture content. Rehydration of figs at 80°C for 16 min inactivated PME partially (25,30%), but this did not prevent the softening over 3 mo of cold storage. Also, heating did not reduce the microbial load of figs significantly and increased their browning. In contrast, rehydration of figs 1st in 2.5% H2O2 at 80°C for 8 min and then in water at 80°C for 8 min reduced the microbial load of IM figs significantly, turned their brown color to yellow-light brown, and maintained their desired textural properties. The residual H2O2 in IM figs decomposed in 3 or 1.5 wk by the in situ catalase or by application of the iron (II) sulfate-ascorbic acid residue elimination method, respectively. Hot rehydration did not affect the antioxidant activity of IM figs, but treatment of figs with H2O2 increased their antioxidant activity slightly. These results indicate that the hot rehydration of figs in the presence of H2O2 and cold storage may be applied to obtain safe and SO2 -free light-colored IM fig products. [source] Antioxidant Activity of Crude Extract, Alkaloid Fraction, and Flavonoid Fraction from Boldo (Peumus boldus Molina) LeavesJOURNAL OF FOOD SCIENCE, Issue 5 2004N. Quezada ABSTRACT: Boldo is an endemic plant from Chile widely used in folk medicine, whose biological (mainly antioxidant) activity has been attributed to the presence of the alkaloid boldine. The aim of this study was to determine the contribution of the flavonoid and other crude fractions from boldo leaves to the antioxidant activity of extracts. The main constituent in the flavonoid fraction was also isolated. The antioxidant activity and reducing power of crude boldo extract and fractions were measured and compared with natural and synthetic antioxidants. The antioxidant activity of boldo leaf extracts came mainly from the flavonoid fraction (44.1%) followed by the alkaloid fraction (15.6%), with catechin and boldine being the main contributors of the antioxidant activity of these 2 fractions (60.9% and 35.6% of the total activity, respectively). On the basis of these results, we propose to use catechin and boldine as markers for the antioxidant activity of boldo leaves. Tailor-made antioxidants to be used in foods can be prepared by enriching these 2 fractions. [source] Control of Foodborne Pathogenic and Spoilage Bacteria by Garcinol and Garcinia indicaextracts, and their Antioxidant ActivityJOURNAL OF FOOD SCIENCE, Issue 3 2004P. S. NEGI ABSTRACT: Spent rinds of Garcinia indicawere extracted with hexane and benzene using a Soxhlet extractor for 4 h. The major compound present in both extracts was found to be garcinol, as confirmed by fractionation and spectroscopic studies. The minimum inhibitory concentrations of hexane extract, benzene extract, and garcinol against a few Gram-positive and Gram-negative bacteria were in the range of 15 to 1000, 20 to 1250, and 1.5 to 500 ppm, respectively. The antioxidant activity of these fractions at 25 ppm was 63.2%, 61.7%, and 92.4%, respectively, as evaluated by the 1,1-diphenyl-2-picrylhydrazyl method. Hexane extract, benzene extract, and garcinol showed 1027, 985.5, and 1195.9 ,mol/g of ascorbic acid equivalents, respectively, at 100 ppm concentration using the phosphomolybdenum method. These findings may be useful for possible application of the previously described fractions as biopreservatives. [source] Effect of Equivalent Thermal Treatments on the Color and the Antioxidant Activity of Tomato PureeJOURNAL OF FOOD SCIENCE, Issue 9 2002M. Anese ABSTRACT: The influence of different heat treatments on color and antioxidant properties of tomato purees was investigated. The treatments were designed to produce the same total thermal effect against spoilage microorganisms. Although the development of nonenzymatic browning reactions occurred by increasing process temperature, no changes in redness were observed in the heated samples, due to the "masking" effect of lycopene. Also, the heat treatments had equivalent effect on the chain-breaking activity of the aqueous and lycopene tomato fractions. However the redox potential values increased as the heating temperature increased. All data together showed that the thermal resistance constant z values for color and chain-breaking activity were close to 10°C, but lower than 10°C for reducing properties. [source] Effect of Sucrose Ester of Fatty Acid on the Antioxidant Activity of Milk Products on Fish Oil OxidationJOURNAL OF FOOD SCIENCE, Issue 2 2002M. Shiota ABSTRACT: Antioxidant activity of milk products and ingredients were investigated by measuring the induction time of the Rancimat test. Butter serum showed an inhibitory effect of fish oil oxidation in the presence of ,-tocopherol, which was enhanced by the addition of sucrose ester of fatty acid (SEF). This antioxidant-enhancing effect was dependent on hydrophilic-lipophilic balance (HLB) ranging from 1 to 15 of SEF. HLB 2 of SEF enhanced it most effectively. On the contrary, whole milk, skim milk, buttermilk, and whey protein concentrate did not show the inhibitory effect, and these were not improved by SEF. [source] Screening of Plant Extracts for Antioxidant Activity: a Comparative Study on Three Testing MethodsPHYTOCHEMICAL ANALYSIS, Issue 1 2002Irina I. Koleva Abstract Three methods widely employed in the evaluation of antioxidant activity, namely 2,2,-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging method, static headspace gas chromatography (HS-GC) and ,-carotene bleaching test (BCBT), have been compared with regard to their application in the screening of plant extracts. The strengths and limitations of each method have been illustrated by testing a number of extracts, of differing polarity, from plants of the genus Sideritis, and two known antioxidants (butylated hydroxytoluene and rosmarinic acid). The sample polarity was important for the exhibited activity in the BCBT and HS-GC methods but not for the DPPH method. The complex composition of the extracts and partition phenomena affected their activity in each assay. The value of the BCBT method appears to be limited to less polar samples. Although slow, the HS-GC method is preferable for assessing the antioxidant inhibitory properties on the formation of unwanted secondary volatile products. Being rapid, simple and independent of sample polarity, the DPPH method is very convenient for the quick screening of many samples for radical scavenging activity. Copyright © 2001 John Wiley & Sons, Ltd. [source] Synthesis and Antioxidant Activity of New Pyridines Containing Gallate MoietiesARCHIV DER PHARMAZIE, Issue 9 2010Nora M. A. El-Ebiary Abstract Pyridines containing the galloyl moiety have been prepared utilizing 4-acetyl pyrogallol. In addition, fused pyridines were synthesized from the obtained pyridines via further chemical transformations. The results indicated that compound 4a showed stronger DPPH scavenging activity than the other compounds, and the scavenging effect decreased in the following order 4a,>,t-BHQ,>,2a,>,2b,>,3a,>,3b,>,4b. Accordingly, other antioxidant assays were conducted for 4a. The results suggested that compound 4a could be a good antioxidant candidate. The absence of mortality of rats receiving 5000,mg/kg body weight of 4a as single oral dose may indicate that it could be a safe antioxidant and may be used for further studies. [source] Antioxidant Activity of Newly Synthesized 2,7-DiazaphenothiazinesARCHIV DER PHARMAZIE, Issue 5 2010Beata Morak-M, odawska Abstract A series of 19 derivatives of 2,7-diazaphenothiazine was synthesized and evaluated for their antioxidant activity bearing in mind the structural similarity with "classical" phenothiazines several of which are considered powerful antioxidants. Among the new derivatives that inhibited in vitro Fe2+/ascorbate-induced lipid peroxidation of rat liver microsomal membranes, several exhibited significant antioxidant activity with IC50 values in the range of 64,125 ,M. Although N -substitution led to a variable degree of antioxidant activity, the latter appears to correlate with the lipophilicity (expressed as clogP values) of the substituted derivatives. Reduced lipophilicity may also explain the relatively lower protection offered by these derivatives against lipid peroxidation when compared to their "classical" phenothiazine counterparts. Thus, modification of the phenothiazine structure by a substitution of two benzene rings with pyridine rings to form this new type of azaphenothiazines does not enhance antioxidant activity, although it retains it. [source] Synthesis and Antioxidant Activity of 3-Methoxyflavones.CHEMINFORM, Issue 16 2006Ho Yoo Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF. [source] Synthesis of Novel Amino- and Acetylamino-4-methylcoumarins and Evaluation of Their Antioxidant Activity.CHEMINFORM, Issue 36 2005Yogesh K. Tyagi Abstract For Abstract see ChemInform Abstract in Full Text. [source] Polyphenols from Polygala spp. and Their Antioxidant ActivityCHEMISTRY & BIODIVERSITY, Issue 3 2004Rinaldo Cervellati Members of Polygalaceae are known to contain a variety of different polyphenolic compounds such as xanthones, flavonoids, and biphenyl derivatives. Here, we report the isolation and structural characterization of two new phenol derivatives, named alpestrin (=3,3,,5,-trimethoxy[1,1,-biphenyl]-4-ol; 10) and alpestriose,A (=6- O -benzoyl-1- O -{6- O -acetyl-3- O -[(4-hydroxy-3,5-dimethoxyphenyl)prop-2-enoyl]- , - D -fructofuranosyl}- , - D -glucopyranoside; 11), and of four known compounds (12,15) from the MeOH extract of Polygala alpestris. The relative in vitro antioxidant activities of these compounds, in comparison with other phenolic substances from Polygala vulgaris, were evaluated by means of the BriggsRauscher (BR) oscillating reaction, a method based on the inhibitory effects of antioxidant free-radical scavengers. The experimental antioxidant-activity values (relative to resorcinol as a standard) were compared with those calculated on the basis of the bond-dissociation enthalpies. The structure/activity relationships for the compounds examined are also discussed. [source] Flaxseed Lignans: Source, Biosynthesis, Metabolism, Antioxidant Activity, Bio-Active Components, and Health BenefitsCOMPREHENSIVE REVIEWS IN FOOD SCIENCE AND FOOD SAFETY, Issue 3 2010Alhassane Touré ABSTRACT:, Lignans are compounds found in a variety of plant materials including flaxseed, pumpkin seed, sesame seed, soybean, broccoli, and some berries. The major lignan in flaxseed is called secoisolariciresinol diglucoside (SDG). Once ingested, SDG is converted in the colon into active mammalian lignans, enterodiol, and entero-lactone, which have shown promise in reducing growth of cancerous tumors, especially hormone-sensitive ones such as those of the breast, endometrium, and prostate. Known for their hydrogen-donating antioxidant activity as well as their ability to complex divalent transition metal cations, lignans are propitious to human health. The extraction methods vary from simple to complex depending on extraction, separation, fractionation, identification, and detection of the analytes. Flax lignan is also a source of useful biologically active components found in plant foods, such as phytochemicals, and it is considered a functional food. The safety issues in flaxseed are also briefly discussed. [source] Polyphenolic profile and antioxidant activity of five apple cultivars grown under organic and conventional agricultural practicesINTERNATIONAL JOURNAL OF FOOD SCIENCE & TECHNOLOGY, Issue 6 2009Athanasios Valavanidis Summary The polyphenols and total antioxidant activities of five apple cultivars, grown by organic and conventional agricultural methods in neighbouring farms, were determined and compared. Total polyphenols in the whole fruit and in the peel were determined by the Folin-Ciocalteu method, and the total antioxidant activity was determined by three established methods, diphenyl picrylhydrazyl (DPPH), azinobis (3-ethylbenzthiazoline-6-sulfonic acid) (ABTS) and ferric reducing/antioxidant power (FRAP). Polyphenolic content for the whole fruit was in the range of 80,196 and for the peel 165,400 (mg Gallic Acid Equivalent (GAE)/100 g fresh weight) for both types of agricultural practices. Antioxidant activities of fruit extracts were also relatively similar and well correlated to their polyphenolic content. High-performance liquid chromatography (HPLC) analysis of the most important polyphenolics (chlorogenic acid, catechin, epicatechin, procyanidin B1 and B2, cyaniding 3-galactoside, phloridzin, quercetin 3-galactoside and quercetin 3-arabinoside) also showed that concentrations do not differentiate significantly between the organic and conventional apples. Statistical significance of differences in antioxidant activities among the same cultivars was relatively small (flesh + peel or peel only) for both types of apples. These results indicate that organic apples do not present higher antioxidant or nutritional value compared with conventionally grown ones, as far as polyphenolic content and total antioxidant activities are concerned. [source] | |||||||||||||||||||||||||||||||||||||