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.... This assay is based on the reduction of Mo(VI) to Mo(V) by the antioxidant compounds and the subsequent formation of a green phosphate/Mo(V) complex at acidic pH with a maximal absorption at 695 nm =-=[36]-=-. The obtained results, expressed as ascorbic acid equivalents (AAE), are presented in Figure 6 and Table 2. All investigated samples were active in a concentration dependent manner and their potency ...

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...nt (BHT) were evaluated by phosphomolybdenum assay, based on the reduction of Mo(VI) to Mo(V) by the antioxidant compounds and the subsequent formation of a green phosphate/Mo(V) complex at acidic pH =-=[29]-=-. The results obtained, expressed as ascorbic acid equivalents (AAE), are presented in Figure 6 and Table 2. Figure 6. Total antioxidant capacity of various L. x intermedia 'Budrovka' (LiB) and L. ang...

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...ontent of total polysaccharide in ER water solution was determined using the phenol sulfate method [19]. The total flavonoid content of the methanolic extracts was measured using a colorimetric assay =-=[20]-=-. Total polyphenol content was measured using Folin-Ciocalteu (FC) reagent methods [21]. Residual protein was determined using Bradford protein assay measurement [22]. The quantity contents (%) of com...

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...1). Itswas used 50% ethanol as blank sample. The tubesswere closed and taken to a water bath at 95 °C fors90 min, cooled and the absorbance was read insMicronal B 382 UV spectrophotometer at l 695nms(=-=PRIETO et al., 1999-=-). Each fraction was analyzedsin the following concentrations: pulps, 4 mg mL-1,sseeds, 2 mg mL-1, skins and whole fruit, 1 mg mL-1.sThe ascorbic acid (Vetec) was used as standard andsthe results were...

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...al volume of 4.6 mL and thoroughly mixed. After incubation for 10 min at room temperature, 1 mL of 20% Na2CO3 solution was added then immediately mixed and incubated for 2 h. The absorbance was read at 765 nm on a spectrophotometer (TU1800; Human Corporation, Seoul, Korea). Gallic acid of 1 mg/mL was used as the standard and the total phenolic compounds of the samples were expressed in milligram gallic acid equivalent per 100 mL (mg GAE/100 mL). 2.5. Determination of antioxidant activity The antioxidant activity of the grape peel extracts was evaluated by the phosphomolybdenum complex method (Prieto, Pineda, & Aguilar, 1999). The assay is based on the reduction of Mo(VI) to Mo (V) by the extract and subsequent formation of a green phosphate/Mo (V) complex at acid pH (Abdel-Hameed, 2009). In brief, 0.4 mL of sample solution (100 μL of grape peel extract dissolved in 1 mL of methanol) was combined with 4 mL of reagent solution containing 0.6 M sulphuric acid, 2 mM sodium phosphate and 4 mM ammonium molybdate. The blank solution contained 4 mL of reagent solution and the 1 mL of methanol. Test tubes were caped and placed in hot water for 90 min at 95 °C. After samples were cooled to room temperature, the absorbance...

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...quent formation of a green phosphate/Mo (V) complex at an acidic pH. The phosphomolybdenum method is quantitative, as the antioxidant activity is expressed as the number of equivalents of gallic acid =-=[60,61]-=-. The ME (350 mg GAE/g dry sample) showed higher antioxidant activity than the PEE (130 mg GAE/g dry sample). The ME showed higher antioxidant activity than the PEE. The effect of the ME might be due ...

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...re sensitive than a HPLC method with fluorescence detection. The reaction of antioxidants with the phosphomolybdate reagent is compatible with buffers and solvents normally used as HPLC mobile phases =-=[116]-=-. Interestingly, a reduction of reaction temperature to 27 °C in the on-line assay [80] or 37 °C in the batch assay [116] permitted some selectivity based on the nature of the antioxidant. At lower te...

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...ion of green Mo +5 complexes with a maximum absorption at 695 nm. The green complex is quite stable for several days and is not affected by various organic solvents used for polysaccharide extraction =-=[23]-=-. Corn cob xylan showed a TAC corresponding to 48.5 mg of ascorbic acid equivalent/g of xylan. This activity was similar to that observed for sulfated polysaccharides from the edible red seaweed Graci...

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...deionized water then thoroughly mixed. After incubation for 10 min at room temperature, 1 ml of 20 % Na2CO3 solution was mixed followed by incubation for 2 h at room temperature. The absorbance was read at 765 nm on a spectrophotometer (TU-1800; Human Corporation, Seoul, Korea). The calibration curve was obtained by using gallic acid and the total phenolic compounds of the samples were expressed in milligram gallic acid equivalent per ml of extract (mg GAE/ml). Determination of Total Antioxidants Total antioxidants in grape seeds extracts were evaluated by the phosphomolybdenum complex method [18]. In brief, 0.4 ml of sample solution (100 μl/ml methanol) was combined with 4 ml of reagent solution containing 0.6 M sulphuric aicd, 2 mM sodium phosphate and 4 mM ammonium molybdate. The blank solution contained 4 ml of reagent solution and 1 mL of methanol. Test tubes were caped and placed in hot water (95 °C) for 90 min. Absorbance was measured at 695 nm against blank. Ascorbic acid was used for preparing calibration curve and total antioxidants were expressed as milligram ascorbic acid equivalent per ml of extract (mg AAE/ml). 1, 1-Diphenyl-2-Picrylhydrazyl Antiradical Activity The free ...

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...e according to Benzie and Strain [15] with somemodifications. Readings of the colored product (ferrous tripyridyltriazine complex) were then measured at 593 nm. The standard curve was linear between 100 and 1000 ...