Polar paradox revisited: analogous pairs of hydrophilic and lipophilic antioxidants in linoleic acid emulsion containing Cu(II)

2013 ◽  
Vol 93 (10) ◽  
pp. 2478-2485 ◽  
Author(s):  
Temelkan Bakır ◽  
İnci Sönmezoğlu ◽  
Filiz İmer ◽  
Reşat Apak
Keyword(s):  
Linoleic Acid ◽  
Linoleic Acid Emulsion

scholarly journals Chemical Composition, Olfactory Evaluation and Antioxidant Effects of an Essential Oil of Thymus Vulgaris L. from Germany

2008 ◽  
Vol 3 (7) ◽  
pp. 1934578X0800300
Author(s):  
Ivanka Stoilova ◽  
Stefanie Bail ◽  
Gerhard Buchbauer ◽  
Albert Krastanov ◽  
Albena Stoyanova ◽  
...  
Keyword(s):  
Linoleic Acid ◽  
Essential Oil ◽  
Antiradical Activity ◽  
Thymus Vulgaris ◽  
Published Data ◽  
Scavenging Effect ◽  
Phenolic Components ◽  
Linoleic Acid Emulsion ◽  
Oxidized Products ◽  
Antioxidant Effects

The composition of an essential oil of thyme from Germany was analyzed by GC/FID and GC-MS. Thirty constituents were identified with thymol (49.6%), p-cymene (16.4%), γ-terpinene (8.0%), linalool (4.6%) and carvacrol (4.0%) as the main compounds. In addition, olfactory evaluations were made of the thyme sample, as well as correlations of odor-impressions of the single constituents with published data. A pleasant aroma, characteristic of thyme oils was determined, with some main and minor constituents as odor-active compounds. The thyme oil possessed antiradical activity with respect to DPPH, which was greater than the activities of its major individual phenolic components, carvacrol and thymol. The oil also demonstrated a scavenging effect with respect to hydroxyl radicals (OH•), exceeding the effect exercised on the DPPH radical, the respective concentrations resulting in a 50% inhibition (IC50) being 41.4 μg/mL for DPPH and 2.9 μg/mL for OH•. Scavenging of the superoxide radical at a concentration of 50 μg/mL was 76.9%. Thyme essential oil revealed antioxidant activity in a model system comprised of a linoleic acid emulsion where, at a concentration of 0.05%, it caused 59.5% inhibition of conjugated dienes formation and 72.4% inhibition of the generation of secondary oxidized products from linoleic acid.

scholarly journals Chemical Composition, Olfactory Evaluation and Antioxidant Effects of the Leaf Essential Oil of Corymbia citriodora (Hook) from China

2007 ◽  
Vol 2 (5) ◽  
pp. 1934578X0700200 ◽  
Author(s):  
Leopold Jirovetz ◽  
Stefanie Bail ◽  
Gerhard Buchbauer ◽  
Ivanka Stoilova ◽  
Albert Krastanov ◽  
...  
Keyword(s):  
Linoleic Acid ◽  
Chemical Composition ◽  
Essential Oil ◽  
Antioxidant Activities ◽  
Oh Radicals ◽  
Leaf Essential Oil ◽  
Corymbia Citriodora ◽  
Linoleic Acid Emulsion ◽  
Oxidized Products ◽  
Antioxidant Effects

The chemical composition of a sample of lemon eucalyptus essential oil ( Corymbia citriodora) from China was determined by GC/FID and GC/MS. Citronellal (76.3%), citronellol (5.7%) and neo-isopulegol (5.5%) were the major components. The odor of the sample was evaluated as fresh, citrus-like and mildly fruity, with a pleasant woody background note. Lemon eucalyptus oil was found to exhibit antiradical activity with respect to DPPH and hydroxyl (OH•) radicals. The effect exercised on OH• radicals significantly exceeded that observed for the DPPH radical – the respective concentrations for 50% inhibition of the radicals were 0.38 μg/mL for OH• and 344.0 μg/mL for DPPH. Furthermore, the essential oil revealed antioxidant activities in a model system comprised of a linoleic acid emulsion. At a concentration of 0.1%, inhibition of conjugated dienes-formation by 59.8% was observed and the formation of secondary oxidized products of linoleic acid by 84.7%.

Antioxidative Activity of Protein Hydrolysates from Spanish Mackerel by Alcalase

2011 ◽  
Vol 236-238 ◽  
pp. 2890-2893 ◽  
Author(s):  
Jun Juan Xiong ◽  
Li Jun Ding ◽  
Xue Ling Lai
Keyword(s):  
Linoleic Acid ◽  
Antioxidative Activity ◽  
Antioxidant Activities ◽  
Radical Scavenging ◽  
Reducing Power ◽  
Protein Hydrolysates ◽  
Antioxidant Peptide ◽  
Spanish Mackerel ◽  
Radical Scavenging Properties ◽  
Linoleic Acid Emulsion

To utilize low-value fish, Spanish mackerel protein was hydrolyzed using alcalase for production of antioxidant peptide. The antioxidant activities of antioxidant peptide from Spanish mackerel protein were evaluated. Results: The radical-scavenging properties on hydroxyl and superoxide of protein hydrolysates were 53.11% and 23.1%. And their reducing power was increased with the peptide content of the hydrolysates. The hydrolysates significantly inhibited lipid peroxidation in linoleic acid emulsion system, and effectively inhibit autoxidation of linoleic acid; and the inhibition ability increased with the increasing of peptide content in hydrolysates. The hydrolysates inhibited the activity of LOX to a certain extent. Conclusion: The hydrolysates from Spanish mackerel protein exhibited high antioxidative activity.

scholarly journals Chemical Composition, Olfactory Evaluation and Antioxidant Effects of the Essential oil of Origanum Majorana L. from Albania

2008 ◽  
Vol 3 (7) ◽  
pp. 1934578X0800300 ◽  
Author(s):  
Erich Schmidt ◽  
Stefanie Bail ◽  
Gerhard Buchbauer ◽  
Ivanka Stoilova ◽  
Albert Krastanov ◽  
...  
Keyword(s):  
Linoleic Acid ◽  
Chemical Composition ◽  
Essential Oil ◽  
Antiradical Activity ◽  
Scavenging Effect ◽  
Emulsion Model ◽  
Origanum Majorana ◽  
Linoleic Acid Emulsion ◽  
Oxidized Products ◽  
Antioxidant Effects

The chemical composition of marjoram essential oil ( Origanum majorana L.) was determined by GC/FID and GC/MS. As major compounds of the oil terpinen-4-ol (21.3%), trans-sabinene hydrate (15.5%), γ-terpinene (14.0%), and α-terpinene (8.9%) were identified. The odour profile and evaluation of marjoram essential oil was established. Marjoram oil has antiradical activity with regard to DPPH, exceeding that of the phenolic component thymol. The oil exhibited scavenging effect on the hydroxyl radicals (OH•), as well, which substantially exceeded that towards the DPPH radical - the respective concentrations for 50% inhibition of the radicals (IC50) were 0.11μg/mL for OH• and 341.0μg/mL for DPPH. Marjoram essential oil was capable of antioxidant activity in a linoleic acid emulsion model system, where at concentration of 0.05% it inhibited conjugated dienes formation by 50.00% and the generation of linoleic acid secondary oxidized products by 79.85%.

scholarly journals Development of a Method Suitable for High-Throughput Screening to Measure Antioxidant Activity in a Linoleic Acid Emulsion

Antioxidants ◽  
2019 ◽  
Vol 8 (9) ◽  
pp. 366 ◽  
Author(s):  
Md Ahsan Ghani ◽  
Celia Barril ◽  
Danny R. Bedgood ◽  
Paul D. Prenzler
Keyword(s):  
Antioxidant Activity ◽  
Linoleic Acid ◽  
Reaction Time ◽  
High Throughput Screening ◽  
Thiobarbituric Acid ◽  
Thiobarbituric Acid Reactive Substances ◽  
Large Numbers ◽  
Increasing Temperature ◽  
Linoleic Acid Emulsion ◽  
Chemical Class

An improved system for measuring antioxidant activity via thiobarbituric acid reactive substances and ferric thiocyanate assays is reported, on the basis of oxidation of a linoleic acid (LA) emulsion. Oxidation times were reduced from 20 h to 5 h by increasing the reaction temperature from 37 °C to 50 °C and with an acceptable precision of <10% coefficient of variation (CV). Antioxidants varying in polarity and chemical class—250 µM Trolox, quercetin, ascorbic acid and gallic acid—were used for method optimisation. Further reductions in reaction time were investigated through the addition of catalysts, oxygen initiators or increasing temperature to 60 °C; however, antioxidant activity varied from that established at 37 °C and 20 h reaction time—the method validation conditions. Further validation of the method was achieved with catechin, epicatechin, caffeic acid and α-tocopherol, with results at 50 °C and 5 h comparable to those at 37 °C and 20 h. The improved assay has the potential to rapidly screen antioxidants of various polarities, thus making it useful in studies where large numbers of plant extracts require testing. Furthermore, as this assay involves protection of a lipid, the assay is likely to provide complementary information to well-established tests, such as the 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay.

scholarly journals Chemical Composition, Olfactory Evaluation and Antioxidant Effects of an Essential Oil of Origanum Vulgare L. from Bosnia

2008 ◽  
Vol 3 (7) ◽  
pp. 1934578X0800300 ◽  
Author(s):  
Ivanka Stoilova ◽  
Stefanie Bail ◽  
Gerhard Buchbauer ◽  
Albert Krastanov ◽  
Albena Stoyanova ◽  
...  
Keyword(s):  
Linoleic Acid ◽  
Chemical Composition ◽  
Essential Oil ◽  
Antiradical Activity ◽  
Origanum Vulgare ◽  
Emulsion Model ◽  
Oregano Oil ◽  
Linoleic Acid Emulsion ◽  
Oxidized Products ◽  
Antioxidant Effects

The chemical composition of an essential oil of oregano ( Origanum vulgare L.) from Bosnia was analyzed by GC/FID and GC-MS. In total, 33 constituents were identified and carvacrol (66.2%), p-cymene (9.1%), γ-terpinene (7.3%) and β-caryophyllene (4.1%) were found to be the main compounds. In addition, olfactory evaluation data of the sample and correlations with the odor attributes of the single components are presented to explain the complex aroma impression of this essential oil. The oil possessed antiradical activity with respect to DPPH radicals, exceeding that of its major phenolic component, carvacrol. The oil also revealed scavenging potential with respect to hydroxyl radicals (OH•), which was superior to that towards the DPPH radical; the respective concentrations needed for 50% inhibition (IC50) were 53.8 μg/mL for DPPH and 0.31 μg/mL for OH•. The superoxide scavenging activity of oregano oil was 82.7% at 50 μg/mL. The oil also demonstrated antioxidant activity in a linoleic acid emulsion model system; at 0.05% concentration it inhibited conjugated dienes formation by 69.0% and the generation of secondary oxidized products from linoleic acid by 73.1 %.

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