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Trolox Equivalent Antioxidant Capacity (trolox + equivalent_antioxidant_capacity)
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] Distribution of 127 edible plant species for antioxidant activities by two assaysJOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE, Issue 14 2006Ray-Yu Yang Abstract Epidemiological studies have demonstrated the protective effects of fruit and vegetable consumption on human health. A total of 150 edible plants representing 127 species were evaluated for Trolox equivalent antioxidant capacity (TEAC) and superoxide scavenging (SOS) activity. Distributions of vegetables for TEAC and SOS were not continuous but highly skewed. TEAC values on a dry weight basis ranged from 0 to 2105 µmol TE g,1 and SOS values ranged from 0 to 6206 µmol ascorbate equivalent (AE) g,1. The majority of vegetables clustered within 200 µmol TE g,1 and 400 µmol AE g,1. Vegetable species were grouped into six classes after natural logarithm transformation of TEAC and SOS values. Most highly consumed vegetables fell in the very low to medium classes. Species in the very high class for both TEAC and SOS included leaves of Cedrela sinensis (Chinese cedar), Oroxylum indicum (Damocles tree), Cassia siamea (cassod tree) and Cassia tora (sickle senna). Edible plants high in antioxidant activity (AOA) were mostly perennial and underutilised crops, while commonly consumed vegetables were generally low in AOA. There is great potential to increase dietary antioxidants and improve human health through consumption of diverse vegetable species, especially those high in AOA. Copyright © 2006 Society of Chemical Industry [source] Modulation of oxidative cell damage by reconstituted mixtures of phenolic apple juice extracts in human colon cell linesMOLECULAR NUTRITION & FOOD RESEARCH (FORMERLY NAHRUNG/FOOD), Issue 4-5 2006Sandra Schaefer Abstract Diets rich in fruits and vegetables are associated with a lower risk of tumour induction in the intestine and other sites. Apple juice with high amounts of antioxidative phenolics might protect the intestine against reactive oxygen species-mediated cell damage. We investigated to which extent the preventive effectiveness of polyphenolic juice extracts is governed by the amounts of five major constituents (rutin, phloridzin, chlorogenic acid, caffeic acid and epicatechin). In human colon cell lines (Caco-2, HT29), reconstituted mixtures of these phenolics were investigated in comparison to the original juice extracts, originating from cider and table apples. Parameters studied were (oxidative) DNA damage (Comet assay), cellular redox status (dichlorofluorescein assay) and Trolox equivalent antioxidant capacity (TEAC). The TEAC of the reconstituted mixtures was higher compared to the respective original extracts (4.7,7.3 mM vs. 3.6,4.2 mM Trolox). After 24 h cell incubation, menadione-induced (oxidative) DNA damage was more effectively reduced by the reconstituted mixtures (1,100 ,g/mL, 24 h), as compared to the original extracts. In contrast, the cellular ROS level was reduced to a rather similar extent by original extracts and reconstituted mixtures. The results lead to the conclusion that the selected constituents in their authentic proportions substantially account for the antioxidative effectiveness of phenolic apple juice extracts. [source] Effects of genotype, location and baking on the phenolic content and some antioxidant properties of cereal speciesINTERNATIONAL JOURNAL OF FOOD SCIENCE & TECHNOLOGY, Issue 1 2010Valeria Menga Summary In order to assess the effect of genotype, location and their interaction on total phenolic content (TPC) of chemical extracts, the whole grains of durum and soft wheat, oat, barley and triticale were evaluated. Data showed differences in phenolic content of chemical extracts among cereal species and the analysis of variance confirmed the key role of location. Besides TPC and trolox equivalent antioxidant capacity (TEAC) values assessed by chemical extraction were compared with those obtained with an in vitro digestive enzymatic extraction. Differences were found between methanolic and enzymatic extracts, and data confirmed that enzymatic technique enhanced extraction of antioxidants but pointed out lesser differences among cereal types. The breads obtained by flours enriched with different levels of bran were also evaluated. Chemical extracts highlighted the increasing levels of antioxidants according to bran enrichments, without pointing out changes caused by baking. The enzymatic extraction instead did not show differences regarding to bran enrichments, but documented a loss in antioxidant properties of breads in respect to corresponding flours. On the other hand the scarce differences between flours and corresponding breads did not allow asserting that baking modified the TPC and TEAC, independently of the extraction methods used. Indeed, during baking process, also the observed phenolic acids profile variations did not vary the antioxidant properties of breads. [source] ANTIOXIDANT AND ANTIMICROBIAL ACTIVITY OF DIFFERENT FLORAL ORIGIN HONEYS FROM TURKIYEJOURNAL OF FOOD BIOCHEMISTRY, Issue 2010ESRA ULUSOY ABSTRACT The bioactivities of phenolic extracts of nine Turkish honeys from different floral sources were investigated. The antioxidant properties of the extracts were assessed by ferric reducing/antioxidant power (FRAP) assay, 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical-scavenging activity and cupric reducing antioxidant capacity (CUPRAC) assay. The total phenolic contents measured by Folin,Ciocalteau method varied from 66 to 223 mg/g extract as gallic acid equivalent. The antioxidant activities found with CUPRAC, expressed as trolox equivalent antioxidant capacity, ranged from 124.8 to 532 µmol/g, those determined with DPPH· expressed as IC50 ranged from 84 to 296 µg/mL, and those determined with FRAP expressed as trolox equivalent were in 33,166 µmol/g range. The antioxidant activities showed a marked correlation with total phenolics. In the antimicrobial tests using six bacteria and a yeast, Escherichia coli was moderately sensitive to each extract. There was no correlation between antimicrobial activity and total phenolic contents. PRACTICAL APPLICATIONS Honey has functional properties and promotes human health, and such properties depend largely on the floral source. Although studies on screening the antimicrobial and antioxidant activity of raw honey samples have been done densely, studies on phenolic compounds of honey are very limited. The present study demonstrates that honey phenolic compounds are partially responsible for honey antioxidant activity, displaying the relevance of honey as both healthy foodstuff and source of antioxidant. [source] 1-Methylcyclopropene affects the antioxidant system of apricots (Prunus armeniaca L. cv. Búlida) during storage at low temperatureJOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE, Issue 4 2010Isabel Egea Abstract BACKGROUND: Apricots (Prunus armeniaca cv. Búlida) were treated with 1 mL L,1 1-methylcyclopropene (1-MCP) immediately after harvest and stored in air at 2 °C for 21 days. Antioxidant levels (ascorbic acid and carotenoids), enzymatic antioxidant activities (superoxide dismutase (SOD) and unspecific peroxidase (POX)) and total antioxidant capacity (trolox equivalent antioxidant capacity (TEAC)) were determined. The level of oxidative stress was also established by measuring ion leakage during storage. The changes in the antioxidant potential of apricots were related to the capacity of 1-MCP to increase their commercial life. RESULTS: 1-MCP-treated fruits exhibited higher SOD activity, whereas POX activity was significantly higher only after 21 days at 2 °C. Treated fruits also exhibited better retention of ascorbate and carotenoids and higher TEAC during storage. In accordance with these observations, lower ion leakage values were detected in 1-MCP-treated apricots. CONCLUSION: Taken together, these results suggest that 1-MCP conferred a greater resistance to oxidative stress. This, along with the reduction in ethylene production, could contribute to the increase in commercial life and nutritional value observed in 1-MCP-treated apricots. Copyright © 2010 Society of Chemical Industry [source] | ||||||||||