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Author: search.filters.author.Park, Yong SeoSubject: search.filters.subject.Antioxidant compounds

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    Bioactive compounds and antioxidant potential in fresh and dried Jaffa® sweeties, a new kind of citrus fruit
    (2004-09-01)
    Gorinstein, Shela
    ;
    Haruenkit, Ratiporn
    ;
    Park, Yong Seo
    ;
    Jung, Soon Teck
    ;
    Zachwieja, Zofia
    Bioactive compounds in the edible parts of fresh and dried Jaffa® sweeties, a new kind of citrus fruit, were analysed and their antioxidant capacities were assessed. Antioxidant-rich fractions were extracted from fresh and dried sweeties with 1.2 M HCl in methanol/water (1:1 v/v), and the antioxidant activities of these extracts were evaluated. Using the β-carotene/linoleate model system, the extracts from equivalent quantities of fresh and dried sweeties showed 89 and 87% antioxidant activity respectively. Similarly, using the DPPH radical-scavenging method, the extracts showed 87 and 85% antioxidant activity respectively. The best correlations were between caffeic acid content and β-carotene and DPPH antioxidant activity values (r = 0.9849 and 0.9798 respectively, p = 0.005). Both fresh and dried sweeties are bioactive natural products; when fresh fruits are not available, properly dried sweeties could be used as a substitute. © 2004 Society of Chemical Industry.
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    Characterization of antioxidant compounds in Jaffa sweeties and white grapefruits
    (2004-01-01)
    Gorinstein, Shela
    ;
    Cvikrová, Milena
    ;
    Machackova, Ivana
    ;
    Haruenkit, Ratiporn
    ;
    Park, Yong Seo
    Antioxidant compounds and the antioxidative activities of new Israeli citrus fruit sweetie [(Oroblanco, pummelo-grapefruit hybrid (Citrus grandisxC. paradisi)] were compared with the better-known white grapefruit. Total and free phenols were determined with the Folin-Ciocalteu reagent, phenolic acids (free, esters and glycosides) by HPLC analysis and anthocyanins spectrophotometrically. The antioxidant activities were estimated with two scavenging radicals: 2, 2′-azinobis (3-ethylbenzothiazoline-6-sulfonate)- (ABTS) and nitric oxide (NO). Free radical scavenging properties of sweetie and grapefruit were evaluated by β-carotene bleaching (β-carotene). The results of kinetic reactions showed that both fruits differed in their capacities to quench these radicals and sweetie showed more antioxidative activity than grapefruit. Trans-hydroxycinnamic acids (caffeic, p-coumaric, ferulic, and sinapic) were more abundant in grapefruits than in sweeties. High correlation was observed between antioxidative activities and phenols (R<sup>2</sup>=0.94). Both fruits have high concentrations of natural antioxidants with high antioxidative activities. Phenol content and the antioxidative potential are significantly higher in sweetie than in grapefruit. The higher antioxidant capacity of sweetie could make these new kinds of citrus fruits preferable for diets. In summary, the studied citrus fruit has high total phenolics and high antioxidant activities in vitro. Consumption of this fruit may contribute to an adequate intake of antioxidant phytochemicals. © 2003 Elsevier Ltd. All rights reserved.
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    Comparison of the contents of the main biochemical compounds and the antioxidant activity of some Spanish olive oils as determined by four different radical scavenging tests
    (2003-03-01)
    Gorinstein, Shela
    ;
    Martin-Belloso, Olga
    ;
    Katrich, Elena
    ;
    Lojek, Antonin
    ;
    Číž, Milan
    The aim of this study was to compare the contents of the main biochemical compounds and the antioxidant capacity of five Spanish olive oils by four different antioxidant tests and to find out the most valuable oil for disease preventing diets. Fatty acids, sterols and individual antioxidant compounds in Arbequina, Hojiblanca, Extra Virgin, Picual and Lampante Spanish olive oils were determined. Antioxidant activities were done as well using different radical scavenging activities: total radical-trapping antioxidative potential by ABAP (TRAP-ABAP), radical scavenging activity by DPPH (RSA-DPPH), antioxidant assay by β-carotene-linoleate model system (AA-β-carotene) and total antioxidant status by ABTS (TAA-ABTS). The highest content of all studied antioxidant compounds (353; 329; 4.6 and 2.7 mg/kg for tocopherols, tocotrienols, polyphenols and o-diphenols, respectively) was found in Extra Virgin oil. Also the highest antioxidant capacity was observed in Extra Virgin oil (668nmol/ml; 29.4%; 40.4% and 2.64 mmolTE/kg for TRAP-ABAP, RSA-DPPH, AA- β-carotene and TAA-ABTS, respectively). The correlation between total phenols and antioxidant capacities measured by four methods was very high, but the highest for the β-carotene (R<sup>2</sup> = 0.9958). In conclusion, the best method for determination of the antioxidant capacity of olive oils is the β-carotene test. Extra Virgin olive oil has high organoleptic properties and the highest antioxidant activity. The above-mentioned makes this oil a preferable choice for diseases preventing diets. © 2003 Elsevier Inc. All rights reserved.